ObjectInputStream not reading my object via networking

**L19htn1n9** · 06-27-2012, 12:45 AM

My problem is that some how the object that i send from the server to the client does not get to the client side, or the client does not read it, String messages get read withouth a problem, but when i send a ArrayList it just does not read it. Here is my server code:

Java Code:

package server2;

import java.awt.Color;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.io.EOFException;
import java.io.IOException;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import java.net.*;
import java.util.ArrayList;

import javax.swing.JTextArea;
import javax.swing.Timer;

public class Connection implements Runnable ,ActionListener
{

	private Socket connection;
	private ObjectOutputStream output;
	private ObjectInputStream input;
	private Server server;
	private String name;
	private PlayerData pd;
	private Timer autoSend;
	
	public Connection(Socket connection, JTextArea chatWindow, Server server)
	{
		this.connection = connection;
		this.server = server;
		this.autoSend = new Timer(50, this);
	}
	
	public void run()
	{
		try
		{
			setupStreams();
			whileChatting();
		}
		catch(EOFException eofEx)
		{}
		catch (IOException e)
		{
			e.printStackTrace();
			closeRunning();
		}
		finally
		{
			closeRunning();
		}
	}
	
	//get stream to send and recieve data
		private void setupStreams() throws IOException
		{
			output = new ObjectOutputStream(connection.getOutputStream());
			output.flush();
			output.reset();
			
			input = new ObjectInputStream(connection.getInputStream());
		}
		
		//during the chat conversation
		public void whileChatting() throws IOException
		{
			try
			{
				name = (String) input.readObject();
				this.server.addConnection(this.name, this);
				this.autoSend.start();
				
				//here we make a playerdata object
				pd = new PlayerData(10, 10, 20, Color.green, name);
			} catch (ClassNotFoundException e)
			{
				e.printStackTrace();
			}
			
			String message = " You are now connected! ";
			do
			{
				//have a conversation
				try
				{
					message = (String) input.readObject();
					if(message.substring(0, 1).equals("m"))//we want to move the character
					{
						String values = message.substring(0);
						int index = values.indexOf(',');
						String valueX = values.substring(0, index);
						String valueY = values.substring(index + 1);
						System.out.println("X = " + valueX + "| Y = " + valueY);
					}
				}
				catch(ClassNotFoundException CNFEx)
				{}
			}
			while(!message.equals("CLIENT - END"));
		}
		
		//close streams and sockets after you are done chatting
		private void closeRunning()
		{
			try
			{
				this.server.removeConnection(this.name, this);
				this.autoSend.stop();
				output.close();
				input.close();
				connection.close();
			}
			catch(IOException ex)
			{
				ex.printStackTrace();
			}
		}
		
		//send a message to client
		private void sendMessage(String message)
		{
			try
			{
				output.writeObject("SERVER - " + message);
				output.flush();
			}
			catch(IOException ex)
			{
				//cant send the message
			}
		}
		
		private void sendMessage(ArrayList<PlayerData> pl)
		{
			try
			{
				output.writeObject(pl);
				output.flush();
				System.out.println("Sending info");
			}
			catch(IOException ex)
			{
				//cant send the message
				System.out.println("cant send: " + ex);
			}
		}

		public PlayerData getPd()
		{
			return pd;
		}

		public void setPd(PlayerData pd)
		{
			this.pd = pd;
		}

		@Override
		public void actionPerformed(ActionEvent arg0)
		{
			this.sendGeneralData();
		}
		
		public void sendGeneralData()
		{
			ArrayList<PlayerData> pl = new ArrayList<PlayerData>();
			ArrayList<Connection> cl = this.server.getConnectionList();
			for(Connection c: cl)
			{
				pl.add(c.getPd());
			}
			this.sendMessage(pl);
		}

}

and my client:

Java Code:

package client2;

import java.io.*;
import java.net.*;
import java.util.ArrayList;

import javax.swing.*;

@SuppressWarnings("serial")
public class Client extends JFrame
{
	private ObjectOutputStream output;
	private ObjectInputStream input;
	private String message = "";
	private String serverIP;
	private Socket connection;
	private String name= "";
	private ClientPanel panel;
	
	//constructor
	public Client(String host)
	{
		this.setTitle("Client F-IM");
		this.name = JOptionPane.showInputDialog(null, "Wat is je naam?");
		this.serverIP = host;
		this.setSize(800, 600);
		
		this.panel = new ClientPanel();
		this.add(this.panel);
		
		this.setLocationRelativeTo(null);
		this.setVisible(true);
	}
	
	//connect to server
	public void startRunning()
	{
		try
		{
			connectToServer();
			setupStreams();
			whileChatting();
		}
		catch(EOFException EOFEx)
		{}
		catch(IOException ex)
		{
			ex.printStackTrace();
		}
		finally
		{
			closeRunning();
		}
	}
	
	//connect to server
	private void connectToServer() throws IOException
	{
		connection = new Socket(InetAddress.getByName(serverIP), 6789);
	}
	
	//set up streams to send and recieve messages
	private void setupStreams() throws IOException
	{
		output = new ObjectOutputStream(connection.getOutputStream());
		output.flush();
		input = new ObjectInputStream(connection.getInputStream());
		//send the basic data
		this.sendName(name);
	}
	
	private void sendName(String name2)
	{
		try
		{
			output.writeObject(name2);
			output.flush();
		}
		catch(IOException ex)
		{
			
		}
	}

	//while chatting with server
	@SuppressWarnings("unchecked")
	private void whileChatting() throws IOException
	{
		//hier ontvangen we alle data
		this.sendData("m10,500");
		do
		{
			try
			{
				//message = (String) input.readObject();
				//System.out.println(message);
				
				ArrayList<PlayerData>  playerList = (ArrayList<PlayerData>) input.readObject();
				System.out.println("recieved player data");
				this.panel.drawPlayers(playerList);	
			}
			catch(ClassNotFoundException ex)
			{
				//class not found
			}
		}
		while(!message.equals(name + " - END"));
	}
	
	//close the streams and sockets
	private void closeRunning()
	{		
		try
		{
			output.close();
			input.close();
			connection.close();
		}
		catch(IOException ex)
		{
			ex.printStackTrace();
		}
	}
	
	//send messages to server
	private void sendData(String message)
	{
		try
		{
			output.writeObject(message);
			output.flush();
		}
		catch(IOException ex)
		{
			
		}
	}
}

I hope you guys can help me with this.

**Norm** · 06-27-2012, 02:36 AM

it just does not read it.

Can you explain what happens and post any error messages?

The posted code does not compile because of missing classes. Can you make a small program that compiles, executes and shows the problem?

**L19htn1n9** · 06-27-2012, 09:07 AM

**Tolls** · 06-27-2012, 10:06 AM

Java Code:

catch(ClassNotFoundException ex)
{                 //class not found             }

and

Java Code:

catch(IOException ex)
{                       }

You're eating exceptions all over the place.

**L19htn1n9** · 06-27-2012, 10:21 AM

that is not the problem right now, the program is not finished, but the point is that the cleint does not recieve the object

**L19htn1n9** · 06-27-2012, 10:23 AM

I added a System.out.println to the client class not found exception when recieving data, and it seems that the exception is thrown, this is the error
class not found: server2.PlayerData
so somehow i need to find a way to import the PlayerData class from my server application