public
class
HttpInvoker
...
{
public
static
final
String GET_URL
=
"
http://localhost:8080/welcome1
"
;
public
static
final
String POST_URL
=
"
http://localhost:8080/welcome1
"
;
public
static
void
readContentFromGet()
throws
IOException
...
{
//
拼凑get请求的URL字串,使用URLEncoder.encode对特殊和不可见字符进行编码
String getURL
=
GET_URL
+
"
?username=
"
+
URLEncoder.encode(
"
fat man
"
,
"
utf-8
"
);
URL getUrl
=
new
URL(getURL);
//
根据拼凑的URL,打开连接,URL.openConnection函数会根据URL的类型,
//
返回不同的URLConnection子类的对象,这里URL是一个http,因此实际返回的是HttpURLConnection
HttpURLConnection connection
=
(HttpURLConnection) getUrl
.openConnection();
//
进行连接,但是实际上get request要在下一句的connection.getInputStream()函数中才会真正发到
//
服务器
connection.connect();
//
取得输入流,并使用Reader读取
BufferedReader reader
=
new
BufferedReader(
new
InputStreamReader(
connection.getInputStream()));
System.out.println(
"
=============================
"
);
System.out.println(
"
Contents of get request
"
);
System.out.println(
"
=============================
"
);
String lines;
while
((lines
=
reader.readLine())
!=
null
)
...
{
System.out.println(lines);
}
reader.close();
//
断开连接
connection.disconnect();
System.out.println(
"
=============================
"
);
System.out.println(
"
Contents of get request ends
"
);
System.out.println(
"
=============================
"
);
}
public
static
void
readContentFromPost()
throws
IOException
...
{
//
Post请求的url,与get不同的是不需要带参数
URL postUrl
=
new
URL(POST_URL);
//
打开连接
HttpURLConnection connection
=
(HttpURLConnection) postUrl
.openConnection();
//
Output to the connection. Default is
//
false, set to true because post
//
method must write something to the
//
connection
//
设置是否向connection输出,因为这个是post请求,参数要放在
//
http正文内,因此需要设为true
connection.setDoOutput(
true
);
//
Read from the connection. Default is true.
connection.setDoInput(
true
);
//
Set the post method. Default is GET
connection.setRequestMethod(
"
POST
"
);
//
Post cannot use caches
//
Post 请求不能使用缓存
connection.setUseCaches(
false
);
//
This method takes effects to
//
every instances of this class.
//
URLConnection.setFollowRedirects是static函数,作用于所有的URLConnection对象。
//
connection.setFollowRedirects(true);
//
This methods only
//
takes effacts to this
//
instance.
//
URLConnection.setInstanceFollowRedirects是成员函数,仅作用于当前函数
connection.setInstanceFollowRedirects(
true
);
//
Set the content type to urlencoded,
//
because we will write
//
some URL-encoded content to the
//
connection. Settings above must be set before connect!
//
配置本次连接的Content-type,配置为application/x-www-form-urlencoded的
//
意思是正文是urlencoded编码过的form参数,下面我们可以看到我们对正文内容使用URLEncoder.encode
//
进行编码
connection.setRequestProperty(
"
Content-Type
"
,
"
application/x-www-form-urlencoded
"
);
//
连接,从postUrl.openConnection()至此的配置必须要在connect之前完成,
//
要注意的是connection.getOutputStream会隐含的进行connect。
connection.connect();
DataOutputStream out
=
new
DataOutputStream(connection
.getOutputStream());
//
The URL-encoded contend
//
正文,正文内容其实跟get的URL中'?'后的参数字符串一致
String content
=
"
firstname=
"
+
URLEncoder.encode(
"
一个大肥人
"
,
"
utf-8
"
);
//
DataOutputStream.writeBytes将字符串中的16位的unicode字符以8位的字符形式写道流里面
out.writeBytes(content);
out.flush();
out.close();
//
flush and close
BufferedReader reader
=
new
BufferedReader(
new
InputStreamReader(
connection.getInputStream()));
String line;
System.out.println(
"
=============================
"
);
System.out.println(
"
Contents of post request
"
);
System.out.println(
"
=============================
"
);
while
((line
=
reader.readLine())
!=
null
)
...
{
System.out.println(line);
}
System.out.println(
"
=============================
"
);
System.out.println(
"
Contents of post request ends
"
);
System.out.println(
"
=============================
"
);
reader.close();
connection.disconnect();
}
/** */
/**
*
@param
args
*/
public
static
void
main(String[] args)
...
{
//
TODO Auto-generated method stub
try
...
{
readContentFromGet();
readContentFromPost();
}
catch
(IOException e)
...
{
//
TODO Auto-generated catch block
e.printStackTrace();
}
}
}
HttpURLConnection
最新推荐文章于 2022-05-16 16:25:20 发布