Server and Client using Sockets
Are there any examples of a server and a client that use sockets, but that have send and get methods?  I'm doing this networked battleship program, almost finished, but can't get the server and clients to work.  I have made a chat program that only sends strings, but this time I need to send objects.  I'm already frustrated, so is there any source code that already has this.

Here's the code for the client... how would you modify it to allow to send objects?  Also I need to be listening for incoming objects and process them right away.













    enter code here














   

import java.net.*; 
import java.io.*; 
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;

public class SimpleChat extends JFrame 
{ 
 private Socket communicationSocket = null;
 private PrintWriter outStream = null;
 private BufferedReader inStream = null;
 private Boolean communicationContinue = true;
 private String disconnectString = "disconnect764*#$1";
 private JMenuItem disconnectItem;


 private JTextField displayLabel;
 private final Color colorValues[] = 
      { Color.black, Color.blue, Color.red, Color.green }; 

   // set up GUI
   public SimpleChat()
   {
      super( "Simple Chat" );     

      // set up File menu and its menu items
      JMenu fileMenu = new JMenu( "File" );
      fileMenu.setMnemonic( 'F' );

      // set up Activate Server menu item
      JMenuItem serverItem = new JMenuItem( "Activate Server");
      serverItem.setMnemonic( 'S' );
      fileMenu.add( serverItem );
      serverItem.addActionListener(

         new ActionListener() {  // anonymous inner class

            // display message dialog when user selects About...
            public void actionPerformed( ActionEvent event )
            {
               setUpServer();
            }
         }  // end anonymous inner class
      ); // end call to addActionListener

      // set up Activate Client menu item
      JMenuItem clientItem = new JMenuItem( "Activate Client");
      clientItem.setMnemonic( 'C' );
      fileMenu.add( clientItem );
      clientItem.addActionListener(

         new ActionListener() {  // anonymous inner class

            // display message dialog when user selects About...
            public void actionPerformed( ActionEvent event )
            {
               setUpClient();
            }
         }  // end anonymous inner class
      ); // end call to addActionListener

      // set up Activate Client menu item
      disconnectItem = new JMenuItem( "Disconnect Client/Server");
      disconnectItem.setMnemonic( 'D' );
      disconnectItem.setEnabled (false);
      fileMenu.add( disconnectItem );
      disconnectItem.addActionListener(

         new ActionListener() {  // anonymous inner class

            // display message dialog when user selects About...
            public void actionPerformed( ActionEvent event )
            {
               disconnectClientServer(true);
            }
         }  // end anonymous inner class
      ); // end call to addActionListener

      // set up About... menu item
      JMenuItem aboutItem = new JMenuItem( "About..." );
      aboutItem.setMnemonic( 'A' );
      fileMenu.add( aboutItem );
      aboutItem.addActionListener(

         new ActionListener() {  // anonymous inner class

            // display message dialog when user selects About...
            public void actionPerformed( ActionEvent event )
            {
               JOptionPane.showMessageDialog( SimpleChat.this,
                  "This is an example\nof using menus",
                  "About", JOptionPane.PLAIN_MESSAGE );
            }

         }  // end anonymous inner class

      ); // end call to addActionListener
 
      // set up Exit menu item
      JMenuItem exitItem = new JMenuItem( "Exit" );
      exitItem.setMnemonic( 'x' );
      fileMenu.add( exitItem );
      exitItem.addActionListener(

         new ActionListener() {  // anonymous inner class

            // terminate application when user clicks exitItem
            public void actionPerformed( ActionEvent event )
            {
               disconnectClientServer(true);
               System.exit( 0 );
            }

         }  // end anonymous inner class

      ); // end call to addActionListener

      // create menu bar and attach it to MenuTest window
      JMenuBar bar = new JMenuBar();  
      setJMenuBar( bar );  
      bar.add( fileMenu );    

