如何使用Http客户端在java中传递查询参数

Question

我使用给定的代码在java中使用GET REST调用,但我收到错误代码:404即Not Found.但是当我在浏览器中使用相同的URL时,我得到了输出,它工作正常.我是JAVA的新手.可能是我错误地传递了查询参数,但我没有得到它.我在NETBEANS 7.1.2工作.请帮忙.

    import java.io.IOException;
    import java.io.OutputStreamWriter; 
    import java.net.HttpURLConnection; 
    import java.net.URL; 
       public class Test {
          private static String ENDPOINT ="http://wisekar.iitd.ernet.in/active/api_resources.php/method/mynode?";
          public static void main(String[] args) throws IOException 
          { 
              URL url = new URL(ENDPOINT + "key=" + "mykey"  );
              HttpURLConnection httpCon = (HttpURLConnection) url.openConnection(); 
              httpCon.setDoOutput(true);
              httpCon.setRequestMethod("GET");
             OutputStreamWriter out = new OutputStreamWriter( httpCon.getOutputStream());
             System.out.println(httpCon.getResponseCode());
             System.out.println(httpCon.getResponseMessage());
             out.close(); 
          }
   }

这里mykey是网站给我的关键.

我还想在输出窗口或控制台上打印响应消息.因为我想将它存储在将来进行一些提取.请帮忙.

Answer 1

这是你的代码..使用它.它正在回应401-Unauthorised我和浏览器URL上的相同响应,这可能是导致VPN的一些其他问题.如果你使用

private static String ENDPOINT ="http://google.com"; 

它会给你200-OK.

import java.io.IOException;
import java.net.HttpURLConnection;
import java.net.URL;
import java.net.URLEncoder;

       public class Test {
          private static String ENDPOINT ="http://wisekar.iitd.ernet.in/active/api_resources.php/method/mynode";
          public static void main(String[] args) throws IOException 
          { 
              String url = ENDPOINT;
              String charset = "UTF-8";
              String param1 = "mykey";

              String query = String.format("key=%s", 
                   URLEncoder.encode(param1, charset));
              java.net.URLConnection connection = new URL(url + "?" + query).openConnection();
              connection.setRequestProperty("Accept-Charset", charset);
              if ( connection instanceof HttpURLConnection)
              {
                 HttpURLConnection httpConnection = (HttpURLConnection) connection;
                 System.out.println(httpConnection.getResponseCode());
                 System.out.println(httpConnection.getResponseMessage());
              }
              else
              {
                 System.err.println ("error!");
              }
          }
   }