RxJava 各种操作符（2）

最新推荐文章于 2022-07-30 13:02:51 发布

苏白2016

最新推荐文章于 2022-07-30 13:02:51 发布

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本文详细介绍了RxJava中的Transforming Observables操作符，包括buffer、FlatMap、GroupBy、Map和Scan等，通过具体示例展示了这些操作符如何帮助开发者更高效地处理数据流。

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RxJava 各种操作符（2） - Transforming Observables

buffer, FlatMap, GroupBy, Map, Scan, Window

buffer

buffer操作符周期性地收集源Observable产生的结果到列表中，并把这个列表提交给订阅者，订阅者处理后，清空buffer列表，同时接收下一次收集的结果并提交给订阅者，周而复始。
一旦源Observable在产生结果的过程中出现异常，即使buffer已经存在收集到的结果，订阅者也会马上收到这个异常，并结束整个过程。

buffer操作符

<code class="hljs java has-numbering" style="display: block; padding: 0px; color: inherit; box-sizing: border-box; font-family: 'Source Code Pro', monospace;font-size:undefined; white-space: pre; border-radius: 0px; word-wrap: normal; background: transparent;"><span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">//定义邮件内容</span>
        <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">final</span> String[] mails = <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">new</span> String[]{<span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">"Here is an email!"</span>, <span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">"Another email!"</span>, <span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">"Yet another email!"</span>};
        <span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">//每隔1秒就随机发布一封邮件</span>
        Observable<String> endlessMail = Observable.create(<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">new</span> Observable.OnSubscribe<String>() {
            <span class="hljs-annotation" style="color: rgb(155, 133, 157); box-sizing: border-box;">@Override</span>
            <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">public</span> <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">void</span> <span class="hljs-title" style="box-sizing: border-box;">call</span>(Subscriber<? <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">super</span> String> subscriber) {
                <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">try</span> {
                    <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">if</span> (subscriber.isUnsubscribed()) <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">return</span>;
                    Random random = <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">new</span> Random();
                    <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">while</span> (<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">true</span>) {
                        String mail = mails[random.nextInt(mails.length)];
                        subscriber.onNext(mail);
                        Thread.sleep(<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1000</span>);
                    }
                } <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">catch</span> (Exception ex) {
                    subscriber.onError(ex);
                }
            }
        }).subscribeOn(Schedulers.io());
        <span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">//把上面产生的邮件内容缓存到列表中，并每隔3秒通知订阅者</span>
        endlessMail.buffer(<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">3</span>, TimeUnit.SECONDS).subscribe(<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">new</span> Action1<List<String>>() {
            <span class="hljs-annotation" style="color: rgb(155, 133, 157); box-sizing: border-box;">@Override</span>
            <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">public</span> <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">void</span> <span class="hljs-title" style="box-sizing: border-box;">call</span>(List<String> list) {

                System.out.println(String.format(<span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">"You've got %d new messages!  Here they are!"</span>, list.size()));
                <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">for</span> (<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">int</span> i = <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">0</span>; i < list.size(); i++)
                    System.out.println(<span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">"**"</span> + list.get(i).toString());
            }
        });</code><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li><li style="box-sizing: border-box; padding: 0px 5px;">2</li><li style="box-sizing: border-box; padding: 0px 5px;">3</li><li style="box-sizing: border-box; padding: 0px 5px;">4</li><li style="box-sizing: border-box; padding: 0px 5px;">5</li><li style="box-sizing: border-box; padding: 0px 5px;">6</li><li style="box-sizing: border-box; padding: 0px 5px;">7</li><li style="box-sizing: border-box; padding: 0px 5px;">8</li><li style="box-sizing: border-box; padding: 0px 5px;">9</li><li style="box-sizing: border-box; padding: 0px 5px;">10</li><li style="box-sizing: border-box; padding: 0px 5px;">11</li><li style="box-sizing: border-box; padding: 0px 5px;">12</li><li style="box-sizing: border-box; padding: 0px 5px;">13</li><li style="box-sizing: border-box; padding: 0px 5px;">14</li><li style="box-sizing: border-box; padding: 0px 5px;">15</li><li style="box-sizing: border-box; padding: 0px 5px;">16</li><li style="box-sizing: border-box; padding: 0px 5px;">17</li><li style="box-sizing: border-box; padding: 0px 5px;">18</li><li style="box-sizing: border-box; padding: 0px 5px;">19</li><li style="box-sizing: border-box; padding: 0px 5px;">20</li><li style="box-sizing: border-box; padding: 0px 5px;">21</li><li style="box-sizing: border-box; padding: 0px 5px;">22</li><li style="box-sizing: border-box; padding: 0px 5px;">23</li><li style="box-sizing: border-box; padding: 0px 5px;">24</li><li style="box-sizing: border-box; padding: 0px 5px;">25</li><li style="box-sizing: border-box; padding: 0px 5px;">26</li><li style="box-sizing: border-box; padding: 0px 5px;">27</li><li style="box-sizing: border-box; padding: 0px 5px;">28</li><li style="box-sizing: border-box; padding: 0px 5px;">29</li></ul><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li><li style="box-sizing: border-box; padding: 0px 5px;">2</li><li style="box-sizing: border-box; padding: 0px 5px;">3</li><li style="box-sizing: border-box; padding: 0px 5px;">4</li><li style="box-sizing: border-box; padding: 0px 5px;">5</li><li style="box-sizing: border-box; padding: 0px 5px;">6</li><li style="box-sizing: border-box; padding: 0px 5px;">7</li><li style="box-sizing: border-box; padding: 0px 5px;">8</li><li style="box-sizing: border-box; padding: 0px 5px;">9</li><li style="box-sizing: border-box; padding: 0px 5px;">10</li><li style="box-sizing: border-box; padding: 0px 5px;">11</li><li style="box-sizing: border-box; padding: 0px 5px;">12</li><li style="box-sizing: border-box; padding: 0px 5px;">13</li><li style="box-sizing: border-box; padding: 0px 5px;">14</li><li style="box-sizing: border-box; padding: 0px 5px;">15</li><li style="box-sizing: border-box; padding: 0px 5px;">16</li><li style="box-sizing: border-box; padding: 0px 5px;">17</li><li style="box-sizing: border-box; padding: 0px 5px;">18</li><li style="box-sizing: border-box; padding: 0px 5px;">19</li><li style="box-sizing: border-box; padding: 0px 5px;">20</li><li style="box-sizing: border-box; padding: 0px 5px;">21</li><li style="box-sizing: border-box; padding: 0px 5px;">22</li><li style="box-sizing: border-box; padding: 0px 5px;">23</li><li style="box-sizing: border-box; padding: 0px 5px;">24</li><li style="box-sizing: border-box; padding: 0px 5px;">25</li><li style="box-sizing: border-box; padding: 0px 5px;">26</li><li style="box-sizing: border-box; padding: 0px 5px;">27</li><li style="box-sizing: border-box; padding: 0px 5px;">28</li><li style="box-sizing: border-box; padding: 0px 5px;">29</li></ul>

