<?xml version="1.0" encoding="utf-8" ?><rss version="2.0"><channel><title><![CDATA[programmeruse的博客]]></title><description><![CDATA[]]></description><link>https://blog.youkuaiyun.com/programmeruse</link><language>zh-cn</language><generator>https://blog.youkuaiyun.com/</generator><copyright><![CDATA[Copyright &copy; programmeruse]]></copyright><item><title><![CDATA[javaScript操作数组的方法]]></title><link>https://blog.youkuaiyun.com/programmeruse/article/details/127805598</link><guid>https://blog.youkuaiyun.com/programmeruse/article/details/127805598</guid><author>programmeruse</author><pubDate>Fri, 11 Nov 2022 15:23:53 +0800</pubDate><description><![CDATA[操作数组的方法]]></description><category></category></item><item><title><![CDATA[未知主键的前提下，mysql查询主键字段]]></title><link>https://blog.youkuaiyun.com/programmeruse/article/details/127443507</link><guid>https://blog.youkuaiyun.com/programmeruse/article/details/127443507</guid><author>programmeruse</author><pubDate>Fri, 21 Oct 2022 11:53:50 +0800</pubDate><description><![CDATA[主键]]></description><category></category></item><item><title><![CDATA[依赖的作用域范围]]></title><link>https://blog.youkuaiyun.com/programmeruse/article/details/126889034</link><guid>https://blog.youkuaiyun.com/programmeruse/article/details/126889034</guid><author>programmeruse</author><pubDate>Fri, 16 Sep 2022 14:02:03 +0800</pubDate><description><![CDATA[依赖的作用域范围]]></description><category></category></item><item><title><![CDATA[isEmpty与isBlank]]></title><link>https://blog.youkuaiyun.com/programmeruse/article/details/126699860</link><guid>https://blog.youkuaiyun.com/programmeruse/article/details/126699860</guid><author>programmeruse</author><pubDate>Mon, 05 Sep 2022 10:32:51 +0800</pubDate><description><![CDATA[isEmpty 、 isBlank]]></description><category></category></item><item><title><![CDATA[解构表达式/模板字符串]]></title><link>https://blog.youkuaiyun.com/programmeruse/article/details/125113505</link><guid>https://blog.youkuaiyun.com/programmeruse/article/details/125113505</guid><author>programmeruse</author><pubDate>Fri, 03 Jun 2022 17:07:58 +0800</pubDate><description><![CDATA[解构赋值、字符串模板]]></description><category></category></item><item><title><![CDATA[java日期时间]]></title><link>https://blog.youkuaiyun.com/programmeruse/article/details/124254450</link><guid>https://blog.youkuaiyun.com/programmeruse/article/details/124254450</guid><author>programmeruse</author><pubDate>Tue, 26 Apr 2022 14:35:12 +0800</pubDate><description><![CDATA[世界标准时间UTC — — 2022-04-18T09:09:13.607
格林尼治标准时间GMT — — 18 Apr 2022 08:52:59 GMT
北京时间CST — — Mon Apr 18 16:54:35 CST 2022

日期时间、时间格式化、日历
与日期时间相关的类：
Date
JDK8以后新增的类有：
Clock、	Duration、	Instant
LocalDate、	LocalTime、	LocalDateTime及其相互转换
ZonedDateTime、	ZoneId
Ye.]]></description><category></category></item><item><title><![CDATA[spring注解有哪些]]></title><link>https://blog.youkuaiyun.com/programmeruse/article/details/122357172</link><guid>https://blog.youkuaiyun.com/programmeruse/article/details/122357172</guid><author>programmeruse</author><pubDate>Tue, 29 Mar 2022 09:36:42 +0800</pubDate><description><![CDATA[@SpringBootApplication
@Configuration
@ComponentScan，可自动发现和装配一些Bean。如果 没有配置的话，SpringBoot会扫描启动类所在包下以及子包下的使用了@Service，@Repository等注解的类
@EnableAutoConfiguration
@Component泛指组件，当组件不好归类的时候，可以使用这个注解进行标注。
@MapperScan
@ServletComponentScan
@Service一般用于修饰service层的.]]></description><category></category></item><item><title><![CDATA[vue+js在元素和函数中分别遍历对象及数组的异同]]></title><link>https://blog.youkuaiyun.com/programmeruse/article/details/123577383</link><guid>https://blog.youkuaiyun.com/programmeruse/article/details/123577383</guid><author>programmeruse</author><pubDate>Fri, 18 Mar 2022 16:39:15 +0800</pubDate><description><![CDATA[遍历对象，也就是说要遍历的数据是Object类型的{“key” : value}；
遍历数组，要遍历的数据是Array类型的[item1,item2]