     
      // set up label to display text
      displayLabel = new JTextField( "Sample Text", SwingConstants.CENTER );
      displayLabel.setForeground( colorValues[ 0 ] );
      displayLabel.setFont( new Font( "Serif", Font.PLAIN, 72 ) );
      displayLabel.addActionListener(

         new ActionListener() {  // anonymous inner class

            // display message dialog when user selects About...
            public void actionPerformed( ActionEvent event )
            {
               sendData();
            }
         }  // end anonymous inner class
      ); // end call to addActionListener

      getContentPane().setBackground( Color.CYAN );
      getContentPane().add( displayLabel, BorderLayout.CENTER );

      setSize( 500, 200 );
      setVisible( true );

   } // end constructor

  public static void main( String args[] )
   {
      final SimpleChat application = new SimpleChat();

      application.addWindowListener(
         new WindowAdapter() {
            public void windowClosing( WindowEvent e )
            {
               application.disconnectClientServer(true);
               System.exit( 0 );
            }
         }
        );


      //application.setDefaultCloseOperation( JFrame.EXIT_ON_CLOSE );
   }

 public void setCommunicationSocket (Socket sock)
   {
    communicationSocket = sock;
    communicationContinue = true;
    disconnectItem.setEnabled (true);
   }

 public void setOutStream (PrintWriter out)
   {
    outStream = out;
   }

 public void setInStream (BufferedReader in)
   {
    inStream = in;
   }

 public void setUpServer() 
   { 
    ServerThread st = new ServerThread (this);
    st.start();
   } 


 public  void setUpClient()
   {
    ClientThread st = new ClientThread (this);
    st.start();
   }


 public void disconnectClientServer(Boolean sendMessage)
   {
    if (communicationSocket == null)
       return;

    try {
         // shut down socket read loop
         communicationContinue = false;
         disconnectItem.setEnabled (false);

         // send notification to other end of socket
         if (sendMessage == true)
             outStream.println(disconnectString);

         // sleep to let read loop shut down
         Thread t = Thread.currentThread(); 
         try { t.sleep(500); } 
         catch  (InterruptedException ie) { return; }


         outStream.close(); 
         inStream.close(); 
         communicationSocket.close(); 
        }
    catch (IOException e) 
        { 
         System.err.println("Stream Read Failed."); 
         JOptionPane.showMessageDialog( SimpleChat.this,
                  "Disconnection Failed",
                  "SimpleChat", JOptionPane.PLAIN_MESSAGE );
         return; 
        } 
    finally
        { 
         communicationSocket = null; 
        }
   }

 public void sendData ()
   {
    if (communicationSocket != null)
       {
        String data = displayLabel.getText();
        outStream.println(data);
       }
   }

 public void getData()
   {
    String inputLine; 

    try {

         while (communicationContinue == true)
             {
              communicationSocket.setSoTimeout(100);
              //System.out.println ("Waiting for Connection");
         
              try {

                   while (((inputLine = inStream.readLine()) != null))
                       { 
                        System.out.println ("From socket: " + inputLine);
                        if (inputLine.equals(disconnectString))
                           {
                            disconnectClientServer(false);
                            return;
                           }
                        displayLabel.setText (inputLine);
                       }
                  }
              catch (SocketTimeoutException ste)
                  {
                   //System.out.println ("Timeout Occurred");
                  }
             } // end of while loop
          System.out.println ("communication is false");
        }
    catch (IOException e) 
        { 
         System.err.println("Stream Read Failed."); 
         JOptionPane.showMessageDialog( SimpleChat.this,
                  "Input Stream read failed",
                  "SimpleChat", JOptionPane.PLAIN_MESSAGE );
         return; 
        } 
   }

