java发送http的get、post请求

              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;
 23try {
 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 37for (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;
 44while ((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 52finally {
 53try {
 54if (in != null) {
 55                    in.close();
 56                }
 57             } catch (Exception e2) {
 58                e2.printStackTrace();
 59            }
 60        }
 61return 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*/ 71publicstatic String sendPost(String url, String param) {
 72         PrintWriter out = null;
 73         BufferedReader in = null;
 74         String result = "";
 75try {
 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(
 94new InputStreamReader(conn.getInputStream()));
 95            String line;
 96while ((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104finally {
105try {
106if (out != null) {
107                    out.close();
108                }
109if (in != null) {
110                    in.close();
111                }
112             } catch (IOException ex) {
113                ex.printStackTrace();
114            }
115        }
116return 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);
    }