java 通过发送json,post请求,返回json数据的方法

import java.io.BufferedReader;import java.io.DataOutputStream;import java.io.InputStream;import java.io.InputStreamReader;import java.io.OutputStream;import java.net.HttpURLConnection;import java.net.URL;import org.json.JSONArray;import org.json.JSONObject;public class GetJsonData {	public static String getJsonData(JSONObject jsonParam,String urls) {		StringBuffer sb=new StringBuffer();		try {			;			// 创建url资源			URL url = new URL(urls);			// 建立http连接			HttpURLConnection conn = (HttpURLConnection) url.openConnection();			// 设置允许输出			conn.setDoOutput(true);            // 设置允许输入            conn.setDoInput(true);            // 设置不用缓存            conn.setUseCaches(false);            // 设置传递方式            conn.setRequestMethod("POST");            // 设置维持长连接            conn.setRequestProperty("Connection", "Keep-Alive");            // 设置文件字符集:            conn.setRequestProperty("Charset", "UTF-8");            // 转换为字节数组            byte[] data = (jsonParam.toString()).getBytes();           // 设置文件长度            conn.setRequestProperty("Content-Length", String.valueOf(data.length));           // 设置文件类型:           conn.setRequestProperty("contentType", "application/json");            // 开始连接请求            conn.connect();		          OutputStream out = new DataOutputStream(conn.getOutputStream()) ;			// 写入请求的字符串			out.write((jsonParam.toString()).getBytes());			out.flush();			out.close();			System.out.println(conn.getResponseCode());						// 请求返回的状态			if (HttpURLConnection.HTTP_OK == conn.getResponseCode(){				System.out.println("连接成功");				// 请求返回的数据				InputStream in1 = conn.getInputStream();				try {				   String readLine=new String();				   BufferedReader responseReader=new BufferedReader(new InputStreamReader(in1,"UTF-8"));				   while((readLine=responseReader.readLine())!=null){				    sb.append(readLine).append("/n");				   }				   responseReader.close();				   System.out.println(sb.toString());									} catch (Exception e1) {					e1.printStackTrace();				}			} else {				System.out.println("error++");							}		} catch (Exception e) {		}				return sb.toString();	}	public static void main(String[] args) {		JSONObject jsonParam = new JSONObject();		jsonParam.put("id", "1401_1406");		jsonParam.put("device_size", "480x720");		String url="www.baidu.com";		String data=GetJsonData.getJsonData(jsonParam,url);        //返回的是一个[{}]格式的字符串时:                        JSONArray jsonArray = new JSONArray(data);                    //返回的是一个{}格式的字符串时:                    /*JSONObject obj= new JSONObject(data);*/     }}