} 



//////////////////////////////////////////////////////////////////////
class ServerThread extends Thread
{
  private SimpleChat sc;
  private JTextField display;

  public ServerThread (SimpleChat scParam)
    {
     sc = scParam;
    }

  public void run()
    {
    ServerSocket connectionSocket = null; 

    try { 
         connectionSocket = new ServerSocket(10007); 
        } 
    catch (IOException e) 
        { 
         System.err.println("Could not listen on port: 10007."); 
         JOptionPane.showMessageDialog( sc,
                  "Could not listen on port: 10007",
                  "Server", JOptionPane.PLAIN_MESSAGE );
         return; 
        } 

    JOptionPane.showMessageDialog( sc,
                  "Server Socket is now activated",
                  "Server", JOptionPane.PLAIN_MESSAGE );

    
     Socket communicationSocket = null; 

    try { 
         communicationSocket = connectionSocket.accept(); 
        } 
    catch (IOException e) 
        { 
         System.err.println("Accept failed."); 
         JOptionPane.showMessageDialog( sc,
                  "Accept failed",
                  "Server", JOptionPane.PLAIN_MESSAGE );
         return; 
        } 

    JOptionPane.showMessageDialog( sc,
                  "Comminucation is now activated",
                  "Server", JOptionPane.PLAIN_MESSAGE );

    try {
         PrintWriter out = new PrintWriter(communicationSocket.getOutputStream(), 
                                      true); 
         BufferedReader in = new BufferedReader( 
                 new InputStreamReader( communicationSocket.getInputStream())); 

         sc.setCommunicationSocket (communicationSocket);
         sc.setOutStream (out);
         sc.setInStream (in);

         connectionSocket.close ();

         sc.getData();

        } 
    catch (IOException e) 
        { 
         System.err.println("Accept failed."); 
         JOptionPane.showMessageDialog( sc,
                  "Creation of Input//Output Streams failed",
                  "Server", JOptionPane.PLAIN_MESSAGE );
         return; 
        } 
    }
}

class ClientThread extends Thread
{
 private SimpleChat sc;

 public ClientThread (SimpleChat scParam)
   {
    sc = scParam;
   }

 public void run ()
   {
        Socket echoSocket = null;
        PrintWriter out = null;
        BufferedReader in = null;
        String ipAddress = "127.0.0.1";

        try {

            echoSocket = new Socket(ipAddress, 10007);
            out = new PrintWriter(echoSocket.getOutputStream(), true);
            in = new BufferedReader(new InputStreamReader(
                                        echoSocket.getInputStream()));
        } catch (UnknownHostException e) {
            System.err.println("Don't know about host: " + ipAddress);
            JOptionPane.showMessageDialog( sc,
                  "Don't know about host: " + ipAddress,
                  "Client", JOptionPane.PLAIN_MESSAGE );
            return;
        } catch (IOException e) {
            System.err.println("Couldn't get I/O for "
                               + "the connection to: " + ipAddress);
            JOptionPane.showMessageDialog( sc,
                  "Couldn't get I/O for the connection to: " + ipAddress,
                  "Client", JOptionPane.PLAIN_MESSAGE );
            return;
        }
        JOptionPane.showMessageDialog( sc,
                  "Comminucation is now activated",
                  "Client", JOptionPane.PLAIN_MESSAGE );

        sc.setCommunicationSocket (echoSocket);
        sc.setOutStream (out);
        sc.setInStream (in);

        sc.getData ();

    }


}





Server and Client using Sockets
===

Are there any examples of a server and a client that use sockets, but that have send and get methods?  I'm doing this networked battleship program, almost finished, but can't get the server and clients to work.  I have made a chat program that only sends strings, but this time I need to send objects.  I'm already frustrated, so is there any source code that already has this.

Here's the code for the client... how would you modify it to allow to send objects?  Also I need to be listening for incoming objects and process them right away.













    enter code here














   

import java.net.*; 
import java.io.*; 
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;

public class SimpleChat extends JFrame 
{ 
 private Socket communicationSocket = null;
 private PrintWriter outStream = null;
 private BufferedReader inStream = null;
 private Boolean communicationContinue = true;
 private String disconnectString = "disconnect764*#$1";
 private JMenuItem disconnectItem;


 private JTextField displayLabel;
 private final Color colorValues[] = 
      { Color.black, Color.blue, Color.red, Color.green }; 

   // set up GUI
   public SimpleChat()
   {
      super( "Simple Chat" );     

      // set up File menu and its menu items
      JMenu fileMenu = new JMenu( "File" );
      fileMenu.setMnemonic( 'F' );

      // set up Activate Server menu item
      JMenuItem serverItem = new JMenuItem( "Activate Server");
      serverItem.setMnemonic( 'S' );
      fileMenu.add( serverItem );
      serverItem.addActionListener(

         new ActionListener() {  // anonymous inner class

            // display message dialog when user selects About...
            public void actionPerformed( ActionEvent event )
            {
               setUpServer();
            }
         }  // end anonymous inner class
      ); // end call to addActionListener

      // set up Activate Client menu item
      JMenuItem clientItem = new JMenuItem( "Activate Client");
      clientItem.setMnemonic( 'C' );
      fileMenu.add( clientItem );
      clientItem.addActionListener(

         new ActionListener() {  // anonymous inner class

            // display message dialog when user selects About...
            public void actionPerformed( ActionEvent event )
            {
               setUpClient();
            }
         }  // end anonymous inner class
      ); // end call to addActionListener

      // set up Activate Client menu item
      disconnectItem = new JMenuItem( "Disconnect Client/Server");
      disconnectItem.setMnemonic( 'D' );
      disconnectItem.setEnabled (false);
      fileMenu.add( disconnectItem );
      disconnectItem.addActionListener(

         new ActionListener() {  // anonymous inner class

            // display message dialog when user selects About...
            public void actionPerformed( ActionEvent event )
            {
               disconnectClientServer(true);
            }
         }  // end anonymous inner class
      ); // end call to addActionListener

      // set up About... menu item
      JMenuItem aboutItem = new JMenuItem( "About..." );
      aboutItem.setMnemonic( 'A' );
      fileMenu.add( aboutItem );
      aboutItem.addActionListener(

         new ActionListener() {  // anonymous inner class

            // display message dialog when user selects About...
            public void actionPerformed( ActionEvent event )
            {
               JOptionPane.showMessageDialog( SimpleChat.this,
                  "This is an example\nof using menus",
                  "About", JOptionPane.PLAIN_MESSAGE );
            }

         }  // end anonymous inner class

      ); // end call to addActionListener
 
      // set up Exit menu item
      JMenuItem exitItem = new JMenuItem( "Exit" );
      exitItem.setMnemonic( 'x' );
      fileMenu.add( exitItem );
      exitItem.addActionListener(

         new ActionListener() {  // anonymous inner class

            // terminate application when user clicks exitItem
            public void actionPerformed( ActionEvent event )
            {
               disconnectClientServer(true);
               System.exit( 0 );
            }

         }  // end anonymous inner class

      ); // end call to addActionListener

      // create menu bar and attach it to MenuTest window
      JMenuBar bar = new JMenuBar();  
      setJMenuBar( bar );  
      bar.add( fileMenu );    

     
      // set up label to display text
      displayLabel = new JTextField( "Sample Text", SwingConstants.CENTER );
      displayLabel.setForeground( colorValues[ 0 ] );
      displayLabel.setFont( new Font( "Serif", Font.PLAIN, 72 ) );
      displayLabel.addActionListener(

         new ActionListener() {  // anonymous inner class

            // display message dialog when user selects About...
            public void actionPerformed( ActionEvent event )
            {
               sendData();
            }
         }  // end anonymous inner class
      ); // end call to addActionListener

      getContentPane().setBackground( Color.CYAN );
      getContentPane().add( displayLabel, BorderLayout.CENTER );

      setSize( 500, 200 );
      setVisible( true );