<code class="hljs erlang-repl has-numbering" style="display: block; padding: 0px; color: inherit; box-sizing: border-box; font-family: 'Source Code Pro', monospace;font-size:undefined; white-space: pre; border-radius: 0px; word-wrap: normal; background: transparent;">运行结果如下：
<span class="hljs-variable" style="color: rgb(102, 0, 102); box-sizing: border-box;">You</span>’<span class="hljs-function_or_atom" style="box-sizing: border-box;">ve</span> <span class="hljs-function_or_atom" style="box-sizing: border-box;">got</span> <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">3</span> <span class="hljs-function_or_atom" style="box-sizing: border-box;">new</span> <span class="hljs-function_or_atom" style="box-sizing: border-box;">messages</span><span class="hljs-exclamation_mark" style="box-sizing: border-box;">!</span> <span class="hljs-variable" style="color: rgb(102, 0, 102); box-sizing: border-box;">Here</span> <span class="hljs-function_or_atom" style="box-sizing: border-box;">they</span> <span class="hljs-function_or_atom" style="box-sizing: border-box;">are</span><span class="hljs-exclamation_mark" style="box-sizing: border-box;">!</span>(<span class="hljs-function_or_atom" style="box-sizing: border-box;">after</span> <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">3</span>s)
**<span class="hljs-variable" style="color: rgb(102, 0, 102); box-sizing: border-box;">Here</span> <span class="hljs-function_or_atom" style="box-sizing: border-box;">is</span> <span class="hljs-function_or_atom" style="box-sizing: border-box;">an</span> <span class="hljs-function_or_atom" style="box-sizing: border-box;">email</span><span class="hljs-exclamation_mark" style="box-sizing: border-box;">!</span>
**<span class="hljs-variable" style="color: rgb(102, 0, 102); box-sizing: border-box;">Another</span> <span class="hljs-function_or_atom" style="box-sizing: border-box;">email</span><span class="hljs-exclamation_mark" style="box-sizing: border-box;">!</span>
**<span class="hljs-variable" style="color: rgb(102, 0, 102); box-sizing: border-box;">Another</span> <span class="hljs-function_or_atom" style="box-sizing: border-box;">email</span><span class="hljs-exclamation_mark" style="box-sizing: border-box;">!</span>
<span class="hljs-variable" style="color: rgb(102, 0, 102); box-sizing: border-box;">You</span>’<span class="hljs-function_or_atom" style="box-sizing: border-box;">ve</span> <span class="hljs-function_or_atom" style="box-sizing: border-box;">got</span> <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">3</span> <span class="hljs-function_or_atom" style="box-sizing: border-box;">new</span> <span class="hljs-function_or_atom" style="box-sizing: border-box;">messages</span><span class="hljs-exclamation_mark" style="box-sizing: border-box;">!</span> <span class="hljs-variable" style="color: rgb(102, 0, 102); box-sizing: border-box;">Here</span> <span class="hljs-function_or_atom" style="box-sizing: border-box;">they</span> <span class="hljs-function_or_atom" style="box-sizing: border-box;">are</span><span class="hljs-exclamation_mark" style="box-sizing: border-box;">!</span>(<span class="hljs-function_or_atom" style="box-sizing: border-box;">after</span> <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">6</span>s)
**<span class="hljs-variable" style="color: rgb(102, 0, 102); box-sizing: border-box;">Here</span> <span class="hljs-function_or_atom" style="box-sizing: border-box;">is</span> <span class="hljs-function_or_atom" style="box-sizing: border-box;">an</span> <span class="hljs-function_or_atom" style="box-sizing: border-box;">email</span><span class="hljs-exclamation_mark" style="box-sizing: border-box;">!</span>
**<span class="hljs-variable" style="color: rgb(102, 0, 102); box-sizing: border-box;">Another</span> <span class="hljs-function_or_atom" style="box-sizing: border-box;">email</span><span class="hljs-exclamation_mark" style="box-sizing: border-box;">!</span>
**<span class="hljs-variable" style="color: rgb(102, 0, 102); box-sizing: border-box;">Here</span> <span class="hljs-function_or_atom" style="box-sizing: border-box;">is</span> <span class="hljs-function_or_atom" style="box-sizing: border-box;">an</span> <span class="hljs-function_or_atom" style="box-sizing: border-box;">email</span><span class="hljs-exclamation_mark" style="box-sizing: border-box;">!</span>
……</code><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li><li style="box-sizing: border-box; padding: 0px 5px;">2</li><li style="box-sizing: border-box; padding: 0px 5px;">3</li><li style="box-sizing: border-box; padding: 0px 5px;">4</li><li style="box-sizing: border-box; padding: 0px 5px;">5</li><li style="box-sizing: border-box; padding: 0px 5px;">6</li><li style="box-sizing: border-box; padding: 0px 5px;">7</li><li style="box-sizing: border-box; padding: 0px 5px;">8</li><li style="box-sizing: border-box; padding: 0px 5px;">9</li><li style="box-sizing: border-box; padding: 0px 5px;">10</li></ul><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li><li style="box-sizing: border-box; padding: 0px 5px;">2</li><li style="box-sizing: border-box; padding: 0px 5px;">3</li><li style="box-sizing: border-box; padding: 0px 5px;">4</li><li style="box-sizing: border-box; padding: 0px 5px;">5</li><li style="box-sizing: border-box; padding: 0px 5px;">6</li><li style="box-sizing: border-box; padding: 0px 5px;">7</li><li style="box-sizing: border-box; padding: 0px 5px;">8</li><li style="box-sizing: border-box; padding: 0px 5px;">9</li><li style="box-sizing: border-box; padding: 0px 5px;">10</li></ul>

flatMap操作符

flatMap操作符是把Observable产生的结果转换成多个Observable，然后把这多个Observable“扁平化”成一个Observable，并依次提交产生的结果给订阅者。
flatMap操作符通过传入一个函数作为参数转换源Observable，在这个函数中，你可以自定义转换规则，最后在这个函数中返回一个新的Observable，然后flatMap操作符通过合并这些Observable结果成一个Observable，并依次提交结果给订阅者。
flatMap操作符在合并Observable结果时，有可能存在交叉的情况

<code class="hljs java has-numbering" style="display: block; padding: 0px; color: inherit; box-sizing: border-box; font-family: 'Source Code Pro', monospace;font-size:undefined; white-space: pre; border-radius: 0px; word-wrap: normal; background: transparent;"><span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">private</span> Observable<File> <span class="hljs-title" style="box-sizing: border-box;">listFiles</span>(File f){
        <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">if</span>(f.isDirectory()){
            <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">return</span> Observable.from(f.listFiles()).flatMap(<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">new</span> Func1<File, Observable<File>>() {
                <span class="hljs-annotation" style="color: rgb(155, 133, 157); box-sizing: border-box;">@Override</span>
                <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">public</span> Observable<File> <span class="hljs-title" style="box-sizing: border-box;">call</span>(File file) {
                    <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">return</span> listFiles(f);
                }
            });
        } <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">else</span> {
            <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">return</span> Observable.just(f);
        }
    }


    <span class="hljs-annotation" style="color: rgb(155, 133, 157); box-sizing: border-box;">@Override</span>
    <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">public</span> <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">void</span> <span class="hljs-title" style="box-sizing: border-box;">onClick</span>(View v) {
        Observable.just(getApplicationContext().getExternalCacheDir())
                .flatMap(<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">new</span> Func1<File, Observable<File>>() {
                    <span class="hljs-annotation" style="color: rgb(155, 133, 157); box-sizing: border-box;">@Override</span>
                    <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">public</span> Observable<File> <span class="hljs-title" style="box-sizing: border-box;">call</span>(File file) {
                        <span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">//参数file是just操作符产生的结果，这里判断file是不是目录文件，如果是目录文件，则递归查找其子文件flatMap操作符神奇的地方在于，返回的结果还是一个Observable，而这个Observable其实是包含多个文件的Observable的，输出应该是ExternalCacheDir下的所有文件</span>
                        <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">return</span> listFiles(file);
                    }
                })
                .subscribe(<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">new</span> Action1<File>() {
                    <span class="hljs-annotation" style="color: rgb(155, 133, 157); box-sizing: border-box;">@Override</span>
                    <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">public</span> <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">void</span> <span class="hljs-title" style="box-sizing: border-box;">call</span>(File file) {
                        System.out.println(file.getAbsolutePath());
                    }
                });

    }</code><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li><li style="box-sizing: border-box; padding: 0px 5px;">2</li><li style="box-sizing: border-box; padding: 0px 5px;">3</li><li style="box-sizing: border-box; padding: 0px 5px;">4</li><li style="box-sizing: border-box; padding: 0px 5px;">5</li><li style="box-sizing: border-box; padding: 0px 5px;">6</li><li style="box-sizing: border-box; padding: 0px 5px;">7</li><li style="box-sizing: border-box; padding: 0px 5px;">8</li><li style="box-sizing: border-box; padding: 0px 5px;">9</li><li style="box-sizing: border-box; padding: 0px 5px;">10</li><li style="box-sizing: border-box; padding: 0px 5px;">11</li><li style="box-sizing: border-box; padding: 0px 5px;">12</li><li style="box-sizing: border-box; padding: 0px 5px;">13</li><li style="box-sizing: border-box; padding: 0px 5px;">14</li><li style="box-sizing: border-box; padding: 0px 5px;">15</li><li style="box-sizing: border-box; padding: 0px 5px;">16</li><li style="box-sizing: border-box; padding: 0px 5px;">17</li><li style="box-sizing: border-box; padding: 0px 5px;">18</li><li style="box-sizing: border-box; padding: 0px 5px;">19</li><li style="box-sizing: border-box; padding: 0px 5px;">20</li><li style="box-sizing: border-box; padding: 0px 5px;">21</li><li style="box-sizing: border-box; padding: 0px 5px;">22</li><li style="box-sizing: border-box; padding: 0px 5px;">23</li><li style="box-sizing: border-box; padding: 0px 5px;">24</li><li style="box-sizing: border-box; padding: 0px 5px;">25</li><li style="box-sizing: border-box; padding: 0px 5px;">26</li><li style="box-sizing: border-box; padding: 0px 5px;">27</li><li style="box-sizing: border-box; padding: 0px 5px;">28</li><li style="box-sizing: border-box; padding: 0px 5px;">29</li><li style="box-sizing: border-box; padding: 0px 5px;">30</li><li style="box-sizing: border-box; padding: 0px 5px;">31</li><li style="box-sizing: border-box; padding: 0px 5px;">32</li></ul><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li><li style="box-sizing: border-box; padding: 0px 5px;">2</li><li style="box-sizing: border-box; padding: 0px 5px;">3</li><li style="box-sizing: border-box; padding: 0px 5px;">4</li><li style="box-sizing: border-box; padding: 0px 5px;">5</li><li style="box-sizing: border-box; padding: 0px 5px;">6</li><li style="box-sizing: border-box; padding: 0px 5px;">7</li><li style="box-sizing: border-box; padding: 0px 5px;">8</li><li style="box-sizing: border-box; padding: 0px 5px;">9</li><li style="box-sizing: border-box; padding: 0px 5px;">10</li><li style="box-sizing: border-box; padding: 0px 5px;">11</li><li style="box-sizing: border-box; padding: 0px 5px;">12</li><li style="box-sizing: border-box; padding: 0px 5px;">13</li><li style="box-sizing: border-box; padding: 0px 5px;">14</li><li style="box-sizing: border-box; padding: 0px 5px;">15</li><li style="box-sizing: border-box; padding: 0px 5px;">16</li><li style="box-sizing: border-box; padding: 0px 5px;">17</li><li style="box-sizing: border-box; padding: 0px 5px;">18</li><li style="box-sizing: border-box; padding: 0px 5px;">19</li><li style="box-sizing: border-box; padding: 0px 5px;">20</li><li style="box-sizing: border-box; padding: 0px 5px;">21</li><li style="box-sizing: border-box; padding: 0px 5px;">22</li><li style="box-sizing: border-box; padding: 0px 5px;">23</li><li style="box-sizing: border-box; padding: 0px 5px;">24</li><li style="box-sizing: border-box; padding: 0px 5px;">25</li><li style="box-sizing: border-box; padding: 0px 5px;">26</li><li style="box-sizing: border-box; padding: 0px 5px;">27</li><li style="box-sizing: border-box; padding: 0px 5px;">28</li><li style="box-sizing: border-box; padding: 0px 5px;">29</li><li style="box-sizing: border-box; padding: 0px 5px;">30</li><li style="box-sizing: border-box; padding: 0px 5px;">31</li><li style="box-sizing: border-box; padding: 0px 5px;">32</li></ul>

