Java Json Post 请求

package com.xin.web.action;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 ImportData {    public static final String BASE_URL = "https://iot.wuliancloud.com/sso/";    public static final String GET_TOKEN_URL = BASE_URL + "partner/tokens";    public static void appadd() {        try {            // 创建连接            URL url = new URL(GET_TOKEN_URL);            HttpURLConnection connection = (HttpURLConnection) url                    .openConnection();            connection.setDoOutput(true);            connection.setDoInput(true);            connection.setRequestMethod("POST");            connection.setUseCaches(false);            connection.setInstanceFollowRedirects(true);//          connection.setRequestProperty("Content-Type",//                  "application/x-www-form-urlencoded");            connection.setRequestProperty("Content-Type", "application/json");            connection.connect();            // POST请求            DataOutputStream out = new DataOutputStream(                    connection.getOutputStream());            JSONObject obj = new JSONObject();            obj.element("partnerId", "*************");            obj.element("partnerKey", "****************");            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();    }}