HttpURLConnection

1.获取HttpURLConnection实例，一般new出一个URL对象并且传入目标网络地址，再调用openConnection();

URL url = new URL("http://localhost:8080/TestHttpURLConnectionPro/index.jsp"); 
HttpURLConnection connection = (HttpURLConnection)url.openConnection(); 

2.设置Get/Post

connection.setRequestMethod("POST");  

3.设置链接超时、读取超时毫秒数，消息头等

connection.setConnectTimeout(8000);
connection.setReadTimeout(8000);

4.getInputStream()获取服务器返回的输入流

InputStream in = connection.getInputStream();

5.关闭HTTP链接

connection.disConnect();