concatMap操作符

cancatMap操作符与flatMap操作符类似，都是把Observable产生的结果转换成多个Observable，然后把这多个Observable“扁平化”成一个Observable，并依次提交产生的结果给订阅者。
与flatMap操作符不同的是，concatMap操作符在处理产生的Observable时，采用的是“连接(concat)”的方式，而不是“合并(merge)”的方式，这就能保证产生结果的顺序性，也就是说提交给订阅者的结果是按照顺序提交的，不会存在交叉的情况。

switchMap操作符

switchMap操作符与flatMap操作符类似，都是把Observable产生的结果转换成多个Observable，然后把这多个Observable“扁平化”成一个Observable，并依次提交产生的结果给订阅者。
与flatMap操作符不同的是，switchMap操作符会保存最新的Observable产生的结果而舍弃旧的结果，举个例子来说，比如源Observable产生A、B、C三个结果，通过switchMap的自定义映射规则，映射后应该会产生A1、A2、B1、B2、C1、C2，但是在产生B2的同时，C1已经产生了，这样最后的结果就变成A1、A2、B1、C1、C2，B2被舍弃掉了！

这里写图片描述

以下是flatMap、concatMap和switchMap的运行实例对比：

<code class="hljs cs has-numbering" style="display: block; padding: 0px; color: inherit; box-sizing: border-box; font-family: 'Source Code Pro', monospace;font-size:undefined; white-space: pre; border-radius: 0px; word-wrap: normal; background: transparent;">        <span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">//flatMap操作符的运行结果</span>
        Observable.just(<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">10</span>, <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">20</span>, <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">30</span>).flatMap(<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">new</span> Func1<Integer, Observable<Integer>>() {
            @Override
            <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">public</span> Observable<Integer> <span class="hljs-title" style="box-sizing: border-box;">call</span>(Integer integer) {
                <span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">//10的延迟执行时间为200毫秒、20和30的延迟执行时间为180毫秒</span>
                <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">int</span> delay = <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">200</span>;
                <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">if</span> (integer > <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">10</span>)
                    delay = <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">180</span>;

                <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">return</span> Observable.<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">from</span>(<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">new</span> Integer[]{integer, integer / <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">2</span>}).delay(delay, TimeUnit.MILLISECONDS);
            }
        }).observeOn(AndroidSchedulers.mainThread()).subscribe(<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">new</span> Action1<Integer>() {
            @Override
            <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">public</span> <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">void</span> <span class="hljs-title" style="box-sizing: border-box;">call</span>(Integer integer) {
                System.<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">out</span>.println(<span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">"flatMap Next:"</span> + integer);
            }
        });

        <span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">//concatMap操作符的运行结果</span>
        Observable.just(<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">10</span>, <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">20</span>, <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">30</span>).concatMap(<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">new</span> Func1<Integer, Observable<Integer>>() {
            @Override
            <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">public</span> Observable<Integer> <span class="hljs-title" style="box-sizing: border-box;">call</span>(Integer integer) {
                <span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">//10的延迟执行时间为200毫秒、20和30的延迟执行时间为180毫秒</span>
                <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">int</span> delay = <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">200</span>;
                <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">if</span> (integer > <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">10</span>)
                    delay = <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">180</span>;

                <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">return</span> Observable.<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">from</span>(<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">new</span> Integer[]{integer, integer / <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">2</span>}).delay(delay, TimeUnit.MILLISECONDS);
            }
        }).observeOn(AndroidSchedulers.mainThread()).subscribe(<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">new</span> Action1<Integer>() {
            @Override
            <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">public</span> <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">void</span> <span class="hljs-title" style="box-sizing: border-box;">call</span>(Integer integer) {
                System.<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">out</span>.println(<span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">"concatMap Next:"</span> + integer);
            }
        });

        <span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">//switchMap操作符的运行结果</span>
        Observable.just(<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">10</span>, <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">20</span>, <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">30</span>).switchMap(<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">new</span> Func1<Integer, Observable<Integer>>() {
            @Override
            <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">public</span> Observable<Integer> <span class="hljs-title" style="box-sizing: border-box;">call</span>(Integer integer) {
                <span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">//10的延迟执行时间为200毫秒、20和30的延迟执行时间为180毫秒</span>
                <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">int</span> delay = <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">200</span>;
                <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">if</span> (integer > <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">10</span>)
                    delay = <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">180</span>;

