java - 如何使用 HttpURLConnection 传递变量

Question

我有以下代码来获取 URL 的内容..

/*
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 * and open the template in the editor.
 */

package javaapplication3;

/**
 *
 * @author Ravi
 */
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.OutputStreamWriter;
import java.net.HttpURLConnection;
import java.net.MalformedURLException;
import java.net.ProtocolException;
import java.net.URL;

public class Main {

  /**
   * @param args
   */
  public static void main(String[] args) {
      HttpURLConnection connection = null;
      OutputStreamWriter wr = null;
      BufferedReader rd  = null;
      StringBuilder sb = null;
      String line = null;

      URL serverAddress = null;

      try {
          serverAddress = new URL("http://192.16.110.11:8084/RaviTest/index.jsp?id=3");
          //set up out communications stuff
          connection = null;

          //Set up the initial connection
          connection = (HttpURLConnection)serverAddress.openConnection();
          connection.setRequestMethod("GET");
          connection.setDoOutput(true);
          connection.setReadTimeout(10000);

          connection.connect();

          //get the output stream writer and write the output to the server
          //not needed in this example
          //wr = new OutputStreamWriter(connection.getOutputStream());
          //wr.write("");
          //wr.flush();

          //read the result from the server
          rd  = new BufferedReader(new InputStreamReader(connection.getInputStream()));
          sb = new StringBuilder();

          while ((line = rd.readLine()) != null)
          {
              sb.append(line + '\n');
          }

          System.out.println(sb.toString());

      } catch (MalformedURLException e) {
          e.printStackTrace();
      } catch (ProtocolException e) {
          e.printStackTrace();
      } catch (IOException e) {
          e.printStackTrace();
      }
      finally
      {
          //close the connection, set all objects to null
          connection.disconnect();
          rd = null;
          sb = null;
          wr = null;
          connection = null;
      }
  }
}

但是此代码仅复制指定 URL 的内容。

相反，如果我想连接到 jsp 页面，我可以获取该 JSP 页面动态发送的值吗...

例如，如果我有一个页面 http://192.16.110.51/WelcomeProject/index.jsp

我应该能够传递一个变量，然后index.jsp页面将向我传递回附加有hello world的变量，或者对变量进行一些操作并将结果发送回我。我怎样才能实现这一点？...如果不是 HttpURLConnection..是否还有其他方法可以完成此任务。

Answer 1

这是修改自的示例:http://www.java2s.com/Code/JavaAPI/java.net/URLConnectionsetDoOutputbooleandooutput.htm (我删除了响应部分，您可能实际上想要它)

import java.io.DataInputStream;
import java.io.DataOutputStream;
import java.net.URL;
import java.net.URLConnection;

public class MainClass {
  public static void main(String args[]) throws Exception {
    String query = "id=3";

    URLConnection uc = new URL("http://192.16.110.11:8084/RaviTest/index.jsp").openConnection();
    uc.setDoOutput(true);
    uc.setAllowUserInteraction(false);
    DataOutputStream dos = new DataOutputStream(uc.getOutputStream());

    // The POST line, the Accept line, and
    // the content-type headers are sent by the URLConnection.
    // We just need to send the data
    dos.writeBytes(query);
    dos.close();
  }

}