java发送post 的json请求

package com.elink.estos.mq.mqmanager;import java.io.IOException;import java.io.InputStream;import java.io.OutputStreamWriter;import java.net.HttpURLConnection;import java.net.URL;import java.io.BufferedReader;import java.io.InputStreamReader;public class JavaPostJson2 { final static String url = "http://localhost:1111/sendData"; final static String params = "{\"token\":\"12345\"," + "\"appId\":\"20180628173051169c85d965d164ed9ab1281d22ff350ec19\"" + "\"appName\":\"test33\"" + "\"classTopic\":\"112\"" + "\"eventTag\":\"22\"" + "}"; public static void main(String[] args) { String res = post(url, params); System.out.println(res); } /** * 发送HttpPost请求 * * @param strURL * 服务地址 * @param params * json字符串,例如: "{ \"id\":\"12345\" }" ;其中属性名必须带双引号<br/> * @return 成功:返回json字符串<br/> */ public static String post(String strURL, String params) { System.out.println(strURL); System.out.println(params); BufferedReader reader = null; try { URL url = new URL(strURL);// 创建连接 HttpURLConnection connection = (HttpURLConnection) url.openConnection(); connection.setDoOutput(true); connection.setDoInput(true); connection.setUseCaches(false); connection.setInstanceFollowRedirects(true); connection.setRequestMethod("POST"); // 设置请求方式 // connection.setRequestProperty("Accept", "application/json"); // 设置接收数据的格式 connection.setRequestProperty("Content-Type", "application/json"); // 设置发送数据的格式 connection.connect(); //一定要用BufferedReader 来接收响应， 使用字节来接收响应的方法是接收不到内容的 OutputStreamWriter out = new OutputStreamWriter(connection.getOutputStream(), "UTF-8"); // utf-8编码 out.append(params); out.flush(); out.close(); // 读取响应 reader = new BufferedReader(new InputStreamReader(connection.getInputStream(), "UTF-8")); String line; String res = ""; while ((line = reader.readLine()) != null) { res += line; } reader.close(); //如果一定要使用如下方式接收响应数据， 则响应必须为: response.getWriter().print(StringUtils.join("{\"errCode\":\"1\",\"errMsg\":\"", message, "\"}")); 来返回// int length = (int) connection.getContentLength();// 获取长度// if (length != -1) {// byte[] data = new byte[length];// byte[] temp = new byte[512];// int readLen = 0;// int destPos = 0;// while ((readLen = is.read(temp)) > 0) {// System.arraycopy(temp, 0, data, destPos, readLen);// destPos += readLen;// }// String result = new String(data, "UTF-8"); // utf-8编码// System.out.println(result);// return result;// } return res; } catch (IOException e) { // TODO Auto-generated catch block e.printStackTrace(); } return "error"; // 自定义错误信息 }}