                <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">return</span> Observable.<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">from</span>(<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">new</span> Integer[]{integer, integer / <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">2</span>}).delay(delay, TimeUnit.MILLISECONDS);
            }
        }).observeOn(AndroidSchedulers.mainThread()).subscribe(<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">new</span> Action1<Integer>() {
            @Override
            <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">public</span> <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">void</span> <span class="hljs-title" style="box-sizing: border-box;">call</span>(Integer integer) {
                System.<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">out</span>.println(<span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">"switchMap Next:"</span> + integer);
            }
        });
</code><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li><li style="box-sizing: border-box; padding: 0px 5px;">2</li><li style="box-sizing: border-box; padding: 0px 5px;">3</li><li style="box-sizing: border-box; padding: 0px 5px;">4</li><li style="box-sizing: border-box; padding: 0px 5px;">5</li><li style="box-sizing: border-box; padding: 0px 5px;">6</li><li style="box-sizing: border-box; padding: 0px 5px;">7</li><li style="box-sizing: border-box; padding: 0px 5px;">8</li><li style="box-sizing: border-box; padding: 0px 5px;">9</li><li style="box-sizing: border-box; padding: 0px 5px;">10</li><li style="box-sizing: border-box; padding: 0px 5px;">11</li><li style="box-sizing: border-box; padding: 0px 5px;">12</li><li style="box-sizing: border-box; padding: 0px 5px;">13</li><li style="box-sizing: border-box; padding: 0px 5px;">14</li><li style="box-sizing: border-box; padding: 0px 5px;">15</li><li style="box-sizing: border-box; padding: 0px 5px;">16</li><li style="box-sizing: border-box; padding: 0px 5px;">17</li><li style="box-sizing: border-box; padding: 0px 5px;">18</li><li style="box-sizing: border-box; padding: 0px 5px;">19</li><li style="box-sizing: border-box; padding: 0px 5px;">20</li><li style="box-sizing: border-box; padding: 0px 5px;">21</li><li style="box-sizing: border-box; padding: 0px 5px;">22</li><li style="box-sizing: border-box; padding: 0px 5px;">23</li><li style="box-sizing: border-box; padding: 0px 5px;">24</li><li style="box-sizing: border-box; padding: 0px 5px;">25</li><li style="box-sizing: border-box; padding: 0px 5px;">26</li><li style="box-sizing: border-box; padding: 0px 5px;">27</li><li style="box-sizing: border-box; padding: 0px 5px;">28</li><li style="box-sizing: border-box; padding: 0px 5px;">29</li><li style="box-sizing: border-box; padding: 0px 5px;">30</li><li style="box-sizing: border-box; padding: 0px 5px;">31</li><li style="box-sizing: border-box; padding: 0px 5px;">32</li><li style="box-sizing: border-box; padding: 0px 5px;">33</li><li style="box-sizing: border-box; padding: 0px 5px;">34</li><li style="box-sizing: border-box; padding: 0px 5px;">35</li><li style="box-sizing: border-box; padding: 0px 5px;">36</li><li style="box-sizing: border-box; padding: 0px 5px;">37</li><li style="box-sizing: border-box; padding: 0px 5px;">38</li><li style="box-sizing: border-box; padding: 0px 5px;">39</li><li style="box-sizing: border-box; padding: 0px 5px;">40</li><li style="box-sizing: border-box; padding: 0px 5px;">41</li><li style="box-sizing: border-box; padding: 0px 5px;">42</li><li style="box-sizing: border-box; padding: 0px 5px;">43</li><li style="box-sizing: border-box; padding: 0px 5px;">44</li><li style="box-sizing: border-box; padding: 0px 5px;">45</li><li style="box-sizing: border-box; padding: 0px 5px;">46</li><li style="box-sizing: border-box; padding: 0px 5px;">47</li><li style="box-sizing: border-box; padding: 0px 5px;">48</li><li style="box-sizing: border-box; padding: 0px 5px;">49</li><li style="box-sizing: border-box; padding: 0px 5px;">50</li><li style="box-sizing: border-box; padding: 0px 5px;">51</li><li style="box-sizing: border-box; padding: 0px 5px;">52</li><li style="box-sizing: border-box; padding: 0px 5px;">53</li><li style="box-sizing: border-box; padding: 0px 5px;">54</li></ul><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li><li style="box-sizing: border-box; padding: 0px 5px;">2</li><li style="box-sizing: border-box; padding: 0px 5px;">3</li><li style="box-sizing: border-box; padding: 0px 5px;">4</li><li style="box-sizing: border-box; padding: 0px 5px;">5</li><li style="box-sizing: border-box; padding: 0px 5px;">6</li><li style="box-sizing: border-box; padding: 0px 5px;">7</li><li style="box-sizing: border-box; padding: 0px 5px;">8</li><li style="box-sizing: border-box; padding: 0px 5px;">9</li><li style="box-sizing: border-box; padding: 0px 5px;">10</li><li style="box-sizing: border-box; padding: 0px 5px;">11</li><li style="box-sizing: border-box; padding: 0px 5px;">12</li><li style="box-sizing: border-box; padding: 0px 5px;">13</li><li style="box-sizing: border-box; padding: 0px 5px;">14</li><li style="box-sizing: border-box; padding: 0px 5px;">15</li><li style="box-sizing: border-box; padding: 0px 5px;">16</li><li style="box-sizing: border-box; padding: 0px 5px;">17</li><li style="box-sizing: border-box; padding: 0px 5px;">18</li><li style="box-sizing: border-box; padding: 0px 5px;">19</li><li style="box-sizing: border-box; padding: 0px 5px;">20</li><li style="box-sizing: border-box; padding: 0px 5px;">21</li><li style="box-sizing: border-box; padding: 0px 5px;">22</li><li style="box-sizing: border-box; padding: 0px 5px;">23</li><li style="box-sizing: border-box; padding: 0px 5px;">24</li><li style="box-sizing: border-box; padding: 0px 5px;">25</li><li style="box-sizing: border-box; padding: 0px 5px;">26</li><li style="box-sizing: border-box; padding: 0px 5px;">27</li><li style="box-sizing: border-box; padding: 0px 5px;">28</li><li style="box-sizing: border-box; padding: 0px 5px;">29</li><li style="box-sizing: border-box; padding: 0px 5px;">30</li><li style="box-sizing: border-box; padding: 0px 5px;">31</li><li style="box-sizing: border-box; padding: 0px 5px;">32</li><li style="box-sizing: border-box; padding: 0px 5px;">33</li><li style="box-sizing: border-box; padding: 0px 5px;">34</li><li style="box-sizing: border-box; padding: 0px 5px;">35</li><li style="box-sizing: border-box; padding: 0px 5px;">36</li><li style="box-sizing: border-box; padding: 0px 5px;">37</li><li style="box-sizing: border-box; padding: 0px 5px;">38</li><li style="box-sizing: border-box; padding: 0px 5px;">39</li><li style="box-sizing: border-box; padding: 0px 5px;">40</li><li style="box-sizing: border-box; padding: 0px 5px;">41</li><li style="box-sizing: border-box; padding: 0px 5px;">42</li><li style="box-sizing: border-box; padding: 0px 5px;">43</li><li style="box-sizing: border-box; padding: 0px 5px;">44</li><li style="box-sizing: border-box; padding: 0px 5px;">45</li><li style="box-sizing: border-box; padding: 0px 5px;">46</li><li style="box-sizing: border-box; padding: 0px 5px;">47</li><li style="box-sizing: border-box; padding: 0px 5px;">48</li><li style="box-sizing: border-box; padding: 0px 5px;">49</li><li style="box-sizing: border-box; padding: 0px 5px;">50</li><li style="box-sizing: border-box; padding: 0px 5px;">51</li><li style="box-sizing: border-box; padding: 0px 5px;">52</li><li style="box-sizing: border-box; padding: 0px 5px;">53</li><li style="box-sizing: border-box; padding: 0px 5px;">54</li></ul>

<code class="hljs css has-numbering" style="display: block; padding: 0px; color: inherit; box-sizing: border-box; font-family: 'Source Code Pro', monospace;font-size:undefined; white-space: pre; border-radius: 0px; word-wrap: normal; background: transparent;">运行结果如下：
<span class="hljs-tag" style="color: rgb(0, 0, 0); box-sizing: border-box;">flatMap</span> <span class="hljs-tag" style="color: rgb(0, 0, 0); box-sizing: border-box;">Next</span><span class="hljs-pseudo" style="color: rgb(0, 0, 0); box-sizing: border-box;">:20</span>
<span class="hljs-tag" style="color: rgb(0, 0, 0); box-sizing: border-box;">flatMap</span> <span class="hljs-tag" style="color: rgb(0, 0, 0); box-sizing: border-box;">Next</span><span class="hljs-pseudo" style="color: rgb(0, 0, 0); box-sizing: border-box;">:10</span>
<span class="hljs-tag" style="color: rgb(0, 0, 0); box-sizing: border-box;">flatMap</span> <span class="hljs-tag" style="color: rgb(0, 0, 0); box-sizing: border-box;">Next</span><span class="hljs-pseudo" style="color: rgb(0, 0, 0); box-sizing: border-box;">:30</span>
<span class="hljs-tag" style="color: rgb(0, 0, 0); box-sizing: border-box;">flatMap</span> <span class="hljs-tag" style="color: rgb(0, 0, 0); box-sizing: border-box;">Next</span><span class="hljs-pseudo" style="color: rgb(0, 0, 0); box-sizing: border-box;">:15</span>
<span class="hljs-tag" style="color: rgb(0, 0, 0); box-sizing: border-box;">flatMap</span> <span class="hljs-tag" style="color: rgb(0, 0, 0); box-sizing: border-box;">Next</span><span class="hljs-pseudo" style="color: rgb(0, 0, 0); box-sizing: border-box;">:10</span>
<span class="hljs-tag" style="color: rgb(0, 0, 0); box-sizing: border-box;">flatMap</span> <span class="hljs-tag" style="color: rgb(0, 0, 0); box-sizing: border-box;">Next</span><span class="hljs-pseudo" style="color: rgb(0, 0, 0); box-sizing: border-box;">:5</span>

<span class="hljs-tag" style="color: rgb(0, 0, 0); box-sizing: border-box;">switchMap</span> <span class="hljs-tag" style="color: rgb(0, 0, 0); box-sizing: border-box;">Next</span><span class="hljs-pseudo" style="color: rgb(0, 0, 0); box-sizing: border-box;">:30</span>
<span class="hljs-tag" style="color: rgb(0, 0, 0); box-sizing: border-box;">switchMap</span> <span class="hljs-tag" style="color: rgb(0, 0, 0); box-sizing: border-box;">Next</span><span class="hljs-pseudo" style="color: rgb(0, 0, 0); box-sizing: border-box;">:15</span>

