利用DatagramSocket

我写的是一个用socket的，跟你要求的功能一样，你自己改改就可以了。

服务器端：
import java.awt.FlowLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.WindowAdapter;
import java.awt.event.WindowEvent;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.net.ServerSocket;
import java.net.Socket;

import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JTextArea;

class wangluo1 extends JFrame implements ActionListener {
JFrame frame = new JFrame();
JPanel panel1 = new JPanel();
JPanel panel2 = new JPanel();
JTextArea text1 = new JTextArea(30, 30);
//JTextArea text2 = new JTextArea(3, 25);
JButton sent = new JButton("转换");
InputStream in;
OutputStream out;
Socket client;
ServerSocket server;
String str;
Strin