基于DES加密的java Socket 程序（服务器端）

server端程序：

import java.awt.BorderLayout;
import java.awt.Container;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.io.BufferedInputStream;
import java.io.BufferedReader;
import java.io.DataInputStream;
import java.io.DataOutputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import java.io.OutputStream;
import java.io.PrintWriter;
import java.net.*;
import java.util.concurrent.*;

import javax.swing.Box;
import javax.swing.JButton;
import javax.swing.JFileChooser;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
import javax.swing.JTextArea;
import javax.swing.JTextField;

public class server extends JFrame{
 private ObjectInputStream m_input;
 private ObjectOutputStream m_output;
 private JTextField m_enter;
 private JTextArea m_display;

 private int m_clientNumber = 0;
 private Box box1;
    public server()  throws IOException{
    
     super("聊天程序服务器端");
  Container c = getContentPane();
 
 
  m_enter = new JTextField();
  m_enter.setEnabled(false);
  m_enter.addActionListener(new ActionListener() {
   public void actionPerformed(ActionEvent event) {
    try {
     String s = event.getActionCommand();
    
     DesEncrypt des = new DesEncrypt(); // 实例化一个对像

     des.getKey("aadd"); // 生成密匙
     String strEnc = des.getEncString(s);//加密字符串,返回String的密文
     m_output.writeObject(strEnc);
    
     m_output.flush();
    
     mb_displayAppend("服务器端:"+s);
     m_enter.setText("");
    } catch (Exception e) {
     System.err.println("发生异常：" + e);
     e.printStackTrace();

    }
   }
  });
 
 
  c.add(m_enter, BorderLayout.NORTH);
  m_display = new JTextArea();
  c.add(new JScrollPane(m_display), BorderLayout.CENTER);

     }

  
    
    public void mb_displayAppend(String s) {
  m_display.append(s + "/n");
  m_display.setCaretPosition(m_display.getText().length());
  m_enter.requestFocusInWindow();
 }

 public boolean mb_isEndSession(String m) {
  if (m.equalsIgnoreCase("q"))
   return (true);
  if (m.equalsIgnoreCase("quit"))
   return (true);
  if (m.equalsIgnoreCase("exit"))
   return (true);
  if (m.equalsIgnoreCase("end"))
   return (true);
  if (m.equalsIgnoreCase("结束"))
   return (true);
  return (false);
 }

 public void mb_run() {
  try {
   ServerSocket server = new ServerSocket(5000);
   String m;
   String strDes,senq;
   while (true) {
    m_clientNumber++;
    mb_displayAppend("等待连接[" + m_clientNumber + "]");
    Socket s = server.accept();
    mb_displayAppend("接收客户端连接[" + m_clientNumber + "]");
    m_output = new ObjectOutputStream(s.getOutputStream());
    m_input = new ObjectInputStream(s.getInputStream());
    m_output.writeObject("连接成功");
    m_output.flush();
    m_enter.enable(true);
    do {
     m = (String) m_input.readObject();
     DesEncrypt des = new DesEncrypt(); // 实例化一个对像

     des.getKey("aadd"); // 生成密匙
    strDes = des.getDesString(m); // 把String 类型的密文解密
    senq=des.getEncString("q");
     mb_displayAppend("客户端为解密之前的信息为："+m);
     mb_displayAppend("客户端：" + strDes);

    } while (!mb_isEndSession(strDes));
    m_output.writeObject(senq);
    m_output.flush();
    m_enter.setEnabled(false);
    m_output.close();
    m_input.close();
   mb_displayAppend("连接[" + m_clientNumber + "]");

   }

  } catch (Exception e) {
   System.err.println("发生异常:" + e);
   e.printStackTrace();
   mb_displayAppend("连接[" + m_clientNumber + "]异常");

  }
 }
    public static void main(String[] args) throws IOException {
     server app=new server();
  app.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
  app.setSize(500,400);
  app.setVisible(true);
 
  app.mb_run();
 
    }

}