java后台get、post方法调用请求【常用方法】

POST请求：

  /***
     *
     * @param url
     * @param param
     * @return 发送返回响应
     * @throws IOException
     */
    public static String sendInfoPost(String url,String param) throws IOException {

        CloseableHttpClient httpclient = HttpClients.createDefault();

        HttpPost httppost = new HttpPost(url);
        httppost.addHeader("Content-Type", "application/x-www-form-urlencoded; charset=utf-8");

        String textMsg = param;
        StringEntity se = new StringEntity(textMsg, "utf-8");
        httppost.setEntity(se);
        String result = null;
        org.apache.http.HttpResponse response = httpclient.execute(httppost);
        if (response.getStatusLine().getStatusCode()== HttpStatus.SC_OK){
            result= EntityUtils.toString(response.getEntity(), "utf-8");
        }else{
            result= EntityUtils.toString(response.getEntity(), "utf-8");
        }

        return result;
    }

GET请求：

	     /** 
	      * 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) {  
	             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;  
	     }