Question

我正在尝试在服务器和客户端之间创建双向通信，其中双方（服务器和客户端）可以相互发送消息，而无需等待另一方响应。为此，我创建了一个单独的线程来监听套接字并在屏幕上打印传入的消息。这是真正的问题：我第一次编译和运行服务器和客户端时，我运行程序后一切正常，我从服务器和客户端收到此错误消息。

java.net.ConnectException: Connection refused (Connection refused)
at java.net.PlainSocketImpl.socketConnect(Native Method)
at java.net.AbstractPlainSocketImpl.doConnect(AbstractPlainSocketImpl.java:350)
at java.net.AbstractPlainSocketImpl.connectToAddress(AbstractPlainSocketImpl.java:206)
at java.net.AbstractPlainSocketImpl.connect(AbstractPlainSocketImpl.java:188)
at java.net.SocksSocketImpl.connect(SocksSocketImpl.java:392)
at java.net.Socket.connect(Socket.java:589)
at java.net.Socket.connect(Socket.java:538)
at java.net.Socket.<init>(Socket.java:434)
at java.net.Socket.<init>(Socket.java:211)
at Build.work(c.java:18)
at s.main(s.java:83)

Exception in thread "Thread-0" Exception in thread "main" java.lang.NullPointerException
at Build.run(c.java:59)
at java.lang.Thread.run(Thread.java:748)

java.lang.NullPointerException
at Build.speak(c.java:35)
at c.main(c.java:85)

服务器

import java.net.*;
import java.io.*;

class Build implements Runnable
{
    int  port = 3500;
    String input1;
    ServerSocket server;
    Socket socket;
    DataInputStream in;
    DataOutputStream out;
    Console reader;

    public void work()
    {
        try
        {
            server = new ServerSocket(port);
            socket = server.accept();
            in = new DataInputStream(socket.getInputStream());
            out = new DataOutputStream(socket.getOutputStream());
            reader = System.console();
        }

        catch(IOException e){
        e.printStackTrace();}
    }

    public void speak()
    {
        try
        {
            while(true)
            {
                input1 = reader.readLine();
                out.writeUTF(input1);
                if(input1.equals("stop"))
                {
                    in.close();
                    out.close();
                    socket.close();
                    server.close();
                    System.exit(0);
                }               
            }
        }
        catch (IOException e){
        e.printStackTrace();}
    }

    public void run()
    {
        String input2;

        try
        {
            while(true)
            {
                input2 = in.readUTF();
                System.out.println(input2);
                if(input2.equals("stop"))
                {
                    in.close();
                    out.close();
                    socket.close();
                    server.close();
                    System.exit(0);
                }
             }
         }
        catch(IOException e){
        e.printStackTrace();}
     }
}

public class server
{
    public static void main(String[]args)
    {
        Build object = new Build();
        object.work();
        Thread t1 = new Thread(object);
        t1.start();
        object.speak();
    }
}

客户端

import java.net.*;
import java.io.*;

class Build implements Runnable
{
    String ip = "127.0.0.1";
    int  port = 3500;
    String input1;
    Socket socket;
    DataInputStream in;
    DataOutputStream out;
    Console reader;

    public void work()
    {
        try
        {
            socket = new Socket(ip, port);
            in = new DataInputStream(socket.getInputStream());
            out = new DataOutputStream(socket.getOutputStream());
            reader = System.console();
        }

        catch(IOException e){
        e.printStackTrace();}
    }

    public void speak()
    {
        try
        {
            while(true)
            { 
                input1 = reader.readLine();
                out.writeUTF(input1);
                if(input1.equals("stop"))
                {
                    in.close();
                    out.close();
                    socket.close();
                    System.exit(0);
                 }              
             }
         }
         catch (IOException e){
         e.printStackTrace();}
     }

     public void run()
     {
         String input2;

         try
         {
             while(true)
             {
                 input2 = in.readUTF();
                 System.out.println(input2);
                 if(input2.equals("stop"))
                 {
                     in.close();
                     out.close();
                     socket.close();
                     System.exit(0);
                 }
              }
         }
         catch(IOException e){
         e.printStackTrace();}
     }

}

public class client
{
    public static void main(String[]args)
    {
        Build object = new Build();
        object.work();
        Thread t1 = new Thread(object);
        t1.start();
        object.speak();
    }
}

Answer 1

这里没有服务器。服务器将创建public override void CommitTransaction() { this.CollectEventsData(); base.CommitTransaction(); this.RaiseEvents(false); }，然后开始调用ServerSocket。

你在这里只有两个客户。

您可能会在accept()和readUTF()之间感到困惑。 readLime()只能读取readUTF()撰写的数据，而writeUTF()则无法读取数据。

Java套接字编程，双向通信

1 个答案: