Question

I need help with my IM (instant messaging) java program, I created the Server, Client, and Message class. I somehow can't get both the server and client to message to each other. I am at a roadblock. Here is the question below.

Create an IM (instant messaging) java program so that client and server communicate via serialized objects (e.g. of type Message). Each Message object encapsulates the name of the sender and the response typed by the sender. You may assume that the names are provided as command-line arguments to the client and server respectively.

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import java.io.Serializable;

public class Message implements Serializable
{
// instance variables - replace the example below with your own
private String name;
private String response;
  
  
public Message ()
{
this.name = null;
this.response = null;
}
  
public Message(String name, String response)
{
this.name = name;
this.response = response;
}

public String getName()
{
return name;
}
  
public String getResponse()
{
return response;
}
  
public void setName(String name)
{
this.name = name;
}
  
public void setResponse(String response){
this.response = response;
}
  
}

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

public class Server {
public static void main(String[] args) throws IOException, ClassNotFoundException{
  
if (args.length != 1) {
System.err.println("Usage: java Server <port number>");
System.exit(1);
}

int portNumber = Integer.parseInt(args[0]);

  
try (
ServerSocket serverSocket = new ServerSocket(portNumber);
Socket clientSocket = serverSocket.accept();
  
ObjectOutputStream out = new ObjectOutputStream(clientSocket.getOutputStream());
ObjectInputStream in = new ObjectInputStream(clientSocket.getInputStream());
  

) {
  
BufferedReader stdIn =
new BufferedReader(new InputStreamReader(System.in));
  
Message inMessage, outMessage;
String name;
String inResponse;
String outResponse;
  
  
System.out.println("Connection Established");
  
while ((inMessage = (Message) in.readObject()) != null) {
  

System.out.println(inMessage.getName() + " " + inMessage.getResponse());
  
  
outResponse = stdIn.readLine();
System.out.println("Server: " + outResponse);
if (outResponse != null) {
System.out.println("Server: " + outResponse);
out.writeObject(new Message("Server: ", outResponse));
out.flush();
}
  
  
}
} catch (IOException e) {
System.out.println("Exception caught when trying to listen on port "
+ portNumber + " or listening for a connection");
System.out.println(e.getMessage());
}
}
}

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

public class Client {
public static void main(String[] args) throws IOException, ClassNotFoundException {
  
if (args.length != 2) {
System.err.println(
"Usage: java EchoClient <host name> <port number>");
System.exit(1);
}

String hostName = args[0];
int portNumber = Integer.parseInt(args[1]);

try (
Socket kkSocket = new Socket(hostName, portNumber);
ObjectOutputStream out = new ObjectOutputStream(kkSocket.getOutputStream());
ObjectInputStream in = new ObjectInputStream(kkSocket.getInputStream());
) {
BufferedReader stdIn =
new BufferedReader(new InputStreamReader(System.in));

Message message = new Message();
Message inMessage;
String name;
String inResponse;
String OutResponse;
  
System.out.println("Connection Established");
  
while (((inMessage = (Message) in.readObject()) != null)) {

System.out.println("Connection Established");
System.out.println(inMessage.getName() + inMessage.getResponse());
  
  
OutResponse = stdIn.readLine();
out.writeObject(new Message("Client: ", OutResponse));
  
  
}
} catch (UnknownHostException e) {
System.err.println("Don't know about host " + hostName);
System.exit(1);
} catch (IOException e) {
System.err.println("Couldn't get I/O for the connection to " +
hostName);
System.exit(1);
}
}
}

Answer 1

//for this we have these employee class

import java.io.*;
import java.util.*;

public class Employee implements Serializable {

   private int employeeNumber;
   private String employeeName;

   Employee(int num, String name) {
      employeeNumber = num;
      employeeName= name;
   }

    public int getEmployeeNumber() {
      return employeeNumber ;
   }

   public void setEmployeeNumber(int num) {
      employeeNumber = num;
   }

   public String getEmployeeName() {
      return employeeName ;
   }

   public void setEmployeeName(String name) {
      employeeName = name;
   }
}

//for client

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

public class Client {

   public static void main(String[] arg) {
      try {
         Employee joe = new Employee(150, "Joe");

         System.out.println("employeeNumber= "
                            + joe .getEmployeeNumber());
         System.out.println("employeeName= "
                            + joe .getEmployeeName());

         Socket socketConnection = new Socket("127.0.0.1", 11111);


         ObjectOutputStream clientOutputStream = new
            ObjectOutputStream(socketConnection.getOutputStream());
         ObjectInputStream clientInputStream = new 
            ObjectInputStream(socketConnection.getInputStream());

         clientOutputStream.writeObject(joe);

         joe= (Employee)clientInputStream.readObject();

         System.out.println("employeeNumber= "
                            + joe .getEmployeeNumber());
         System.out.println("employeeName= "
                            + joe .getEmployeeName());

         clientOutputStream.close();
         clientInputStream.close();

      } catch (Exception e) {System.out.println(e); }
   }
}

//for server

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

public class Server {

   public static void main(String[] arg) {

      Employee employee = null;

      try {

         ServerSocket socketConnection = new ServerSocket(11111);

         System.out.println("Server Waiting");

         Socket pipe = socketConnection.accept();

         ObjectInputStream serverInputStream = new    
            ObjectInputStream(pipe.getInputStream());

         ObjectOutputStream serverOutputStream = new 
            ObjectOutputStream(pipe.getOutputStream());

         employee = (Employee )serverInputStream.readObject();

         employee .setEmployeeNumber(256);
         employee .setEmployeeName("John");

         serverOutputStream.writeObject(employee);

         serverInputStream.close();
         serverOutputStream.close();


      }  catch(Exception e) {System.out.println(e); 
      }
   }

}