06.Java网络编程（java GUI实现的聊天界面）

目前测试存在两个问题

1.最初是继承Frame来实现界面显示，后来发现，界面中部分控件存在时而显示时而不显示的问题，查找资料之后，将Frame修为JFrame，并且修改setVisible的时机，界面显示的问题解决，不显示的原因，有一种说法就是注释中提到的

2.界面显示问题解决之后，目前接收消息的线程无法正常接收，导致震动功能也无法实现，原因还有待进一步排查

package com.ren.socket;

import java.awt.BorderLayout;
import java.awt.Button;
import java.awt.Color;
import java.awt.Font;
import java.awt.Frame;
import java.awt.Panel;
import java.awt.TextArea;
import java.awt.TextField;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.KeyAdapter;
import java.awt.event.KeyEvent;
import java.awt.event.WindowAdapter;
import java.awt.event.WindowEvent;
import java.io.BufferedWriter;
import java.io.ByteArrayOutputStream;
import java.io.FileInputStream;
import java.io.FileWriter;
import java.io.IOException;
import java.net.DatagramPacket;
import java.net.DatagramSocket;
import java.net.InetAddress;
import java.net.SocketException;
import java.sql.Date;
import java.text.SimpleDateFormat;

import javax.swing.JFrame;

/**
 * 先调整窗口大小才会显示出组件，而不是立马显示出组件，在组件还未添加到面板前就将窗口
 * （JFrame）设为可见（setVisible（）），控件并不会引发重绘。解决方法很简单，
 * 只需要等所有组件都准备好以后才将JFrame的setVisible（）设置为true。
 * 非要在调用setVisible（）之后添加组件，那么你也可以这样做：getContentPane().invalidate();
 * 
 * 即便这样做了，也没有达到想要的效果
 */
public class GUIChat_UDP extends JFrame{
    
    private static final long serialVersionUID = 1L;
    private Button send;
    private Button log;
    private Button clear;
    private Button shake;
    private TextArea viewText;
    private TextArea sendText;
    private TextField tField;
    private DatagramSocket socket;
    private BufferedWriter writer;

    public GUIChat_UDP(){
        Init();
        southPanel();
        centerPanel();
        event();
        
        
        getContentPane().invalidate();
    }

    private void centerPanel() {
        Panel center = new Panel();
        //显示的文本区域
        viewText = new TextArea();
        //发送的文本区域
        sendText = new TextArea();
        //设置为边界布局管理器
        center.setLayout(new BorderLayout());
        //发送的文本区域放在南边
        center.add(sendText, BorderLayout.SOUTH);
        //显示区域放在中间
        center.add(viewText, BorderLayout.CENTER);
        //设置不可以编辑
        viewText.setEditable(false);
        //设置背景色
        viewText.setBackground(Color.WHITE);
        //设置字体大小
        sendText.setFont(new Font("xxx", Font.PLAIN, 15));
        viewText.setFont(new Font("xxx", Font.PLAIN, 15));
        //将这个panel设置在中间位置
        this.add(center,BorderLayout.CENTER);
        
    }

    private void southPanel() {
        Panel south = new Panel();
        //用于输入聊天对象的IP地址
        tField = new TextField(15);
        tField.setText("127.0.0.1");
        send = new Button("send");
        log = new Button("log");
        clear = new Button("clear");
        shake = new Button("shake");
        //添加如布局
        south.add(tField);
        south.add(send);
        south.add(log);
        south.add(clear);
        south.add(shake);
        
        this.add(south, BorderLayout.SOUTH);
        
    }

    private void Init() {
        this.setLocation(500, 50);
        this.setSize(400,600);
        this.setVisible(true);
        //开启接收消息线程
        new Receive().start();
        
        try {
            //初始化发送码头
            socket = new DatagramSocket();
            writer = new BufferedWriter(new FileWriter("log.txt",true));
        } catch (SocketException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
    

    private void event() {
        //关闭按钮事件
        this.addWindowListener(new WindowAdapter() {
            @Override
            public void windowClosing(WindowEvent e) {
                try {
                    socket.close();
                    writer.close();
                    System.exit(0);
                } catch (Exception e2) {
                }
            }
        });
        //发送按钮事件
        send.addActionListener(new ActionListener() {
            
