1 package com.study.test;  2   3 import java.io.BufferedReader;  4 import java.io.IOException;  5 import java.io.InputStreamReader;  6 import java.io.PrintWriter;  7 import java.net.URL;  8 import java.net.URLConnection;  9 import java.util.List; 10 import java.util.Map; 11  12 public class HttpRequest { 13     /** 14      * 向指定URL发送GET方法的请求 15      * 16      * @param url   发送请求的URL 17      * @param param 请求参数，请求参数应该是 name1=value1&name2=value2 的形式。 18      * @return URL 所代表远程资源的响应结果 19      */ 20     public static String sendGet(String url, String param) { 21         String result = ""; 22         BufferedReader in = null; 23         try { 24             String urlNameString = url + "?" + param; 25             URL realUrl = new URL(urlNameString); 26             // 打开和URL之间的连接 27             URLConnection connection = realUrl.openConnection(); 28             // 设置通用的请求属性 29             connection.setRequestProperty("accept", "*/*"); 30             connection.setRequestProperty("connection", "Keep-Alive"); 31             connection.setRequestProperty("user-agent", "Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1;SV1)"); 32             // 建立实际的连接 33             connection.connect(); 34             // 获取所有响应头字段 35             Map<String, List<String>> map = connection.getHeaderFields(); 36             // 遍历所有的响应头字段 37             for (String key : map.keySet()) { 38                 System.out.println(key + "--->" + map.get(key)); 39             } 40             // 定义 BufferedReader输入流来读取URL的响应 41             in = new BufferedReader(new InputStreamReader( 42                     connection.getInputStream())); 43             String line; 44             while ((line = in.readLine()) != null) { 45                 result += line; 46             } 47         } catch (Exception e) { 48             System.out.println("发送GET请求出现异常！" + e); 49             e.printStackTrace(); 50         } 51         // 使用finally块来关闭输入流 52         finally { 53             try { 54                 if (in != null) { 55                     in.close(); 56                 } 57             } catch (Exception e2) { 58                 e2.printStackTrace(); 59             } 60         } 61         return result; 62     } 63  64     /** 65      * 向指定 URL 发送POST方法的请求 66      * 67      * @param url   发送请求的 URL 68      * @param param 请求参数，请求参数应该是 name1=value1&name2=value2 的形式。 69      * @return 所代表远程资源的响应结果 70      */ 71     public static String sendPost(String url, String param) { 72         PrintWriter out = null; 73         BufferedReader in = null; 74         String result = ""; 75         try { 76             URL realUrl = new URL(url); 77             // 打开和URL之间的连接 78             URLConnection conn = realUrl.openConnection(); 79             // 设置通用的请求属性 80             conn.setRequestProperty("accept", "*/*"); 81             conn.setRequestProperty("connection", "Keep-Alive"); 82             conn.setRequestProperty("user-agent", "Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1;SV1)"); 83             // 发送POST请求必须设置如下两行 84             conn.setDoOutput(true); 85             conn.setDoInput(true); 86             // 获取URLConnection对象对应的输出流 87             out = new PrintWriter(conn.getOutputStream()); 88             // 发送请求参数 89             out.print(param); 90             // flush输出流的缓冲 91             out.flush(); 92             // 定义BufferedReader输入流来读取URL的响应 93             in = new BufferedReader( 94                     new InputStreamReader(conn.getInputStream())); 95             String line; 96             while ((line = in.readLine()) != null) { 97                 result += line; 98             } 99         } catch (Exception e) {100             System.out.println("发送 POST 请求出现异常！" + e);101             e.printStackTrace();102         }103         //使用finally块来关闭输出流、输入流104         finally {105             try {106                 if (out != null) {107                     out.close();108                 }109                 if (in != null) {110                     in.close();111                 }112             } catch (IOException ex) {113                 ex.printStackTrace();114             }115         }116         return result;117     }118 }

    public static void main(String[] args) {        //发送 GET 请求        String s = HttpRequest.sendGet("http://localhost:8080/rings/receive", "key=123&v=456");        System.out.println(s);        //发送 POST 请求        String sr = HttpRequest.sendPost("http://localhost:8080/rings/receive", "key=123&v=456");        System.out.println(sr);    }