<span class="hljs-tag" style="color: rgb(0, 0, 0); box-sizing: border-box;">concatMap</span> <span class="hljs-tag" style="color: rgb(0, 0, 0); box-sizing: border-box;">Next</span><span class="hljs-pseudo" style="color: rgb(0, 0, 0); box-sizing: border-box;">:10</span>
<span class="hljs-tag" style="color: rgb(0, 0, 0); box-sizing: border-box;">concatMap</span> <span class="hljs-tag" style="color: rgb(0, 0, 0); box-sizing: border-box;">Next</span><span class="hljs-pseudo" style="color: rgb(0, 0, 0); box-sizing: border-box;">:5</span>
<span class="hljs-tag" style="color: rgb(0, 0, 0); box-sizing: border-box;">concatMap</span> <span class="hljs-tag" style="color: rgb(0, 0, 0); box-sizing: border-box;">Next</span><span class="hljs-pseudo" style="color: rgb(0, 0, 0); box-sizing: border-box;">:20</span>
<span class="hljs-tag" style="color: rgb(0, 0, 0); box-sizing: border-box;">concatMap</span> <span class="hljs-tag" style="color: rgb(0, 0, 0); box-sizing: border-box;">Next</span><span class="hljs-pseudo" style="color: rgb(0, 0, 0); box-sizing: border-box;">:10</span>
<span class="hljs-tag" style="color: rgb(0, 0, 0); box-sizing: border-box;">concatMap</span> <span class="hljs-tag" style="color: rgb(0, 0, 0); box-sizing: border-box;">Next</span><span class="hljs-pseudo" style="color: rgb(0, 0, 0); box-sizing: border-box;">:30</span>
<span class="hljs-tag" style="color: rgb(0, 0, 0); box-sizing: border-box;">concatMap</span> <span class="hljs-tag" style="color: rgb(0, 0, 0); box-sizing: border-box;">Next</span><span class="hljs-pseudo" style="color: rgb(0, 0, 0); box-sizing: border-box;">:15</span></code><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li><li style="box-sizing: border-box; padding: 0px 5px;">2</li><li style="box-sizing: border-box; padding: 0px 5px;">3</li><li style="box-sizing: border-box; padding: 0px 5px;">4</li><li style="box-sizing: border-box; padding: 0px 5px;">5</li><li style="box-sizing: border-box; padding: 0px 5px;">6</li><li style="box-sizing: border-box; padding: 0px 5px;">7</li><li style="box-sizing: border-box; padding: 0px 5px;">8</li><li style="box-sizing: border-box; padding: 0px 5px;">9</li><li style="box-sizing: border-box; padding: 0px 5px;">10</li><li style="box-sizing: border-box; padding: 0px 5px;">11</li><li style="box-sizing: border-box; padding: 0px 5px;">12</li><li style="box-sizing: border-box; padding: 0px 5px;">13</li><li style="box-sizing: border-box; padding: 0px 5px;">14</li><li style="box-sizing: border-box; padding: 0px 5px;">15</li><li style="box-sizing: border-box; padding: 0px 5px;">16</li><li style="box-sizing: border-box; padding: 0px 5px;">17</li></ul><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li><li style="box-sizing: border-box; padding: 0px 5px;">2</li><li style="box-sizing: border-box; padding: 0px 5px;">3</li><li style="box-sizing: border-box; padding: 0px 5px;">4</li><li style="box-sizing: border-box; padding: 0px 5px;">5</li><li style="box-sizing: border-box; padding: 0px 5px;">6</li><li style="box-sizing: border-box; padding: 0px 5px;">7</li><li style="box-sizing: border-box; padding: 0px 5px;">8</li><li style="box-sizing: border-box; padding: 0px 5px;">9</li><li style="box-sizing: border-box; padding: 0px 5px;">10</li><li style="box-sizing: border-box; padding: 0px 5px;">11</li><li style="box-sizing: border-box; padding: 0px 5px;">12</li><li style="box-sizing: border-box; padding: 0px 5px;">13</li><li style="box-sizing: border-box; padding: 0px 5px;">14</li><li style="box-sizing: border-box; padding: 0px 5px;">15</li><li style="box-sizing: border-box; padding: 0px 5px;">16</li><li style="box-sizing: border-box; padding: 0px 5px;">17</li></ul>

groupBy操作符

groupBy操作符是对源Observable产生的结果进行分组，形成一个类型为GroupedObservable的结果集，GroupedObservable中存在一个方法为getKey()，可以通过该方法获取结果集的Key值（类似于HashMap的key)。
值得注意的是，由于结果集中的GroupedObservable是把分组结果缓存起来，如果对每一个GroupedObservable不进行处理（既不订阅执行也不对其进行别的操作符运算），就有可能出现内存泄露。因此，如果你对某个GroupedObservable不进行处理，最好是对其使用操作符take(0)处理。

groupBy操作符的流程图如下

调用例子如下：

<code class="hljs cs has-numbering" style="display: block; padding: 0px; color: inherit; box-sizing: border-box; font-family: 'Source Code Pro', monospace;font-size:undefined; white-space: pre; border-radius: 0px; word-wrap: normal; background: transparent;">Observable.interval(<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span>, TimeUnit.SECONDS).take(<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">10</span>).groupBy(<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">new</span> Func1<Long, Long>() {
            @Override
            <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">public</span> Long <span class="hljs-title" style="box-sizing: border-box;">call</span>(Long <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">value</span>) {
                <span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">//按照key为0,1,2分为3组</span>
                <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">return</span> <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">value</span> % <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">3</span>;
            }
        }).subscribe(<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">new</span> Action1<GroupedObservable<Long, Long>>() {
            @Override
            <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">public</span> <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">void</span> <span class="hljs-title" style="box-sizing: border-box;">call</span>(GroupedObservable<Long, Long> result) {
                result.subscribe(<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">new</span> Action1<Long>() {
                    @Override
                    <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">public</span> <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">void</span> <span class="hljs-title" style="box-sizing: border-box;">call</span>(Long <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">value</span>) {
                        System.<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">out</span>.println(<span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">"key:"</span> + result.getKey() +<span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">", value:"</span> + <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">value</span>);
                    }
                });
            }
        });</code><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li><li style="box-sizing: border-box; padding: 0px 5px;">2</li><li style="box-sizing: border-box; padding: 0px 5px;">3</li><li style="box-sizing: border-box; padding: 0px 5px;">4</li><li style="box-sizing: border-box; padding: 0px 5px;">5</li><li style="box-sizing: border-box; padding: 0px 5px;">6</li><li style="box-sizing: border-box; padding: 0px 5px;">7</li><li style="box-sizing: border-box; padding: 0px 5px;">8</li><li style="box-sizing: border-box; padding: 0px 5px;">9</li><li style="box-sizing: border-box; padding: 0px 5px;">10</li><li style="box-sizing: border-box; padding: 0px 5px;">11</li><li style="box-sizing: border-box; padding: 0px 5px;">12</li><li style="box-sizing: border-box; padding: 0px 5px;">13</li><li style="box-sizing: border-box; padding: 0px 5px;">14</li><li style="box-sizing: border-box; padding: 0px 5px;">15</li><li style="box-sizing: border-box; padding: 0px 5px;">16</li><li style="box-sizing: border-box; padding: 0px 5px;">17</li></ul><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li><li style="box-sizing: border-box; padding: 0px 5px;">2</li><li style="box-sizing: border-box; padding: 0px 5px;">3</li><li style="box-sizing: border-box; padding: 0px 5px;">4</li><li style="box-sizing: border-box; padding: 0px 5px;">5</li><li style="box-sizing: border-box; padding: 0px 5px;">6</li><li style="box-sizing: border-box; padding: 0px 5px;">7</li><li style="box-sizing: border-box; padding: 0px 5px;">8</li><li style="box-sizing: border-box; padding: 0px 5px;">9</li><li style="box-sizing: border-box; padding: 0px 5px;">10</li><li style="box-sizing: border-box; padding: 0px 5px;">11</li><li style="box-sizing: border-box; padding: 0px 5px;">12</li><li style="box-sizing: border-box; padding: 0px 5px;">13</li><li style="box-sizing: border-box; padding: 0px 5px;">14</li><li style="box-sizing: border-box; padding: 0px 5px;">15</li><li style="box-sizing: border-box; padding: 0px 5px;">16</li><li style="box-sizing: border-box; padding: 0px 5px;">17</li></ul>

