java发送http的get、post请求

    package wzh.Http;  
      
    import java.io.BufferedReader;  
    import java.io.IOException;  
    import java.io.InputStreamReader;  
    import java.io.PrintWriter;  
    import java.net.URL;  
    import java.net.URLConnection;  
    import java.util.List;  
    import java.util.Map;  
      
    public class HttpRequest {  
        /** 
         * 向指定URL发送GET方法的请求 
         *  
         * @param url 
         *            发送请求的URL 
         * @param param 
         *            请求参数，请求参数应该是 name1=value1&name2=value2 的形式。 
         * @return URL 所代表远程资源的响应结果 
         */  
        public static String sendGet(String url,String param) {  
            String result = "";  
            BufferedReader in = null;  
            try {  
                String urlNameString = url + "?" + param;  
                URL realUrl = new URL(urlNameString);  
                // 打开和URL之间的连接  
                URLConnection connection = realUrl.openConnection();  
                // 设置通用的请求属性  
                connection.setRequestProperty("accept","*/*");  
                connection.setRequestProperty("connection","Keep-Alive");  
                connection.setRequestProperty("user-agent","Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1;SV1)");  
                // 建立实际的连接  
                connection.connect();  
                // 获取所有响应头字段  
                Map<String,List<String>> map = connection.getHeaderFields();  
                // 遍历所有的响应头字段  
                for (String key : map.keySet()) {  
                    System.out.println(key + "--->" + map.get(key));  
                }  
                // 定义 BufferedReader输入流来读取URL的响应  
                in = new BufferedReader(new InputStreamReader(  
                        connection.getInputStream()));  
                String line;  
                while ((line = in.readLine()) != null) {  
                    result += line;  
                }  
            } catch (Exception e) {  
                System.out.println("发送GET请求出现异常！" + e);  
                e.printStackTrace();  
            }  
            // 使用finally块来关闭输入流  
            finally {  
                try {  
                    if (in != null) {  
                        in.close();  
                    }  
                } catch (Exception e2) {  
                    e2.printStackTrace();  
                }  
            }  
            return result;  
        }  
      
        /**  
         * 向指定 URL 发送POST方法的请求  
         *   
         * @param url  
         *            发送请求的 URL  
         * @param param  
         *            请求参数，请求参数应该是 name1=value1&name2=value2 的形式。  
         * @return 所代表远程资源的响应结果  
         */  
        public static String sendPost(String url,String param) {  
            PrintWriter out = null;  
            BufferedReader in = null;  
            String result = "";  
            try {  
                URL realUrl = new URL(url);  
                // 打开和URL之间的连接  
                URLConnection conn = realUrl.openConnection();  
                // 设置通用的请求属性  
                conn.setRequestProperty("accept","*/*");  
                conn.setRequestProperty("connection","Keep-Alive");  
                conn.setRequestProperty("user-agent","Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1;SV1)");  
                // 发送POST请求必须设置如下两行  
                conn.setDoOutput(true);  
                conn.setDoInput(true);  
                // 获取URLConnection对象对应的输出流  
                out = new PrintWriter(conn.getOutputStream());  
                // 发送请求参数  
                out.print(param);  
                // flush输出流的缓冲  
                out.flush();  
                // 定义BufferedReader输入流来读取URL的响应  
                in = new BufferedReader(  
                        new InputStreamReader(conn.getInputStream()));  
                String line;  
                while ((line = in.readLine()) != null) {  
                    result += line;  
                }  
            } catch (Exception e) {  
                System.out.println("发送 POST 请求出现异常！"+e);  
                e.printStackTrace();  
            }  
            //使用finally块来关闭输出流、输入流  
            finally{  
                try{  
                    if(out!=null){  
                        out.close();  
                    }  
                    if(in!=null){  
                        in.close();  
                    }  
                }  
                catch(IOException ex){  
                    ex.printStackTrace();  
                }  
            }  
            return result;  
        }      
    }  

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