            @Override
            public void actionPerformed(ActionEvent e) {
                try {
                    send();
                } catch (IOException e1) {
                    e1.printStackTrace();
                }
            }
        });
        //消息记录
        log.addActionListener(new ActionListener() {
            
            @Override
            public void actionPerformed(ActionEvent e) {
                try {
                    logFile();
                } catch (IOException e1) {
                    e1.printStackTrace();
                }
            }
        });
        //清空屏幕
        clear.addActionListener(new ActionListener() {
            
            @Override
            public void actionPerformed(ActionEvent e) {
                viewText.setText("");
            }
        });
        //震动
        shake.addActionListener(new ActionListener() {
            
            @Override
            public void actionPerformed(ActionEvent e) {
                try {
                    send(new byte[]{-1}, tField.getText());
                } catch (IOException e1) {
                    e1.printStackTrace();
                }
            }
        });
        //快捷键监听
        sendText.addKeyListener(new KeyAdapter() {
            @Override
            public void keyReleased(KeyEvent e) {
                //control+enter键发送消息
                if (e.getKeyCode() == KeyEvent.VK_ENTER && e.isControlDown()) {
                    try {
                        send();
                    } catch (Exception e2) {
                    }
                }
                
            }
        });
    }

    //通过不断改变界面在屏幕中的位置达到震动的效果
    protected void shake() {
        int x = this.getLocation().x;
        int y = this.getLocation().y;
        
        for (int i = 0; i < 10; i++) {
            try {
                this.setLocation(x + 10, y + 10);
                Thread.sleep(20);
                this.setLocation(x + 10, y - 10);
                Thread.sleep(20);
                this.setLocation(x - 10, y + 10);
                Thread.sleep(20);
                this.setLocation(x - 10, y - 10);
                Thread.sleep(20);
                this.setLocation(x, y);
            } catch (Exception e) {
            }
        }
    }

    protected void logFile() throws IOException {
        //刷新缓冲区
        writer.flush();
        //读取消息记录文件
        FileInputStream fis = new FileInputStream("log.txt");
        ByteArrayOutputStream baos = new ByteArrayOutputStream();
        
        int len;
        byte[] arr = new byte[8192];
        while((len = fis.read(arr))!= -1){
            baos.write(arr,0,len);
        }
        String log = baos.toString();
        viewText.setText(log);
        fis.close();
        baos.close();
    }

    protected void send() throws IOException {
        String message = sendText.getText();
        String ip = tField.getText();
        ip = ip.trim().length() == 0?"255.255.255.255":ip;
        send(message.getBytes(),ip);
        
        String time = getCurrentTime();
        String sendMessage = time+" 我对:"+(ip.equals("255.255.255.255")?"所有人":ip)+"说:\r\n "+message+"\r\n\r\n";
        viewText.append(sendMessage);
        //将发送的消息写入文件
        writer.write(sendMessage);
        sendText.setText("");
        
    }

    private void send(byte[] bytes, String ip) throws IOException {
        DatagramPacket packet = new DatagramPacket
                (bytes,bytes.length,InetAddress.getByName(ip),9999);
        socket.send(packet);
    }

    private String getCurrentTime() {
        Date date = new Date(System.currentTimeMillis());
        SimpleDateFormat format = new SimpleDateFormat("yyyy年MM月dd日HH:mm:ss");
        return format.format(date);
    }
    
    //接收消息的线程
    private class Receive extends Thread{
        @Override
        public void run() {
            super.run();
            try {
                DatagramSocket socket = new DatagramSocket(9999);
                DatagramPacket packet = new DatagramPacket(new byte[8192], 8192);
                while(true){
                    socket.receive(packet);
                    byte[]arr = packet.getData();
                    int len = packet.getLength();
                    
                    if (arr[0] == -1 && len == 1) {
                        shake();
                        continue;
                    }
                    
                    String message = new String(arr,0,len);
                    String time = getCurrentTime();
                    String ip = packet.getAddress().getHostAddress();
                    String receivedMessage = time+" "+ip+"对我说:\r\n"+message+"\r\n";
                    viewText.append(receivedMessage);
                    //写入收到的消息
                    writer.write(receivedMessage);
                }
            } catch (Exception e) {
            }
        }
    }

    public static void main(String[] args) {
        new GUIChat_UDP();
    }

}