<code class="hljs css has-numbering" style="display: block; padding: 0px; color: inherit; box-sizing: border-box; font-family: 'Source Code Pro', monospace;font-size:undefined; white-space: pre; border-radius: 0px; word-wrap: normal; background: transparent;">运行结果如下：
<span class="hljs-tag" style="color: rgb(0, 0, 0); box-sizing: border-box;">key</span><span class="hljs-pseudo" style="color: rgb(0, 0, 0); box-sizing: border-box;">:0</span>, <span class="hljs-tag" style="color: rgb(0, 0, 0); box-sizing: border-box;">value</span><span class="hljs-pseudo" style="color: rgb(0, 0, 0); box-sizing: border-box;">:0</span>
<span class="hljs-tag" style="color: rgb(0, 0, 0); box-sizing: border-box;">key</span><span class="hljs-pseudo" style="color: rgb(0, 0, 0); box-sizing: border-box;">:1</span>, <span class="hljs-tag" style="color: rgb(0, 0, 0); box-sizing: border-box;">value</span><span class="hljs-pseudo" style="color: rgb(0, 0, 0); box-sizing: border-box;">:1</span>
<span class="hljs-tag" style="color: rgb(0, 0, 0); box-sizing: border-box;">key</span><span class="hljs-pseudo" style="color: rgb(0, 0, 0); box-sizing: border-box;">:2</span>, <span class="hljs-tag" style="color: rgb(0, 0, 0); box-sizing: border-box;">value</span><span class="hljs-pseudo" style="color: rgb(0, 0, 0); box-sizing: border-box;">:2</span>
<span class="hljs-tag" style="color: rgb(0, 0, 0); box-sizing: border-box;">key</span><span class="hljs-pseudo" style="color: rgb(0, 0, 0); box-sizing: border-box;">:0</span>, <span class="hljs-tag" style="color: rgb(0, 0, 0); box-sizing: border-box;">value</span><span class="hljs-pseudo" style="color: rgb(0, 0, 0); box-sizing: border-box;">:3</span>
<span class="hljs-tag" style="color: rgb(0, 0, 0); box-sizing: border-box;">key</span><span class="hljs-pseudo" style="color: rgb(0, 0, 0); box-sizing: border-box;">:1</span>, <span class="hljs-tag" style="color: rgb(0, 0, 0); box-sizing: border-box;">value</span><span class="hljs-pseudo" style="color: rgb(0, 0, 0); box-sizing: border-box;">:4</span>
<span class="hljs-tag" style="color: rgb(0, 0, 0); box-sizing: border-box;">key</span><span class="hljs-pseudo" style="color: rgb(0, 0, 0); box-sizing: border-box;">:2</span>, <span class="hljs-tag" style="color: rgb(0, 0, 0); box-sizing: border-box;">value</span><span class="hljs-pseudo" style="color: rgb(0, 0, 0); box-sizing: border-box;">:5</span>
<span class="hljs-tag" style="color: rgb(0, 0, 0); box-sizing: border-box;">key</span><span class="hljs-pseudo" style="color: rgb(0, 0, 0); box-sizing: border-box;">:0</span>, <span class="hljs-tag" style="color: rgb(0, 0, 0); box-sizing: border-box;">value</span><span class="hljs-pseudo" style="color: rgb(0, 0, 0); box-sizing: border-box;">:6</span>
<span class="hljs-tag" style="color: rgb(0, 0, 0); box-sizing: border-box;">key</span><span class="hljs-pseudo" style="color: rgb(0, 0, 0); box-sizing: border-box;">:1</span>, <span class="hljs-tag" style="color: rgb(0, 0, 0); box-sizing: border-box;">value</span><span class="hljs-pseudo" style="color: rgb(0, 0, 0); box-sizing: border-box;">:7</span>
<span class="hljs-tag" style="color: rgb(0, 0, 0); box-sizing: border-box;">key</span><span class="hljs-pseudo" style="color: rgb(0, 0, 0); box-sizing: border-box;">:2</span>, <span class="hljs-tag" style="color: rgb(0, 0, 0); box-sizing: border-box;">value</span><span class="hljs-pseudo" style="color: rgb(0, 0, 0); box-sizing: border-box;">:8</span>
<span class="hljs-tag" style="color: rgb(0, 0, 0); box-sizing: border-box;">key</span><span class="hljs-pseudo" style="color: rgb(0, 0, 0); box-sizing: border-box;">:0</span>, <span class="hljs-tag" style="color: rgb(0, 0, 0); box-sizing: border-box;">value</span><span class="hljs-pseudo" style="color: rgb(0, 0, 0); box-sizing: border-box;">:9</span></code><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li><li style="box-sizing: border-box; padding: 0px 5px;">2</li><li style="box-sizing: border-box; padding: 0px 5px;">3</li><li style="box-sizing: border-box; padding: 0px 5px;">4</li><li style="box-sizing: border-box; padding: 0px 5px;">5</li><li style="box-sizing: border-box; padding: 0px 5px;">6</li><li style="box-sizing: border-box; padding: 0px 5px;">7</li><li style="box-sizing: border-box; padding: 0px 5px;">8</li><li style="box-sizing: border-box; padding: 0px 5px;">9</li><li style="box-sizing: border-box; padding: 0px 5px;">10</li><li style="box-sizing: border-box; padding: 0px 5px;">11</li></ul><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li><li style="box-sizing: border-box; padding: 0px 5px;">2</li><li style="box-sizing: border-box; padding: 0px 5px;">3</li><li style="box-sizing: border-box; padding: 0px 5px;">4</li><li style="box-sizing: border-box; padding: 0px 5px;">5</li><li style="box-sizing: border-box; padding: 0px 5px;">6</li><li style="box-sizing: border-box; padding: 0px 5px;">7</li><li style="box-sizing: border-box; padding: 0px 5px;">8</li><li style="box-sizing: border-box; padding: 0px 5px;">9</li><li style="box-sizing: border-box; padding: 0px 5px;">10</li><li style="box-sizing: border-box; padding: 0px 5px;">11</li></ul>

map操作符

map操作符是把源Observable产生的结果，通过映射规则转换成另一个结果集，并提交给订阅者进行处理。

<code class="hljs lasso has-numbering" style="display: block; padding: 0px; color: inherit; box-sizing: border-box; font-family: 'Source Code Pro', monospace;font-size:undefined; white-space: pre; border-radius: 0px; word-wrap: normal; background: transparent;">Observable<span class="hljs-built_in" style="color: rgb(102, 0, 102); box-sizing: border-box;">.</span>just(<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span>,<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">2</span>,<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">3</span>,<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">4</span>,<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">5</span>,<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">6</span>)<span class="hljs-built_in" style="color: rgb(102, 0, 102); box-sizing: border-box;">.</span><span class="hljs-built_in" style="color: rgb(102, 0, 102); box-sizing: border-box;">map</span>(<span class="hljs-literal" style="color: rgb(0, 102, 102); box-sizing: border-box;">new</span> Func1<span class="hljs-subst" style="color: rgb(0, 0, 0); box-sizing: border-box;"><</span><span class="hljs-built_in" style="color: rgb(102, 0, 102); box-sizing: border-box;">Integer</span>, <span class="hljs-built_in" style="color: rgb(102, 0, 102); box-sizing: border-box;">Integer</span><span class="hljs-subst" style="color: rgb(0, 0, 0); box-sizing: border-box;">></span>() {
            @Override
            <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">public</span> <span class="hljs-built_in" style="color: rgb(102, 0, 102); box-sizing: border-box;">Integer</span> call(<span class="hljs-built_in" style="color: rgb(102, 0, 102); box-sizing: border-box;">Integer</span> <span class="hljs-built_in" style="color: rgb(102, 0, 102); box-sizing: border-box;">integer</span>) {
                <span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">//对源Observable产生的结果，都统一乘以3处理</span>
                <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">return</span> <span class="hljs-built_in" style="color: rgb(102, 0, 102); box-sizing: border-box;">integer</span><span class="hljs-subst" style="color: rgb(0, 0, 0); box-sizing: border-box;">*</span><span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">3</span>;
            }
        })<span class="hljs-built_in" style="color: rgb(102, 0, 102); box-sizing: border-box;">.</span>subscribe(<span class="hljs-literal" style="color: rgb(0, 102, 102); box-sizing: border-box;">new</span> Action1<span class="hljs-subst" style="color: rgb(0, 0, 0); box-sizing: border-box;"><</span><span class="hljs-built_in" style="color: rgb(102, 0, 102); box-sizing: border-box;">Integer</span><span class="hljs-subst" style="color: rgb(0, 0, 0); box-sizing: border-box;">></span>() {
            @Override
            <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">public</span> <span class="hljs-literal" style="color: rgb(0, 102, 102); box-sizing: border-box;">void</span> call(<span class="hljs-built_in" style="color: rgb(102, 0, 102); box-sizing: border-box;">Integer</span> <span class="hljs-built_in" style="color: rgb(102, 0, 102); box-sizing: border-box;">integer</span>) {
                System<span class="hljs-built_in" style="color: rgb(102, 0, 102); box-sizing: border-box;">.</span>out<span class="hljs-built_in" style="color: rgb(102, 0, 102); box-sizing: border-box;">.</span>println(<span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">"next:"</span> <span class="hljs-subst" style="color: rgb(0, 0, 0); box-sizing: border-box;">+</span> <span class="hljs-built_in" style="color: rgb(102, 0, 102); box-sizing: border-box;">integer</span>);
            }
        });</code><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li><li style="box-sizing: border-box; padding: 0px 5px;">2</li><li style="box-sizing: border-box; padding: 0px 5px;">3</li><li style="box-sizing: border-box; padding: 0px 5px;">4</li><li style="box-sizing: border-box; padding: 0px 5px;">5</li><li style="box-sizing: border-box; padding: 0px 5px;">6</li><li style="box-sizing: border-box; padding: 0px 5px;">7</li><li style="box-sizing: border-box; padding: 0px 5px;">8</li><li style="box-sizing: border-box; padding: 0px 5px;">9</li><li style="box-sizing: border-box; padding: 0px 5px;">10</li><li style="box-sizing: border-box; padding: 0px 5px;">11</li><li style="box-sizing: border-box; padding: 0px 5px;">12</li></ul><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li><li style="box-sizing: border-box; padding: 0px 5px;">2</li><li style="box-sizing: border-box; padding: 0px 5px;">3</li><li style="box-sizing: border-box; padding: 0px 5px;">4</li><li style="box-sizing: border-box; padding: 0px 5px;">5</li><li style="box-sizing: border-box; padding: 0px 5px;">6</li><li style="box-sizing: border-box; padding: 0px 5px;">7</li><li style="box-sizing: border-box; padding: 0px 5px;">8</li><li style="box-sizing: border-box; padding: 0px 5px;">9</li><li style="box-sizing: border-box; padding: 0px 5px;">10</li><li style="box-sizing: border-box; padding: 0px 5px;">11</li><li style="box-sizing: border-box; padding: 0px 5px;">12</li></ul>

