Question

**这是两个同行之间简单的聊天代码。根据我的说法，代码执行它应该具有的功能，但是我遇到了解决此SocketException错误的困难。这段代码工作正常，直到我做了最后的修改。现在我发现很难追踪错误。

import java.awt.BorderLayout;
import java.awt.FlowLayout;
import java.awt.GridLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.io.*;
import java.util.*;
import java.net.*;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JTextArea;
import javax.swing.JTextField;

public class UDPchat extends Thread implements ActionListener
{
    JFrame f;
    JPanel p;
    JTextField text;
    JButton b;
    JTextArea ta;
    private final static String newline = "\n";
    private final static BufferedReader in = new BufferedReader(new InputStreamReader(System.in));

    int porttor=7777; // port to send/receive datagrams on
    //int porttos=5555;
    String remoteIPaddress= ("127.0.0.1");      // IP to send datagrams

    public UDPchat() throws Exception
    {
        start();      // start thread to receive and display datagrams
        f=new JFrame("CHAT WINDOW");
        p= new JPanel();
        text = new JTextField();
        text.setColumns(25);

        b = new JButton("SEND");

        b.addActionListener(this);

        ta = new JTextArea("Chat messages",20,50);

        ta.setEditable(false);

        f.setLayout(new FlowLayout());

        p.add(text,BorderLayout.NORTH);

        p.add(b,BorderLayout.SOUTH);

        f.setLayout(new BorderLayout());

        f.add(ta,BorderLayout.NORTH);

        f.add(p,BorderLayout.SOUTH);

        f.setSize(400, 400);

        f.setVisible(true);
    }

    @Override

    public void actionPerformed(ActionEvent e)
    {

        try
        {

            String s = text.getText();  // read a String

            text.setText(" ");

            ta.append(newline);

            ta.append(s);

            //System.out.println("Sending to " + remoteIPaddress + " socket " + port + " data: " + s);

            byte[] data = s.getBytes();  // convert to byte array

            DatagramSocket theSocket = new DatagramSocket();  // create datagram socket and the datagram

            DatagramPacket   theOutput = new DatagramPacket(data, data.length, InetAddress.getLocalHost(), 5555);

            theSocket.send(theOutput);     

        }

        catch(Exception et)
        {

            System.out.println("Error sending datagram" + et);

        }

    }

    // thread run method, receives datagram and display contents as a string
    public void run()                
    {

        try
        {

            // open DatagramSocket to receive 

            DatagramSocket ds = new DatagramSocket(7777);

            // loop forever reading datagrams from the DatagramSocket

            while (true)
            {

                byte[] buffer = new byte[65507];  // array to put datagrams in

                DatagramPacket dp = new DatagramPacket(buffer, buffer.length);  // DatagramPacket to hold the datagram

                try {

                    ds.receive(dp);

                } catch (IOException e) {

                    // TODO Auto-generated catch block

                    System.err.println("chat error2 " + e);

                }   // wait for next datagram

                String s = new String(dp.getData(),0,dp.getLength()); // get contents as a String

                System.out.println("UDP datagram length " + s.length()+ "  from IP " + dp.getAddress() + " received: " + s );

                ta.append(newline);

                ta.append(s);

            }

        }

        catch (SocketException se)
        {

             System.err.println("chat error1 " + se);

        }

        //catch (IOException se) {System.err.println("chat error2 " + se);}

        //System.exit(1);   // exit on error

    }

    public static void main(String args[]) throws Exception
    {

        UDPchat c=new UDPchat();

    }

}

Answer 1

你确定其他应用程序绑定到该端口（7777）吗？您是否尝试过具有相同结果的其他端口？

另外请确保没有防病毒或防火墙运行，这也可以拒绝绑定端口。

Answer 2

检查您在代码中制作两种类型的DatagramSockets，尝试提供相同的7777端口。你的actionPerformed（）方法中有一个：

DatagramSocket theSocket = new DatagramSocket();  // create datagram socket and the datagram

和你运行方法中的那个：

// open DatagramSocket to receive 

DatagramSocket ds = new DatagramSocket(7777);

Upper构造函数正在创建一个数据报套接字并将其绑定到本地主机上的任何可用端口，第二个构造函数正在尝试访问端口7777.尝试使用相同的端口号初始化它们，这将对事情进行排序你。

希望这可能会有所帮助。

此致

查找隐藏的错误导致java.net.SocketException：无法识别的Windows套接字错误：0：无法绑定

2 个答案: