J2ME:使用UDP实现聊天室

最新推荐文章于 2025-05-27 15:07:33 发布

原创最新推荐文章于 2025-05-27 15:07:33 发布 · 1.1k 阅读

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#聊天 #j2me #command #string #login #null

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本文介绍了一个基于Java ME平台的简易聊天室客户端实现方法，利用UDPDatagramConnection进行消息发送与接收，支持用户登录和退出功能。

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import java.io.DataInputStream;
import java.io.DataOutputStream;
import java.io.IOException;

import javax.microedition.io.Connector;
import javax.microedition.io.Datagram;
import javax.microedition.io.ServerSocketConnection;
import javax.microedition.io.SocketConnection;
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 client extends MIDlet implements CommandListener{
//private DataOutputStream dos=null;
    //private DataInputStream dis=null;
    //private SocketConnection sc=null;
private UDPDatagramConnection udc=null;
private Datagram ugrec=null,ugsend=null;
    private String msg=null;
    private TextField tf_msg=new TextField("输入聊天信息", "", 255,TextField.ANY);
    private TextField tf_name=new TextField("输入昵称", "", 10,TextField.ANY);
    private Command cmdSend=new Command("send",Command.OK,1);
    private Command cmdlogin=new Command("login",Command.OK,1);
    private Command cmdreturn=new Command("return",Command.BACK,1);
    private Command cmdexit=new Command("exit",Command.EXIT,1);
    private Form f_login=new Form("聊天室登陆");
    private Form f_chat=new Form("聊天室客户端");
    private Display disp;
    //private String username;
    boolean isrec=false;
public client() {
  // TODO Auto-generated constructor stub

}

protected void destroyApp(boolean arg0) throws MIDletStateChangeException {
  // TODO Auto-generated method stub

   // close();

}

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

}

protected void startApp() throws MIDletStateChangeException {
  // TODO Auto-generated method stub
  disp=Display.getDisplay(this);
  disp.setCurrent(f_login);
  f_login.append(tf_name);
  f_login.addCommand(cmdlogin);
  f_login.addCommand(cmdexit);
  f_login.setCommandListener(this);

  f_chat.append(tf_msg);
  f_chat.addCommand(cmdSend);
  f_chat.addCommand(cmdreturn);
  f_chat.setCommandListener(this);



}

public void commandAction(Command c, Displayable d) {
  // TODO Auto-generated method stub
  if(c.equals(cmdSend))
  {
   try {
    //dos.writeUTF(tf_msg.getString());
    byte[] b=tf_msg.getString().getBytes();
    ugrec=udc.newDatagram(b, b.length);
    udc.send(ugrec);
    System.out.println(b.length+"client sended");
    //dos.flush();
    tf_msg.setString(null);
    } catch (IOException e) {
    // TODO Auto-generated catch block
    e.printStackTrace();
   }
  }
  else if(c.equals(cmdlogin))
  {

   new Thread(new chatThread()).start();
   disp.setCurrent(f_chat);
  }

  else if(c.equals(cmdreturn))
  {
      close();
      disp.setCurrent(f_login);
  }
  else if(c.equals(cmdexit))
  {
   this.notifyDestroyed();
  }


}
public void close()
{ isrec=false;}

class chatThread implements Runnable
{

  public void run() {
   // TODO Auto-generated method stub

   try {
    //sc=(SocketConnection)Connector.open("socket://127.0.0.1:9999");
                udc=(UDPDatagramConnection)Connector.open("datagram://127.0.0.1:9999");
    f_login.append("本地:"+udc.getLocalAddress());
    //f_login.append("服务器地址:"+udc.getAddress());
   //dos=sc.openDataOutputStream();
   //dos.writeUTF(tf_name.getString());
    ugsend=udc.newDatagram(tf_name.getString().getBytes(), tf_name.getString().getBytes().length);
    udc.send(ugsend);
   //dis=sc.openDataInputStream();
    ugrec=udc.newDatagram(255);
    udc.receive(ugrec);
    byte[] b=ugrec.getData();
    String str=new String(b,0,ugrec.getLength());
   //f_chat.append(dis.readUTF());
    f_chat.append(str+"/n");
   isrec=true;
   while(isrec)
   {
   //msg=dis.readUTF();
    ugrec=udc.newDatagram(255);
    udc.receive(ugrec);

        b=ugrec.getData();
     msg=new String(b,0,ugrec.getLength());
     System.out.println(msg+"/n");
     f_chat.append(msg+"/n");

   }
   }catch (IOException e) {
    // TODO Auto-generated catch block
    e.printStackTrace();
   }

   }
  }

}