httpclient3.java

《java网络编程精解》的源代码

import java.io.*;
import java.net.*;
import java.util.*;
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;

public class HttpClient3{  
  public static void main(String[] args){  
    JFrame frame = new PostTestFrame();
    frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    frame.setVisible(true);
  }
}

class PostTestFrame extends JFrame{  
   public static String doPost(String urlString, Map<String, String> nameValuePairs) 
      throws IOException{  
      URL url = new URL(urlString);
      URLConnection connection = url.openConnection();
      connection.setDoOutput(true);  //允许输出数据

      PrintWriter out = new PrintWriter(connection.getOutputStream());

      boolean first = true;
      for (Map.Entry<String, String> pair : nameValuePairs.entrySet()){  
         if (first) first = false; 
         else out.print('&'); 
         String name = pair.getKey();
         String value = pair.getValue();
         out.print(name);
         out.print('=');
         out.print(URLEncoder.encode(value, "GB2312"));  //请求正文采用GB2312编码
      }

      out.close();

      InputStream in=connection.getInputStream(); //读取响应正文
      ByteArrayOutputStream buffer=new ByteArrayOutputStream();
      byte[] buff=new byte[1024];  
      int len=-1;

      while((len=in.read(buff))!=-1){
        buffer.write(buff,0,len);
      }
     
      in.close();
      return new String(buffer.toByteArray()); //把字节数组转换为字符串
   }

   public PostTestFrame(){  
      setSize(DEFAULT_WIDTH, DEFAULT_HEIGHT);
      setTitle("卫琴书籍系列");

      JPanel northPanel = new JPanel();
      add(northPanel, BorderLayout.NORTH);

      final JComboBox combo = new JComboBox();
      for (int i = 0; i < books.length; i++)
      combo.addItem(books[i]);
      northPanel.add(combo);

      final JTextArea result = new JTextArea();
      add(new JScrollPane(result));

      JButton getButton = new JButton("查看");
      northPanel.add(getButton);
      getButton.addActionListener(new  ActionListener(){
            public void actionPerformed(ActionEvent event){  
               new Thread(new Runnable(){
                     public void run(){   
                        final String SERVER_URL = "http://www.javathinker.org/aboutBook.jsp";
                        result.setText("");
                        Map<String, String> post = new HashMap<String, String>();
                        post.put("title", books[combo.getSelectedIndex()]);
                        try{
                           result.setText(doPost(SERVER_URL, post));
                        }catch (IOException e){
                           result.setText("" + e);
                        }
                     }
                  }).start();
            }            
         });   
   }

   private static String[] books = {"Java面向对象编程", 
      "Tomcat与JavaWeb开发技术详解", 
      "精通Struts:基于MVC的JavaWeb设计与开发", 
      "精通Hibernate:Java对象持久化技术详解", 
      "Java2认证考试指南与试题解析"};

   public static final int DEFAULT_WIDTH = 400;
   public static final int DEFAULT_HEIGHT = 300;  
} 


/****************************************************
 * 作者：孙卫琴                                     *
 * 来源：<<Java网络编程精解>>                       *
 * 技术支持网址：www.javathinker.org                *
 ***************************************************/