URLConnection

HttpURLConnection继承自URLConnection,差别在与HttpURLConnection仅仅针对Http连接。我们在开发中一般是使用HttpURLConnection.

关键点在于是getInputStream()完成一次真正的请求

import java.io.InputStream;
import java.io.OutputStream;
import java.net.URL;
import java.net.URLConnection;



public class URLConnectionTest {
    public static void main(String[] args){
        try{
            URL url=new URL("");
            URLConnection urlConnection=url.openConnection();

            //这是几个简单属性
            urlConnection.setDoInput(true);
            urlConnection.setDoOutput(true);
            urlConnection.setUseCaches(false);
            urlConnection.setConnectTimeout(2000);

            // 设定传送的内容类型是可序列化的java对象
         // (如果不设此项,在传送序列化对象时,当WEB服务默认的不是这种类型时可能抛java.io.EOFException)
            urlConnection.setRequestProperty("Content-type","application/x-www-form-urlencoded");

            //connect()可要可不要，连接的关键在于调用getInputStream()方法
            urlConnection.connect();

            //如果在url中没有加入参数,可以用getOutPutStream()方法将参数写入缓冲区中
            //真正的完成一次请求是要调用getInputStream()方法,即在调用getInputStream()前
            //都没有开始请求
            OutputStream outputStream=urlConnection.getOutputStream();
            String param="name=xiebiao";
            outputStream.write(param.getBytes());

            //读取servlet返回的数据
            InputStream inputStream=urlConnection.getInputStream();
            byte[] buffer=new byte[inputStream.available()];
            inputStream.read(buffer);
            System.out.println(new String(buffer));
        }catch(Exception ex){
            ex.printStackTrace();
        }
    }

}