在元素中遍历对象

&lt;div v-for="(value, key, index) in object"&gt;{{value}}{{key}}{{index}}&lt;/div&gt;
//如果此处只写了一个参数，就像下面这样，那么这个参数默认是object中的一个value
&lt;div v-for="(param) in object"&gt]]></description><category></category></item><item><title><![CDATA[canvsjTopo]]></title><link>https://blog.youkuaiyun.com/programmeruse/article/details/123045036</link><guid>https://blog.youkuaiyun.com/programmeruse/article/details/123045036</guid><author>programmeruse</author><pubDate>Tue, 22 Feb 2022 09:21:15 +0800</pubDate><description><![CDATA[&lt;canvs&gt;是HTML5新增的，通常使用JavaScript在其中绘制图像的HTML元素。
&lt;canvs&gt;只有两个可选属性width、height(width的默认值为300px，height默认值为150px)。使用css设置宽高时，如果和初始比例不一致，会出现扭曲。
&lt;canvs&gt;会创建一个固定大小的画布，公开一个或多个渲染上下文(画笔)，使用渲染上下文来绘制和处理要展示的内容，重点在2D渲染上下文。
var canvas = document.getElement]]></description><category></category></item><item><title><![CDATA[用vscode写.vue文件的辅助编辑]]></title><link>https://blog.youkuaiyun.com/programmeruse/article/details/122229386</link><guid>https://blog.youkuaiyun.com/programmeruse/article/details/122229386</guid><author>programmeruse</author><pubDate>Thu, 30 Dec 2021 09:40:49 +0800</pubDate><description><![CDATA[question 1：（windows）Ctrl+鼠标左键不能跳转到函数定义处
解决：安装vue-helper插件
自动闭合标签插件：Auto Close Tag
修改某个标签时，同步自动修改匹配的标签插件：Auto Rename Tag
匹配的括号对高亮显示插件：Bracket Pair Colorizer2


...]]></description><category></category></item><item><title><![CDATA[pip install 模块时出现socket.timeout:The read operation timed out异常]]></title><link>https://blog.youkuaiyun.com/programmeruse/article/details/121353478</link><guid>https://blog.youkuaiyun.com/programmeruse/article/details/121353478</guid><author>programmeruse</author><pubDate>Tue, 16 Nov 2021 12:57:29 +0800</pubDate><description><![CDATA[下载超时，下载时长超过默认时间，可以学长修改响应时间，如下：
windows环境下输入：pip --default-timeout=100 install 模块名；
Linux环境下输入：pip --default-timeout=100 install -U 模块名；

]]></description><category></category></item><item><title><![CDATA[java用于txt类文件读取]]></title><link>https://blog.youkuaiyun.com/programmeruse/article/details/121098260</link><guid>https://blog.youkuaiyun.com/programmeruse/article/details/121098260</guid><author>programmeruse</author><pubDate>Tue, 02 Nov 2021 13:37:21 +0800</pubDate><description><![CDATA[读取的形式可分为

按字节读取
按字符读取
按行读取

不管以什么样的方式读取，都要提供文件，这是肯定的。
不同的是，按字节读取使用InputStream.read()，按字符读取使用inputStreamReader.read()，而按行读取使用bufferedReader.readLine()
个人理解：

因为数据是以字节为单位存储的，如果要按字节读取，将file对象获取到inputStream就可以使用read()方法了；
如果要按字符读取，还要对字节流以某种方式进行编码，InputStreamRe]]></description><category></category></item><item><title><![CDATA[查找数组最值问题]]></title><link>https://blog.youkuaiyun.com/programmeruse/article/details/121033347</link><guid>https://blog.youkuaiyun.com/programmeruse/article/details/121033347</guid><author>programmeruse</author><pubDate>Fri, 29 Oct 2021 14:05:39 +0800</pubDate><description><![CDATA[先排序，后选定

Arrays.sort(array);
double min = array[0];
double max = array[array.length - 1];


