chatapplet.java

该程序用java实现了白板功能。。。。。。。。。。。。。。。。

import java.net.*;
import java.io.*;
import java.awt.*;
import java.util.*;
import java.applet.*;

/*
  A basic extension of the java.applet.Applet class
 */

//class 7:ChatApplet，电子白板客户端Applet核心类 
public class ChatApplet extends Applet
   implements Runnable {

 volatile boolean logged=false;
 volatile boolean belongRoom=false;
 volatile boolean paused=false;
 volatile boolean roomDataValid=false;
 URL url=null;
 int port=0;
 Socket s=null;
 Color currentColor=null;
 int x0=0,y0=0,x1=0,y1=0;
 String userName=null;
 String roomName=null;
 int roomID=0;
 Rooms rooms=null;
 Thread thread=null;
 DataInputStream io_in=null;
 DataOutputStream io_out=null;
 DataOutputStream piped_out=null;
 SendDrawData sender=null;
 int logo_x=0,logo_y=0,logo_width=0,logo_height=0;

 public void start() {
  if (thread==null) {
   thread=new Thread(this);
   thread.start();
  }
 }
 // method 'start' ended

 public void stop() {
  if (thread!=null) {
   quitButton_Clicked(new Event(this,0,null));
   message_TextArea.setText("");
   thread.stop();
   thread=null;
  }
 }
 //method 'stop' ended

 public void destroy() {
  try{
   commandCenter("ask_quit",new DataBag
    ("none","none",0,0,0,0,0));
   if (sender!=null) {
    sender.quit();
    sender=null;
   }
   socketClose();
  }catch(Exception e){
   System.out.println(e);
  }
 }
 //method 'destroy' close

 public void socketClose() {
  try{
   piped_out.flush();
   piped_out.close();
   piped_out=null;
  }catch(IOException e){
   System.out.println(e);
  }
  try{
   io_in.close();
   io_in=null;
  }catch(Exception e){}
  try{
   io_out.flush();
   io_out.close();
   io_out=null;
  }catch(Exception e){}
  try{
   s.close();
   s=null;
  }catch(Exception e){}
 }
 //method 'socketClose' ended

 public void commandCenter(String
   command,DataBag data) throws PleaseCloseSocketException {
  if (command.equals("ask_refresh")) client_ask_refresh();
   else if (command.equals("refresh")) client_answer_refresh();
   else if (command.equals("ask_log")) client_ask_log();
   else if (command.equals("ask_join")) client_ask_join();
   else if (command.equals("ask_pause")) client_ask_pause();
   else if (command.equals("ask_continue")) client_ask_continue();
   else if (command.equals("ask_new")) client_ask_newRoom();
   else if (command.equals("ask_quit")) client_ask_quit();
   else if (command.equals("ask_text")) client_ask_text(data);
   else if (command.equals("text")) client_answer_text();
   else if (command.equals("draw")) client_answer_draw();

 }// method commandCenter ended

 private void client_answer_text() throws PleaseCloseSocketException{

  String message=null;
  String name=null;
  DataBag data=null;

  try{
   name=io_in.readUTF();
   message=io_in.readUTF();
   data=new DataBag(name,message,0,0,0,0,0);
   printChat_Area(data);

  }catch(IOException e){
    message_TextArea.appendText("抱歉，无法正确接受句子");
    throw new PleaseCloseSocketException();

  }
 }//method 'client_answer_text' ended

 private void client_answer_draw() throws PleaseCloseSocketException {

  DataBag data=null;
  int color=0,x0=0,y0=0,x1=0,y1=0;

  try{
   color=io_in.readInt();
   x0=io_in.readShort();
   y0=io_in.readShort();
   x1=io_in.readShort();
   y1=io_in.readShort();

   data=new DataBag("none","none",color,x0,y0,x1,y1);
   drawBoard_Canvas(data);

  }catch(IOException e){
    message_TextArea.appendText("抱歉，无法正确接受图形");
    throw new PleaseCloseSocketException();

  }
 }//mwthod 'client_answer_draw' ended

 private void client_ask_text(DataBag data)
    throws PleaseCloseSocketException {

  String message=null;

  try{
   synchronized(sender){
    io_out.writeUTF("text");
    io_out.writeUTF(data.message);
   }
  }catch(IOException e){
   throw new PleaseCloseSocketException();
  }

 }// method 'client_ask_text' ended

 private void client_ask_refresh() throws PleaseCloseSocketException {

  try{
    if (sender!=null) {
    synchronized(sender){
     io_out.writeUTF("refresh");
    }
   }else{
    io_out.writeUTF("refresh");
   }
  }catch(IOException e){
    roomDataValid=false;
    throw new PleaseCloseSocketException();
  }

 }// method 'client_ask_refresh' ended

 private void client_answer_refresh() 
    throws PleaseCloseSocketException {

  String message=null;
  RoomData roomData=null;
  int roomID=0;

  rooms=new Rooms(10,5);
  try{
   while(!((message=io_in.readUTF()).equals("ok"))) {
    roomData=new RoomData(message);
    rooms.addElement(roomData);
    while(!(message=io_in.readUTF()).equals("complete")) {
     roomData.addUser(message);
    }
   }
  message=io_in.readUTF();
  rooms.setDefault(message);

  roomDataValid=true;
  refreshRoomList();

  }catch(IOException e){
    roomDataValid=false;
    message_TextArea.appendText("\n抱歉，服务器无法请求刷新数据");
    throw new PleaseCloseSocketException();
  }
 }// method 'client_answer_refresh' ended

 private void client_ask_log() throws PleaseCloseSocketException {

  String message=null;
   try{
   synchronized(sender){
    io_out.writeUTF("log");
    io_out.writeUTF(userName);
   }
  }catch(IOException e){
   throw new PleaseCloseSocketException();
  }
 }// method 'client_ask_log' ended

 private void client_ask_join() throws PleaseCloseSocketException {

  String message=null;
  int ID=0;
  String subject=null;
  int index=0;

  try{
   subject=room_Choice.getSelectedItem();
   synchronized(sender){
    io_out.writeUTF("join");
    io_out.writeUTF(subject);
   }
   roomName=subject;
  }catch(IOException e){
   throw new PleaseCloseSocketException();
  }
 }// method 'client_ask_join' ended

 private void client_ask_pause() throws PleaseCloseSocketException {

  String message=null;

  try{
   synchronized(sender){
    io_out.writeUTF("pause");
   }
  }catch(IOException e){
   throw new PleaseCloseSocketException();
  }
 }// method 'client_ask_pause' ended

 private void client_ask_continue() throws PleaseCloseSocketException {

  String message=null;

  try{
   synchronized(sender){
    io_out.writeUTF("continue");
   }
  }catch(IOException e){
   throw new PleaseCloseSocketException();
  }
 }// method 'client_ask_continue' ended

 private void client_ask_newRoom() throws PleaseCloseSocketException {

  String message=null;
  String subject=null;
  int roomID=0;
  RoomData roomData=null;

  try{
   synchronized(sender){
    io_out.writeUTF("new");
    subject=subject_TextField.getText();
    io_out.writeUTF(subject);
   }
   this.roomName=subject;
  }catch(IOException e){
   throw new PleaseCloseSocketException();
  }
 }// method 'client_ask_new' ended

 private void client_ask_quit() throws PleaseCloseSocketException {

  String message=null;
  int index=0;

  try{
   synchronized(sender){
    io_out.writeUTF("quit");
   }
   if (sender!=null) {
    sender.quit();
    sender=null;
   }
  }catch(IOException e){
   throw new PleaseCloseSocketException();
  }

 }// method 'client_ask_quit' ended


 public void openSocket() throws IOException {
  s=new Socket(url.getHost(),port);
  io_in=new DataInputStream(s.getInputStream());
  io_out=new DataOutputStream(s.getOutputStream());
 }
 // method openSocket ended

 public void run() {

  String message=null;

  while(true) {
   try{
    if (s!=null) {
     commandCenter("ask_refresh",
      new DataBag("none","none",0,0,0,0,0));
    }
    while(logged){
     message=io_in.readUTF();
     commandCenter(message,new DataBag("none","none",0,0,0,0,0));
    }
    synchronized (this) {
     try{
      wait();
     }catch(Exception w){
      System.out.println(w);
     }
    }
   }catch(PleaseCloseSocketException e) {
   }catch(IOException e) {}
  }
 }// method 'run' ended

 public void addNewChoice() {

  remove(room_Choice);
  room_Choice = new java.awt.Choice();
		add(room_Choice);
		room_Choice.reshape(60,45,132,23);
		room_Choice.setFont(new Font("Dialog", Font.PLAIN, 13));
	}

 public void refreshRoomList() {

  RoomData room=null;

  if(rooms!=null) {
   addNewChoice();
   for(int i=0;i< rooms.size();i++) {
    room=(RoomData)(rooms.elementAt(i));
    room_Choice.addItem(room.roomName);
   }
   if (room_Choice.countItems()!=0) {
    room_Choice.select(rooms.getDefaultRoomName());
    refreshUserList();
   }
  }
 }//method refreshRoomData ended

 public void refreshUserList() {

  String name=null;
  RoomData room=null;
  String names[]=null;

  if (room_Choice.countItems()!=0) {
   name=room_Choice.getSelectedItem();
   room=rooms.getRoomByName(name);

   if (room!=null) {
    users_List.clear();
    names=room.getUsersName();
    if (names!=null) {
     for(int i=0;i< names.length;i++) {
      users_List.addItem(names[i]);
     }
    }
   }
  }
 }// method refreshRoomData ended

 public void printChat_Area(DataBag data) {

  String message=null;

  message=data.name+':'+data.message;
  if (!(message.trim()).endsWith("\n")) {
   message=message+'\n';
  }
  synchronized(this){
   chat_TextArea.appendText(message);
  }
 }


 public void sendText() {

  String message=null;
  DataBag data=null;

  message=chat_TextField.getText();
if ((!(message.equals("")))&&(!Character.isISOControl
  (message.charAt(0)))) {
   try{
    data=new DataBag(userName,message,0,0,0,0,0);
    commandCenter("ask_text",data);
    chat_TextField.setText("");
    printChat_Area(data);
   }catch(PleaseCloseSocketException e){
    message_TextArea.appendText("抱歉，不能发送句子");
   }
  }
 }

 synchronized public void drawBoard_Canvas(DataBag data) {

  Color color=null;
  Graphics g=null;

  color=new Color(data.color);
  g=board_Canvas.getGraphics();
  g.setColor(color);
  g.drawLine(data.x0,data.y0,data.x1,data.y1);
 }
 //To do with User Event
	synchronized void chatButton_Clicked(Event event) {
  sendText();
 }

	synchronized void chatTextField_EnterHit(Event event) {
  sendText();
	}

 //change draw color
	void colorCanvas12_MouseDown(Event event) {
 	currentColor_Canvas.setBackground(Color.black);
		currentColor_Canvas.repaint();//}}
  currentColor=Color.black;
 }

	void colorCanvas11_MouseDown(Event event) {
  currentColor_Canvas.setBackground(Color.cyan);
		currentColor_Canvas.repaint();//}}
  currentColor=Color.cyan;

	}

	void colorCanvas10_MouseDown(Event event) {
  currentColor_Canvas.setBackground(Color.blue);
		currentColor_Canvas.repaint();
  currentColor=Color.blue;
	}

	void colorCanvas9_MouseDown(Event event) {
		currentColor_Canvas.setBackground(Color.gray);
		currentColor_Canvas.repaint();//}}
  currentColor=Color.gray;

	}

	void colorCanvas8_MouseDown(Event event) {
		currentColor_Canvas.setBackground(Color.green);
		currentColor_Canvas.repaint();//}}
  currentColor=Color.green;

	}

	void colorCanvas7_MouseDown(Event event) {
		currentColor_Canvas.setBackground(Color.lightGray);
		currentColor_Canvas.repaint();//}}
  currentColor=Color.lightGray;

	}

	void colorCanvas6_MouseDown(Event event) {
		currentColor_Canvas.setBackground(Color.magenta);
		currentColor_Canvas.repaint();//}}
  currentColor=Color.magenta;

	}

	void colorCanvas5_MouseDown(Event event) {
		currentColor_Canvas.setBackground(Color.orange);
		currentColor_Canvas.repaint();//}}
  currentColor=Color.orange;

	}

	void colorCanvas4_MouseDown(Event event) {
		currentColor_Canvas.setBackground(Color.pink);
		currentColor_Canvas.repaint();//}}
  currentColor=Color.pink;

	}

	void colorCanvas3_MouseDown(Event event) {
		currentColor_Canvas.setBackground(Color.red);
		currentColor_Canvas.repaint();//}}
  currentColor=Color.red;

	}

	void colorCanvas2_MouseDown(Event event) {
		currentColor_Canvas.setBackground(Color.yellow);
		currentColor_Canvas.repaint();//}}
  currentColor=Color.yellow;

	}

	void colorCanvas1_MouseDown(Event event) {
		currentColor_Canvas.setBackground(Color.white);
		currentColor_Canvas.repaint();//}}
  currentColor=Color.white;

	}

	void boardCanvas_MouseMove(Event event) {

  x0=event.x;
  y0=event.y;
	}


 void boardCanvas_MouseDrag(Event event) {

  DataBag data=null;

  if (sender.sended) {
   x1=event.x;
   y1=event.y;
   data=new DataBag("none","none",currentColor.getRGB(),
           x0,y0,x1,y1);
   drawBoard_Canvas(data);