客户端与服务器的对话程序，有UI界面

package com.info.window; import java.awt.Container; import java.awt.FlowLayout; import java.awt.event.ActionEvent; import java.awt.event.ActionListener; import java.io.BufferedReader; import java.io.InputStreamReader; import java.io.OutputStreamWriter; import java.io.PrintWriter; import java.net.InetAddress; import java.net.InetSocketAddress; import java.net.Socket; import java.net.SocketAddress; import javax.swing.JButton; import javax.swing.JFrame; import javax.swing.JLabel; import javax.swing.JOptionPane; import javax.swing.JPanel; import javax.swing.JTextArea; import javax.swing.JTextField; public class Client extends JFrame { private JPanel p1, p2, p3, p5, p6, p7; private JLabel lb1, lb2, lb3, lb4, lb5; private Container container; private JTextField t1, t2, t3; private static JTextArea ta; private JButton bt1, bt2; public Client(){ this.setTitle("客户机"); container = this.getContentPane(); container.setLayout(new FlowLayout(FlowLayout.LEFT)); lb1 = new JLabel("通信面板"); lb2 = new JLabel("服务器主机名："); lb3 = new JLabel("服务器端口："); lb4 = new JLabel("待发送消息："); lb5 = new JLabel("服务器Echo消息面板"); bt1 = new JButton("连接服务器"); bt2 = new JButton(" 发 言 "); bt1.addActionListener(new bt1ActionListener()); bt2.addActionListener(new bt2ActionListener()); t1 = new JTextField(10); t2 = new JTextField(5); t3 = new JTextField(25); ta = new JTextArea(15, 40); p1 = new JPanel(); p2 = new JPanel(); p3 = new JPanel(); p5 = new JPanel(); p6 = new JPanel(); p7 = new JPanel(); p1.add(lb1); container.add(p1); p2.add(lb2); p2.add(t1); p2.add(lb3); p2.add(t2); p2.add(bt1); container.add(p2); p3.add(lb4); p3.add(t3); p3.add(bt2); container.add(p3); p5.add(lb5); container.add(p5); p6.add(ta); p7.add(p6); container.add(p7); this.setSize(500, 500); this.setVisible(true); this.setResizable(false); } private Socket clientSocket = null; private BufferedReader in; private PrintWriter out; public class bt1ActionListener implements ActionListener { public void actionPerformed(ActionEvent arg0) { try { bt1.setEnabled(false); String remoteName = t1.getText(); int remotePort = Integer.parseInt(t2.getText()); SocketAddress remoteAddr = new InetSocketAddress( InetAddress.getByName(remoteName),remotePort); clientSocket = new Socket(); clientSocket.connect(remoteAddr); ta.append("连接服务器成功，会话开始…\n"); out = new PrintWriter(new OutputStreamWriter( clientSocket.getOutputStream(),"UTF-8"),true); in = new BufferedReader(new InputStreamReader( clientSocket.getInputStream(),"UTF-8")); } catch (Exception e) { JOptionPane.showConfirmDialog(null, e.getMessage(), "连接错误",JOptionPane.ERROR_MESSAGE); return; } } } public class bt2ActionListener implements ActionListener { public void actionPerformed(ActionEvent arg0) { if(clientSocket == null){ JOptionPane.showMessageDialog(null, "请先检查服务器连接情况。\n确保客户及连接服务器！", "错误提示", JOptionPane.ERROR_MESSAGE); return; } String outStr = t3.getText(); if(outStr.length() == 0){ JOptionPane.showMessageDialog(null, "请输入发送消息！", "提示", JOptionPane.ERROR_MESSAGE); return; } out.println(outStr); t3.setText(""); try { String inStr; inStr = in.readLine(); ta.append("Echo:" + inStr + "\n"); } catch (Exception e) { JOptionPane.showMessageDialog(null, "客户机接收消息错误！", "错误提示", JOptionPane.ERROR_MESSAGE); return; } } } private void formWindowClosing(java.awt.event.WindowEvent evt){ try { if(in != null)in.close(); if(out != null)out.close(); if(clientSocket != null)clientSocket.close(); } catch (Exception e) {} } public static void main(String[] args) { new Client(); } }