java代码发送JSON格式的httpPOST请求

<pre name="code" class="java">package com.test;import Java.io.BufferedReader;import java.io.DataOutputStream;import java.io.IOException;import java.io.InputStreamReader;import java.io.UnsupportedEncodingException;import java.net.HttpURLConnection;import java.net.MalformedURLException;import java.net.URL;import net.sf.json.JSONObject;public class AppAddTest {    public static final String ADD_URL = "www.2cto.com";    public static void appadd() {        try {            //创建连接            URL url = new URL(ADD_URL);            HttpURLConnection connection = (HttpURLConnection) url                    .openConnection();            connection.setDoOutput(true);            connection.setDoInput(true);            connection.setRequestMethod("POST");            connection.setUseCaches(false);            connection.setInstanceFollowRedirects(true);    //application/x-javascript text/xml->xml数据 application/x-javascript->json对象 application/x-www-form-urlencoded->表单数据 application/json;charset=utf-8 -> json数据            connection.setRequestProperty("Content-Type",                    "application/x-www-form-urlencoded");    connection.setRequestProperty("accept", "*/*");            connection.setRequestProperty("user-agent",                    "Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1;SV1)");            connection.connect();            //POST请求            DataOutputStream out = new DataOutputStream(                    connection.getOutputStream());            JSONObject obj = new JSONObject();            obj.element("app_name", "asdf");            obj.element("app_ip", "10.21.243.234");            obj.element("app_port", 8080);            obj.element("app_type", "001");            obj.element("app_area", "asd");            out.writeBytes(obj.toString());            out.flush();            out.close();            //读取响应            BufferedReader reader = new BufferedReader(new InputStreamReader(                    connection.getInputStream()));            String lines;            StringBuffer sb = new StringBuffer("");            while ((lines = reader.readLine()) != null) {                lines = new String(lines.getBytes(), "utf-8");                sb.append(lines);            }            System.out.println(sb);            reader.close();            // 断开连接            connection.disconnect();        } catch (MalformedURLException e) {            // TODO Auto-generated catch block            e.printStackTrace();        } catch (UnsupportedEncodingException e) {            // TODO Auto-generated catch block            e.printStackTrace();        } catch (IOException e) {            // TODO Auto-generated catch block            e.printStackTrace();        }    }    public static void main(String[] args) {        appadd();    }}