chatservermidlet.java

这是郭克华老师的J2ME视频的源代码

package example;

import java.util.Vector;

import javax.microedition.io.Connector;
import javax.microedition.io.Datagram;
import javax.microedition.io.UDPDatagramConnection;
import javax.microedition.lcdui.Command;
import javax.microedition.lcdui.CommandListener;
import javax.microedition.lcdui.Display;
import javax.microedition.lcdui.Displayable;
import javax.microedition.lcdui.Form;
import javax.microedition.lcdui.TextField;
import javax.microedition.midlet.MIDlet;
import javax.microedition.midlet.MIDletStateChangeException;

public class ChatServerMIDlet extends MIDlet implements CommandListener,Runnable{
	private TextField tfMsg = new TextField("输入聊天信息","",255,TextField.ANY);
	private Command cmdSend = new Command("发送",Command.SCREEN,1);	
	private Form frmChat = new Form("聊天界面");
	private Display display;
	
	private UDPDatagramConnection udc = null;
	private final int MAX = 255;
	private String address;
	
	protected void startApp() throws MIDletStateChangeException {
		display = Display.getDisplay(this);
		display.setCurrent(frmChat);
		frmChat.addCommand(cmdSend);
		frmChat.append(tfMsg);	
		frmChat.setCommandListener(this);
		try{
			udc = (UDPDatagramConnection)Connector.open("datagram://:9999");
			new Thread(this).start();
		}catch(Exception ex){
			ex.printStackTrace();
		}
	}

	public void commandAction(Command c,Displayable d){
		if(c==cmdSend){//发送
			String msg = tfMsg.getString();
			try{
				Datagram dg = udc.newDatagram(msg.getBytes(), msg.getBytes().length);
				dg.setAddress(address);
				udc.send(dg);
			}catch(Exception ex){
				ex.printStackTrace();
			}		
			
		}
	}
	public void run(){
		while(true){
			try{
				Datagram dg = udc.newDatagram(MAX);
				udc.receive(dg);		
				address = dg.getAddress();
				String msg = new String(dg.getData(),0,dg.getLength());
				frmChat.append(msg + "\n");
			}catch(Exception ex){
				ex.printStackTrace();
			}
			
		}
	}
	protected void destroyApp(boolean arg0) throws MIDletStateChangeException {
		// TODO Auto-generated method stub

	}

	protected void pauseApp() {
		// TODO Auto-generated method stub

	}
	

}