java模拟post请求发送json

java模拟post请求发送json，用两种方式实现，第一种是HttpURLConnection发送post请求，第二种是使用httpclient模拟post请求，

方法一：

 1 package main.utils;
 2
 3 import java.io.*;
 4 import java.net.HttpURLConnection;
 5 import java.net.URL;
 6
 7 public class HttpUtilTest {
 8     Log log = new Log(this.getClass());//初始化日志类
 9     /**
10      * @作用 使用urlconnection
11      * @param url
12      * @param Params
13      * @return
14      * @throws IOException
15      */
16     public String sendPost(String url,String Params)throws IOException{
17         OutputStreamWriter out = null;
18         BufferedReader reader = null;
19         String response="";
20         try {
21             URL httpUrl = null; //HTTP URL类 用这个类来创建连接
22             //创建URL
23             httpUrl = new URL(url);
24             //建立连接
25             HttpURLConnection conn = (HttpURLConnection) httpUrl.openConnection();
26             conn.setRequestMethod("POST");
27             conn.setRequestProperty("Content-Type", "application/json");
28             conn.setRequestProperty("connection", "keep-alive");
29             conn.setUseCaches(false);//设置不要缓存
30             conn.setInstanceFollowRedirects(true);
31             conn.setDoOutput(true);
32             conn.setDoInput(true);
33             conn.connect();
34             //POST请求
35             out = new OutputStreamWriter(
36                     conn.getOutputStream());
37             out.write(Params);
38             out.flush();
39             //读取响应
40             reader = new BufferedReader(new InputStreamReader(
41                     conn.getInputStream()));
42             String lines;
43             while ((lines = reader.readLine()) != null) {
44                 lines = new String(lines.getBytes(), "utf-8");
45                 response+=lines;
46             }
47             reader.close();
48             // 断开连接
49             conn.disconnect();
50
51             log.info(response.toString());
52         } catch (Exception e) {
53         System.out.println("发送 POST 请求出现异常！"+e);
54         e.printStackTrace();
55         }
56         //使用finally块来关闭输出流、输入流
57         finally{
58         try{
59             if(out!=null){
60                 out.close();
61             }
62             if(reader!=null){
63                 reader.close();
64             }
65         }
66         catch(IOException ex){
67             ex.printStackTrace();
68         }
69     }
70
71         return response;
72     }
73 }

　方法二：使用httpclient实现

 1 //post请求方法
 2     public  String sendPost(String url, String data) {
 3         String response = null;
 4         log.info("url: " + url);
 5         log.info("request: " + data);
 6         try {
 7             CloseableHttpClient httpclient = null;
 8             CloseableHttpResponse httpresponse = null;
 9             try {
10                 httpclient = HttpClients.createDefault();
11                 HttpPost httppost = new HttpPost(url);
12                 StringEntity stringentity = new StringEntity(data,
13                         ContentType.create("text/json", "UTF-8"));
14                 httppost.setEntity(stringentity);
15                 httpresponse = httpclient.execute(httppost);
16                 response = EntityUtils
17                         .toString(httpresponse.getEntity());
18                 log.info("response: " + response);
19             } finally {
20                 if (httpclient != null) {
21                     httpclient.close();
22                 }
23                 if (httpresponse != null) {
24                     httpresponse.close();
25                 }
26             }
27         } catch (Exception e) {
28             e.printStackTrace();
29         }
30         return response;
31     }