<code class="hljs lua has-numbering" style="display: block; padding: 0px; color: inherit; box-sizing: border-box; font-family: 'Source Code Pro', monospace;font-size:undefined; white-space: pre; border-radius: 0px; word-wrap: normal; background: transparent;">运行结果如下：
<span class="hljs-built_in" style="color: rgb(102, 0, 102); box-sizing: border-box;">next</span>:<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">3</span>
<span class="hljs-built_in" style="color: rgb(102, 0, 102); box-sizing: border-box;">next</span>:<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">6</span>
<span class="hljs-built_in" style="color: rgb(102, 0, 102); box-sizing: border-box;">next</span>:<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">9</span>
<span class="hljs-built_in" style="color: rgb(102, 0, 102); box-sizing: border-box;">next</span>:<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">12</span>
<span class="hljs-built_in" style="color: rgb(102, 0, 102); box-sizing: border-box;">next</span>:<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">15</span>
<span class="hljs-built_in" style="color: rgb(102, 0, 102); box-sizing: border-box;">next</span>:<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">18</span></code><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li><li style="box-sizing: border-box; padding: 0px 5px;">2</li><li style="box-sizing: border-box; padding: 0px 5px;">3</li><li style="box-sizing: border-box; padding: 0px 5px;">4</li><li style="box-sizing: border-box; padding: 0px 5px;">5</li><li style="box-sizing: border-box; padding: 0px 5px;">6</li><li style="box-sizing: border-box; padding: 0px 5px;">7</li></ul><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li><li style="box-sizing: border-box; padding: 0px 5px;">2</li><li style="box-sizing: border-box; padding: 0px 5px;">3</li><li style="box-sizing: border-box; padding: 0px 5px;">4</li><li style="box-sizing: border-box; padding: 0px 5px;">5</li><li style="box-sizing: border-box; padding: 0px 5px;">6</li><li style="box-sizing: border-box; padding: 0px 5px;">7</li></ul>

cast操作符

cast操作符类似于map操作符，不同的地方在于map操作符可以通过自定义规则，把一个值A1变成另一个值A2，A1和A2的类型可以一样也可以不一样；而cast操作符主要是做类型转换的，传入参数为类型class，如果源Observable产生的结果不能转成指定的class，则会抛出ClassCastException运行时异常。

这里写图片描述

<code class="hljs cs has-numbering" style="display: block; padding: 0px; color: inherit; box-sizing: border-box; font-family: 'Source Code Pro', monospace;font-size:undefined; white-space: pre; border-radius: 0px; word-wrap: normal; background: transparent;">        Observable.just(<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span>,<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">2</span>,<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">3</span>,<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">4</span>,<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">5</span>,<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">6</span>).cast(Integer.class).subscribe(<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">new</span> Action1<Integer>() {
            @Override
            <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">public</span> <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">void</span> <span class="hljs-title" style="box-sizing: border-box;">call</span>(Integer <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">value</span>) {
                System.<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">out</span>.println(<span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">"next:"</span>+<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">value</span>);
            }
        });</code><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li><li style="box-sizing: border-box; padding: 0px 5px;">2</li><li style="box-sizing: border-box; padding: 0px 5px;">3</li><li style="box-sizing: border-box; padding: 0px 5px;">4</li><li style="box-sizing: border-box; padding: 0px 5px;">5</li><li style="box-sizing: border-box; padding: 0px 5px;">6</li></ul><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li><li style="box-sizing: border-box; padding: 0px 5px;">2</li><li style="box-sizing: border-box; padding: 0px 5px;">3</li><li style="box-sizing: border-box; padding: 0px 5px;">4</li><li style="box-sizing: border-box; padding: 0px 5px;">5</li><li style="box-sizing: border-box; padding: 0px 5px;">6</li></ul>

<code class="hljs lua has-numbering" style="display: block; padding: 0px; color: inherit; box-sizing: border-box; font-family: 'Source Code Pro', monospace;font-size:undefined; white-space: pre; border-radius: 0px; word-wrap: normal; background: transparent;">运行结果如下：
<span class="hljs-built_in" style="color: rgb(102, 0, 102); box-sizing: border-box;">next</span>:<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span>
<span class="hljs-built_in" style="color: rgb(102, 0, 102); box-sizing: border-box;">next</span>:<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">2</span>
<span class="hljs-built_in" style="color: rgb(102, 0, 102); box-sizing: border-box;">next</span>:<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">3</span>
<span class="hljs-built_in" style="color: rgb(102, 0, 102); box-sizing: border-box;">next</span>:<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">4</span>
<span class="hljs-built_in" style="color: rgb(102, 0, 102); box-sizing: border-box;">next</span>:<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">5</span>
<span class="hljs-built_in" style="color: rgb(102, 0, 102); box-sizing: border-box;">next</span>:<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">6</span></code><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li><li style="box-sizing: border-box; padding: 0px 5px;">2</li><li style="box-sizing: border-box; padding: 0px 5px;">3</li><li style="box-sizing: border-box; padding: 0px 5px;">4</li><li style="box-sizing: border-box; padding: 0px 5px;">5</li><li style="box-sizing: border-box; padding: 0px 5px;">6</li><li style="box-sizing: border-box; padding: 0px 5px;">7</li></ul><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li><li style="box-sizing: border-box; padding: 0px 5px;">2</li><li style="box-sizing: border-box; padding: 0px 5px;">3</li><li style="box-sizing: border-box; padding: 0px 5px;">4</li><li style="box-sizing: border-box; padding: 0px 5px;">5</li><li style="box-sizing: border-box; padding: 0px 5px;">6</li><li style="box-sizing: border-box; padding: 0px 5px;">7</li></ul>

scan操作符

scan操作符通过遍历源Observable产生的结果，依次对每一个结果项按照指定规则进行运算，计算后的结果作为下一个迭代项参数，每一次迭代项都会把计算结果输出给订阅者。

<code class="hljs java has-numbering" style="display: block; padding: 0px; color: inherit; box-sizing: border-box; font-family: 'Source Code Pro', monospace;font-size:undefined; white-space: pre; border-radius: 0px; word-wrap: normal; background: transparent;">Observable.just(<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span>, <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">2</span>, <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">3</span>, <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">4</span>, <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">5</span>)
    .scan(<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">new</span> Func2<Integer, Integer, Integer>() {
        <span class="hljs-annotation" style="color: rgb(155, 133, 157); box-sizing: border-box;">@Override</span>
        <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">public</span> Integer <span class="hljs-title" style="box-sizing: border-box;">call</span>(Integer sum, Integer item) {
            <span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">//参数sum就是上一次的计算结果</span>
            <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">return</span> sum + item;
        }
    }).subscribe(<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">new</span> Subscriber<Integer>() {
        <span class="hljs-annotation" style="color: rgb(155, 133, 157); box-sizing: border-box;">@Override</span>
        <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">public</span> <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">void</span> <span class="hljs-title" style="box-sizing: border-box;">onNext</span>(Integer item) {
            System.out.println(<span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">"Next: "</span> + item);
        }

        <span class="hljs-annotation" style="color: rgb(155, 133, 157); box-sizing: border-box;">@Override</span>
        <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">public</span> <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">void</span> <span class="hljs-title" style="box-sizing: border-box;">onError</span>(Throwable error) {
            System.err.println(<span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">"Error: "</span> + error.getMessage());
        }

