Frame与java.net.*；问题

Question

用java做一个1对1聊天，我用Frame做，一直抛出个问题
基本是照抄例题的，烦劳各位大虾看看package network;import java.awt.Button;
import java.awt.FlowLayout;
import java.awt.Frame;
import java.awt.TextArea;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.WindowAdapter;
import java.awt.event.WindowEvent;
import java.net.DatagramPacket;
import java.net.DatagramSocket;
import java.net.InetAddress;import javax.swing.Box;class Client2 extends Frame implements ActionListener,Runnable{
private TextArea receive;
private TextArea sendtext;
private Button send;

Client2(){
super("网络聊天2");

send=new Button("发送");
receive=new TextArea(8,35);
sendtext=new TextArea(3,20);
receive.setEditable(false);
send.addActionListener(this);

this.setVisible(true);
this.setBounds(100,100,300,260);
this.setResizable(false);
this.setLayout(new FlowLayout());
this.add(getPanel());
this.addWindowListener(new WindowAdapter(){
public void windowClosing(WindowEvent e){
System.exit(0);
}
});

Thread t=new Thread(this);
t.start();
}

private Box getPanel(){
Box b0,b1;
b1=Box.createHorizontalBox();
b1.add(sendtext);
b1.add(Box.createHorizontalStrut(10));
b1.add(send);
b0=Box.createVerticalBox();
b0.add(receive);
b0.add(Box.createVerticalStrut(8));
b0.add(b1);
return b0;
} @Override
public void actionPerformed(ActionEvent e) {
receive.append(sendtext.getText()+"\n");
// TODO Auto-generated method stub
byte buffer[]=sendtext.getText().trim().getBytes();
try{
InetAddress add=InetAddress.getByName("127.0.0.1");
DatagramPacket data=new DatagramPacket(buffer,buffer.length,add,666);///////目标端口号
DatagramSocket mail=new DatagramSocket();
mail.send(data);
}catch(Exception e1){System.out.println("send");}
}

public void run(){
DatagramPacket pack=null;
DatagramSocket mail=null;
byte data[]=new byte[8192];
try{
pack=new DatagramPacket(data,data.length);
mail=new DatagramSocket(888); ////////本地端口号
}catch(Exception e){System.out.println("run1");}
while(true){
if(mail==null) 
break;
else
try{System.out.println("run20");
mail.receive(pack);System.out.println("run21");////就是这一行一直没执行
String msg=new String(pack.getData(),0,pack.getLength());System.out.println("run22");
receive.append(msg);System.out.println("run23");
}catch(Exception e){System.out.println("run2");break;}
}
}
}

Answer 1

   DatagramPacket data=new DatagramPacket(buffer,buffer.length,add,666);///////目标端口号new DatagramSocket(888)// 两个端口应该一样。如：9999

Answer 2

这是用一台模拟两个主机，A主机端口号888，B主机端口号666。代码一样，只是端口号相对应而且我也试过，照样是这样try{System.out.println("run20");
                    mail.receive(pack);System.out.println("run21");////就是这一行一直没执行
                    String msg=new String(pack.getData(),0,pack.getLength());System.out.println("run22");
                    receive.append(msg);System.out.println("run23");
                }catch(Exception e){System.out.println("run2");break;}

Answer 3

试试这样import java.awt.Button;
import java.awt.FlowLayout;
import java.awt.Frame;
import java.awt.TextArea;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.WindowAdapter;
import java.awt.event.WindowEvent;
import java.net.DatagramPacket;
import java.net.DatagramSocket;
import java.net.InetAddress;import javax.swing.Box;class Client2 extends Frame implements ActionListener,Runnable{
    private TextArea receive;
    private TextArea sendtext;
    private Button send;
    
    Client2(){
        super("网络聊天2");
        
        send=new Button("发送");
        receive=new TextArea(8,35);
        sendtext=new TextArea(3,20);
        receive.setEditable(false);
        send.addActionListener(this);
        
        this.setVisible(true);
        this.setBounds(100,100,300,260);
        this.setResizable(false);
        this.setLayout(new FlowLayout());
        this.add(getPanel());
        this.addWindowListener(new WindowAdapter(){
            public void windowClosing(WindowEvent e){
                System.exit(0);
            }
        });
        
        Thread t=new Thread(this);
        t.start();
    }
    
    private Box getPanel(){
        Box b0,b1;
        b1=Box.createHorizontalBox();
        b1.add(sendtext);
        b1.add(Box.createHorizontalStrut(10));
        b1.add(send);
        b0=Box.createVerticalBox();
        b0.add(receive);
        b0.add(Box.createVerticalStrut(8));
        b0.add(b1);
        return b0;
    }    @Override
    public void actionPerformed(ActionEvent e) {
        receive.append(sendtext.getText()+"\n");
        // TODO Auto-generated method stub
        byte buffer[]=sendtext.getText().trim().getBytes();
        try{
            InetAddress add;
add = InetAddress.getByName("localhost");
            DatagramPacket data=new DatagramPacket(buffer,buffer.length,add,888);///////目标端口号
            DatagramSocket mail=new DatagramSocket();
            mail.send(data);
        }catch(Exception e1){System.out.println("send");}
    }
    
    public void run(){
        DatagramPacket pack=null;
        DatagramSocket mail=null;
        byte data[]=new byte[8192];
        try{
            pack=new DatagramPacket(data,data.length);
            mail=new DatagramSocket(888); ////////本地端口号
        }catch(Exception e){System.out.println("run1");}
        while(true){
            if(mail==null) 
                break;
            else
                try{System.out.println("run20");
                    mail.receive(pack);System.out.println("run21");////就是这一行一直没执行
                    String msg=new String(pack.getData(),0,pack.getLength());System.out.println("run22");
                    receive.append(msg);System.out.println("run23");
                }catch(Exception e){System.out.println("run2");break;}
        }
    }
}
public class ChatRoom {
public static void main(String [] args) {
Client2 client = new Client2();
client.run();
}
}端口号都要改为888，主机地址用localhost

Answer 4

端口号一定要一致。如果端口号不一致了。程序就无法正常的发送到指定的地址了。
你客户端的IP一定要是服务器的IP。

Answer 5

端口号改成一样的也是同样的问题
mail.receive(pack);System.out.println("run21");////就是这一行一直没执行