使用Collections

Double[] array = new Double[]{3, 1, 2};
double min = (double)Collections.mix(Arrays.asList(array));
double max = (double)Collections.max(Arrays.asLi.]]></description><category></category></item><item><title><![CDATA[List与数组互相转换 / List求均值]]></title><link>https://blog.youkuaiyun.com/programmeruse/article/details/119948114</link><guid>https://blog.youkuaiyun.com/programmeruse/article/details/119948114</guid><author>programmeruse</author><pubDate>Fri, 15 Oct 2021 16:09:08 +0800</pubDate><description><![CDATA[List转数组
double[] arr2 = list.stream().mapToDouble(i-&gt;i).toArray();


]]></description><category></category></item><item><title><![CDATA[封装类型数组Double[]与基本类型数组double[]之间相互转换]]></title><link>https://blog.youkuaiyun.com/programmeruse/article/details/120270455</link><guid>https://blog.youkuaiyun.com/programmeruse/article/details/120270455</guid><author>programmeruse</author><pubDate>Mon, 13 Sep 2021 16:49:01 +0800</pubDate><description><![CDATA[double[] doubleArray = ArrayUtils.toPrimitive(DoubleArray);


]]></description><category></category></item><item><title><![CDATA[求数组均值]]></title><link>https://blog.youkuaiyun.com/programmeruse/article/details/120265380</link><guid>https://blog.youkuaiyun.com/programmeruse/article/details/120265380</guid><author>programmeruse</author><pubDate>Mon, 13 Sep 2021 13:29:40 +0800</pubDate><description><![CDATA[double mean = StatUtils.mean(doubleArray);

double average = Arrays.stream(array).average().orElse(Double.NaN);


]]></description><category></category></item><item><title><![CDATA[块元素和内联元素]]></title><link>https://blog.youkuaiyun.com/programmeruse/article/details/119574408</link><guid>https://blog.youkuaiyun.com/programmeruse/article/details/119574408</guid><author>programmeruse</author><pubDate>Tue, 10 Aug 2021 17:15:00 +0800</pubDate><description><![CDATA[块元素
内联元素




高度，行高，外边距(margin)，内边距(padding)都可控制
高，行高，外边距，内边距不可控制


宽度缺省是它的容器的100%
宽度就是内容的宽度，不可改变


可容纳块元素 和 内联元素
只能容纳 文本 或 其他内联元素


注意:内联元素设置width无效；
	 设置height无效，可以通过line-height来设置；
	 设置margin只有左右有效，上下无效；
	 设置padding只有左右有效，上下无效；

可通过display属性对内联元素 和 块...]]></description><category></category></item><item><title><![CDATA[Window键（开始键）没反应]]></title><link>https://blog.youkuaiyun.com/programmeruse/article/details/119447085</link><guid>https://blog.youkuaiyun.com/programmeruse/article/details/119447085</guid><author>programmeruse</author><pubDate>Fri, 06 Aug 2021 10:21:27 +0800</pubDate><description><![CDATA[可能是键被锁了，试试Fn+锁（F2）键，我的是F2，带了一个小锁标志

并且锁和大小写是不一样的



]]></description><category></category></item><item><title><![CDATA[echarts绘制回归曲线]]></title><link>https://blog.youkuaiyun.com/programmeruse/article/details/119100797</link><guid>https://blog.youkuaiyun.com/programmeruse/article/details/119100797</guid><author>programmeruse</author><pubDate>Thu, 29 Jul 2021 09:53:18 +0800</pubDate><description><![CDATA[echarts.registerTransform(ecStat.transform.regression);

var data = [
    [96.24, 11.35],
    [33.09, 85.11],
    [57.60, 36.61],
    [36.77, 27.26],
    [20.10, 6.72],
    [45.53, 36.37],
    [110.07, 80.13],
    [72.05, 20.88],
];

option = {
    dataset]]></description><category></category></item><item><title><![CDATA[保留4位小数]]></title><link>https://blog.youkuaiyun.com/programmeruse/article/details/119176797</link><guid>https://blog.youkuaiyun.com/programmeruse/article/details/119176797</guid><author>programmeruse</author><pubDate>Wed, 28 Jul 2021 12:47:21 +0800</pubDate><description><![CDATA[方法1

BigDecimal bd = new BigDeciaml(variable).setScale(4, BigDecimal.ROUND_HALF_UP);
double result1 = db.doubleValue();


方法2

DecimalFormat df = new DecimalFormat("#.0000");
String result2 = df.format(variable);


方法3

String result3 = String.format("%.4.]]></description><category></category></item></channel></rss>