        <span class="hljs-annotation" style="color: rgb(155, 133, 157); box-sizing: border-box;">@Override</span>
        <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">public</span> <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">void</span> <span class="hljs-title" style="box-sizing: border-box;">onCompleted</span>() {
            System.out.println(<span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">"Sequence complete."</span>);
        }
    });</code><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li><li style="box-sizing: border-box; padding: 0px 5px;">2</li><li style="box-sizing: border-box; padding: 0px 5px;">3</li><li style="box-sizing: border-box; padding: 0px 5px;">4</li><li style="box-sizing: border-box; padding: 0px 5px;">5</li><li style="box-sizing: border-box; padding: 0px 5px;">6</li><li style="box-sizing: border-box; padding: 0px 5px;">7</li><li style="box-sizing: border-box; padding: 0px 5px;">8</li><li style="box-sizing: border-box; padding: 0px 5px;">9</li><li style="box-sizing: border-box; padding: 0px 5px;">10</li><li style="box-sizing: border-box; padding: 0px 5px;">11</li><li style="box-sizing: border-box; padding: 0px 5px;">12</li><li style="box-sizing: border-box; padding: 0px 5px;">13</li><li style="box-sizing: border-box; padding: 0px 5px;">14</li><li style="box-sizing: border-box; padding: 0px 5px;">15</li><li style="box-sizing: border-box; padding: 0px 5px;">16</li><li style="box-sizing: border-box; padding: 0px 5px;">17</li><li style="box-sizing: border-box; padding: 0px 5px;">18</li><li style="box-sizing: border-box; padding: 0px 5px;">19</li><li style="box-sizing: border-box; padding: 0px 5px;">20</li><li style="box-sizing: border-box; padding: 0px 5px;">21</li><li style="box-sizing: border-box; padding: 0px 5px;">22</li><li style="box-sizing: border-box; padding: 0px 5px;">23</li></ul><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li><li style="box-sizing: border-box; padding: 0px 5px;">2</li><li style="box-sizing: border-box; padding: 0px 5px;">3</li><li style="box-sizing: border-box; padding: 0px 5px;">4</li><li style="box-sizing: border-box; padding: 0px 5px;">5</li><li style="box-sizing: border-box; padding: 0px 5px;">6</li><li style="box-sizing: border-box; padding: 0px 5px;">7</li><li style="box-sizing: border-box; padding: 0px 5px;">8</li><li style="box-sizing: border-box; padding: 0px 5px;">9</li><li style="box-sizing: border-box; padding: 0px 5px;">10</li><li style="box-sizing: border-box; padding: 0px 5px;">11</li><li style="box-sizing: border-box; padding: 0px 5px;">12</li><li style="box-sizing: border-box; padding: 0px 5px;">13</li><li style="box-sizing: border-box; padding: 0px 5px;">14</li><li style="box-sizing: border-box; padding: 0px 5px;">15</li><li style="box-sizing: border-box; padding: 0px 5px;">16</li><li style="box-sizing: border-box; padding: 0px 5px;">17</li><li style="box-sizing: border-box; padding: 0px 5px;">18</li><li style="box-sizing: border-box; padding: 0px 5px;">19</li><li style="box-sizing: border-box; padding: 0px 5px;">20</li><li style="box-sizing: border-box; padding: 0px 5px;">21</li><li style="box-sizing: border-box; padding: 0px 5px;">22</li><li style="box-sizing: border-box; padding: 0px 5px;">23</li></ul>

<code class="hljs mathematica has-numbering" style="display: block; padding: 0px; color: inherit; box-sizing: border-box; font-family: 'Source Code Pro', monospace;font-size:undefined; white-space: pre; border-radius: 0px; word-wrap: normal; background: transparent;">运行结果如下：
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">Next</span>: <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span>
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">Next</span>: <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">3</span>
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">Next</span>: <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">6</span>
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">Next</span>: <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">10</span>
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">Next</span>: <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">15</span>
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">Sequence</span> complete.</code><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li><li style="box-sizing: border-box; padding: 0px 5px;">2</li><li style="box-sizing: border-box; padding: 0px 5px;">3</li><li style="box-sizing: border-box; padding: 0px 5px;">4</li><li style="box-sizing: border-box; padding: 0px 5px;">5</li><li style="box-sizing: border-box; padding: 0px 5px;">6</li><li style="box-sizing: border-box; padding: 0px 5px;">7</li></ul><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li><li style="box-sizing: border-box; padding: 0px 5px;">2</li><li style="box-sizing: border-box; padding: 0px 5px;">3</li><li style="box-sizing: border-box; padding: 0px 5px;">4</li><li style="box-sizing: border-box; padding: 0px 5px;">5</li><li style="box-sizing: border-box; padding: 0px 5px;">6</li><li style="box-sizing: border-box; padding: 0px 5px;">7</li></ul>

window操作符

window操作符非常类似于buffer操作符，区别在于buffer操作符产生的结果是一个List缓存，而window操作符产生的结果是一个Observable，订阅者可以对这个结果Observable重新进行订阅处理。

这里写图片描述

<code class="hljs avrasm has-numbering" style="display: block; padding: 0px; color: inherit; box-sizing: border-box; font-family: 'Source Code Pro', monospace;font-size:undefined; white-space: pre; border-radius: 0px; word-wrap: normal; background: transparent;">Observable<span class="hljs-preprocessor" style="color: rgb(68, 68, 68); box-sizing: border-box;">.interval</span>(<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span>, TimeUnit<span class="hljs-preprocessor" style="color: rgb(68, 68, 68); box-sizing: border-box;">.SECONDS</span>)<span class="hljs-preprocessor" style="color: rgb(68, 68, 68); box-sizing: border-box;">.take</span>(<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">12</span>)
                <span class="hljs-preprocessor" style="color: rgb(68, 68, 68); box-sizing: border-box;">.window</span>(<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">3</span>, TimeUnit<span class="hljs-preprocessor" style="color: rgb(68, 68, 68); box-sizing: border-box;">.SECONDS</span>)
                <span class="hljs-preprocessor" style="color: rgb(68, 68, 68); box-sizing: border-box;">.subscribe</span>(new Action1<Observable<Long>>() {
                    @Override
                    public void <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">call</span>(Observable<Long> observable) {
                        System<span class="hljs-preprocessor" style="color: rgb(68, 68, 68); box-sizing: border-box;">.out</span><span class="hljs-preprocessor" style="color: rgb(68, 68, 68); box-sizing: border-box;">.println</span>(<span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">"subdivide begin......"</span>)<span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">;</span>
                        observable<span class="hljs-preprocessor" style="color: rgb(68, 68, 68); box-sizing: border-box;">.subscribe</span>(new Action1<Long>() {
                            @Override
                            public void <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">call</span>(Long aLong) {
                                System<span class="hljs-preprocessor" style="color: rgb(68, 68, 68); box-sizing: border-box;">.out</span><span class="hljs-preprocessor" style="color: rgb(68, 68, 68); box-sizing: border-box;">.println</span>(<span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">"Next:"</span> + aLong)<span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">;</span>
                            }
                        })<span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">;</span>
                    }
                })<span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">;</span></code><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li><li style="box-sizing: border-box; padding: 0px 5px;">2</li><li style="box-sizing: border-box; padding: 0px 5px;">3</li><li style="box-sizing: border-box; padding: 0px 5px;">4</li><li style="box-sizing: border-box; padding: 0px 5px;">5</li><li style="box-sizing: border-box; padding: 0px 5px;">6</li><li style="box-sizing: border-box; padding: 0px 5px;">7</li><li style="box-sizing: border-box; padding: 0px 5px;">8</li><li style="box-sizing: border-box; padding: 0px 5px;">9</li><li style="box-sizing: border-box; padding: 0px 5px;">10</li><li style="box-sizing: border-box; padding: 0px 5px;">11</li><li style="box-sizing: border-box; padding: 0px 5px;">12</li><li style="box-sizing: border-box; padding: 0px 5px;">13</li><li style="box-sizing: border-box; padding: 0px 5px;">14</li></ul><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li><li style="box-sizing: border-box; padding: 0px 5px;">2</li><li style="box-sizing: border-box; padding: 0px 5px;">3</li><li style="box-sizing: border-box; padding: 0px 5px;">4</li><li style="box-sizing: border-box; padding: 0px 5px;">5</li><li style="box-sizing: border-box; padding: 0px 5px;">6</li><li style="box-sizing: border-box; padding: 0px 5px;">7</li><li style="box-sizing: border-box; padding: 0px 5px;">8</li><li style="box-sizing: border-box; padding: 0px 5px;">9</li><li style="box-sizing: border-box; padding: 0px 5px;">10</li><li style="box-sizing: border-box; padding: 0px 5px;">11</li><li style="box-sizing: border-box; padding: 0px 5px;">12</li><li style="box-sizing: border-box; padding: 0px 5px;">13</li><li style="box-sizing: border-box; padding: 0px 5px;">14</li></ul>

<code class="hljs sql has-numbering" style="display: block; padding: 0px; color: inherit; box-sizing: border-box; font-family: 'Source Code Pro', monospace;font-size:undefined; white-space: pre; border-radius: 0px; word-wrap: normal; background: transparent;">运行结果如下：
subdivide <span class="hljs-operator" style="box-sizing: border-box;"><span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">begin</span>……
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">Next</span>:<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">0</span>
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">Next</span>:<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span>
subdivide <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">begin</span>……
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">Next</span>:<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">2</span>
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">Next</span>:<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">3</span>
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">Next</span>:<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">4</span>
subdivide <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">begin</span>……
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">Next</span>:<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">5</span>
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">Next</span>:<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">6</span>
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">Next</span>:<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">7</span>
subdivide <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">begin</span>……
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">Next</span>:<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">8</span>
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">Next</span>:<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">9</span>
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">Next</span>:<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">10</span>
subdivide <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">begin</span>……
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">Next</span>:<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">11</span></span></code>