AWS EC2 Linux 客户端代码未与 Windows Java 上的服务器连接

Question

public class Client {
    
    private Socket socket;
    private DataOutputStream out     = null; 
    private Writer writer;


    public Client(Writer writer) { // get all stats in the client class 
        this.writer = writer;
    }


    public void connectToServer() 
    { 
    
        // establish a connection 
    
        try
        { 
            System.out.println("Connecting...");
            socket = new Socket("39.32.42.65", 4003); 
        
        
            System.out.println("Connected"); 
  
  
            // sends output to the socket 
            out    = new DataOutputStream(socket.getOutputStream()); 
        }
        catch(UnknownHostException u) 
        { 
            System.out.println(u); 
        } 
        catch(IOException i) 
        { 
            System.out.println(i); 
        } 


            try
            { 
                this.writer.transferStats(out); // send all stats to back end server
                out.writeUTF("Over"); // finish sending 
            } 
            catch(IOException i) 
            { 
                System.out.println(i); 
            } 

        try
        { 
            out.close(); 
            socket.close(); 
        } 
        catch(IOException i) 
        { 
            System.out.println(i); 
        } 
    } 

}

This is client code above ^

package com.clxpr.demo;
import java.io.BufferedInputStream;
import java.io.DataInputStream;
import java.io.IOException;
import java.net.ServerSocket;
import java.net.Socket;
import org.springframework.context.ConfigurableApplicationContext;
import com.clxpr.demo.service.CpuDataService;
import com.clxpr.demo.service.DiskDataService;
import com.clxpr.demo.service.IoDataService;
import com.clxpr.demo.service.MemDataService;
import com.clxpr.demo.service.PidDataService;
import com.clxpr.demo.service.PidSchedDataService;
import com.clxpr.demo.service.ResourceDataService;
import com.clxpr.demo.service.ResourceService;

public class LinuxListener implements Runnable {

    private ConfigurableApplicationContext springContext;
    private ServerSocket server;
    private ResourceService resourceServ;
    private ResourceDataService resourceDataServ;
    private CpuDataService cpuDataServ;
    private DiskDataService diskDataServ;
    private IoDataService ioDataServ;
    private MemDataService memDataServ;
    private PidDataService pidDataServ;
    private PidSchedDataService pidSchedDataServ;

    // Constructor to get objects of services managed by java spring 
    public LinuxListener(ConfigurableApplicationContext springContext) throws IOException {
        // TODO Auto-generated constructor stub
        this.springContext=springContext;
        this.resourceServ=springContext.getBean("ResourceService",ResourceService.class);
        this.resourceDataServ=springContext.getBean("ResourceDataService",ResourceDataService.class);
        this.cpuDataServ = springContext.getBean("CpuDataService",CpuDataService.class);
        this.diskDataServ = springContext.getBean("DiskDataService",DiskDataService.class);
        this.ioDataServ = springContext.getBean("IoDataService",IoDataService.class);
        this.pidDataServ = springContext.getBean("PidDataService",PidDataService.class);
        this.pidSchedDataServ = springContext.getBean("PidSchedDataService",PidSchedDataService.class);
        this.memDataServ = springContext.getBean("MemDataService",MemDataService.class);
        server = new ServerSocket(4003);    // create server socket for client to connect to
        
    }
    
    public ConfigurableApplicationContext getContext() {
        return this.springContext;
    }
    
    

    @Override
    public void run() {
        int usrId = 1;
        while(true) {
            try { 
                    
                    System.out.println("Server started"); 
          
                    System.out.println("Waiting for a client ..."); 
          
                    Socket socket = server.accept(); 
                    System.out.println("Client accepted"); 
          
                    // takes input from the client socket 
                    DataInputStream in = new DataInputStream( 
                        new BufferedInputStream(socket.getInputStream())); 
                    Thread t = new ClientHandler(socket,in,this.resourceServ,this.resourceDataServ,this.cpuDataServ,this.diskDataServ,
                            this.ioDataServ,this.memDataServ,this.pidDataServ,this.pidSchedDataServ, usrId);
                    t.start();
                   
            } 
            catch(IOException i) 
            { 
                System.out.println(i); 
            }
            usrId++;
        }
    }
    

}

this is server code above ^

The ip given is the public ip i have. The client code is on AWS ec2 instance Linux env It is not connecting with the server. It connects when i run both of them on same network. I changed the settings on my router to enable ports 4000 to 4005 under NAT.

Answer 1

You might want to check your VPC network ACLs, especially the outbound part.

If I get that clearly, you forwarded ports 4000 to 4005.

Are you sure you bound your server to your router IP?

Is there some kind of firewall on your router that might block external ips?

Last but not least, have you considered that maybe your Windows Firewall is preventing you from foreign requests?

Kind regards