Java聊天程序，电子白板源代码二

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