   } // end constructor

  public static void main( String args[] )
   {
      final SimpleChat application = new SimpleChat();

      application.addWindowListener(
         new WindowAdapter() {
            public void windowClosing( WindowEvent e )
            {
               application.disconnectClientServer(true);
               System.exit( 0 );
            }
         }
        );


      //application.setDefaultCloseOperation( JFrame.EXIT_ON_CLOSE );
   }

 public void setCommunicationSocket (Socket sock)
   {
    communicationSocket = sock;
    communicationContinue = true;
    disconnectItem.setEnabled (true);
   }

 public void setOutStream (PrintWriter out)
   {
    outStream = out;
   }

 public void setInStream (BufferedReader in)
   {
    inStream = in;
   }

 public void setUpServer() 
   { 
    ServerThread st = new ServerThread (this);
    st.start();
   } 


 public  void setUpClient()
   {
    ClientThread st = new ClientThread (this);
    st.start();
   }


 public void disconnectClientServer(Boolean sendMessage)
   {
    if (communicationSocket == null)
       return;

    try {
         // shut down socket read loop
         communicationContinue = false;
         disconnectItem.setEnabled (false);

         // send notification to other end of socket
         if (sendMessage == true)
             outStream.println(disconnectString);

         // sleep to let read loop shut down
         Thread t = Thread.currentThread(); 
         try { t.sleep(500); } 
         catch  (InterruptedException ie) { return; }


         outStream.close(); 
         inStream.close(); 
         communicationSocket.close(); 
        }
    catch (IOException e) 
        { 
         System.err.println("Stream Read Failed."); 
         JOptionPane.showMessageDialog( SimpleChat.this,
                  "Disconnection Failed",
                  "SimpleChat", JOptionPane.PLAIN_MESSAGE );
         return; 
        } 
    finally
        { 
         communicationSocket = null; 
        }
   }

 public void sendData ()
   {
    if (communicationSocket != null)
       {
        String data = displayLabel.getText();
        outStream.println(data);
       }
   }

 public void getData()
   {
    String inputLine; 

    try {

         while (communicationContinue == true)
             {
              communicationSocket.setSoTimeout(100);
              //System.out.println ("Waiting for Connection");
         
              try {

                   while (((inputLine = inStream.readLine()) != null))
                       { 
                        System.out.println ("From socket: " + inputLine);
                        if (inputLine.equals(disconnectString))
                           {
                            disconnectClientServer(false);
                            return;
                           }
                        displayLabel.setText (inputLine);
                       }
                  }
              catch (SocketTimeoutException ste)
                  {
                   //System.out.println ("Timeout Occurred");
                  }
             } // end of while loop
          System.out.println ("communication is false");
        }
    catch (IOException e) 
        { 
         System.err.println("Stream Read Failed."); 
         JOptionPane.showMessageDialog( SimpleChat.this,
                  "Input Stream read failed",
                  "SimpleChat", JOptionPane.PLAIN_MESSAGE );
         return; 
        } 
   }

} 



//////////////////////////////////////////////////////////////////////
class ServerThread extends Thread
{
  private SimpleChat sc;
  private JTextField display;

  public ServerThread (SimpleChat scParam)
    {
     sc = scParam;
    }

  public void run()
    {
    ServerSocket connectionSocket = null; 

    try { 
         connectionSocket = new ServerSocket(10007); 
        } 
    catch (IOException e) 
        { 
         System.err.println("Could not listen on port: 10007."); 
         JOptionPane.showMessageDialog( sc,
                  "Could not listen on port: 10007",
                  "Server", JOptionPane.PLAIN_MESSAGE );
         return; 
        } 

    JOptionPane.showMessageDialog( sc,
                  "Server Socket is now activated",
                  "Server", JOptionPane.PLAIN_MESSAGE );

    
     Socket communicationSocket = null; 

    try { 
         communicationSocket = connectionSocket.accept(); 
        } 
    catch (IOException e) 
        { 
         System.err.println("Accept failed."); 
         JOptionPane.showMessageDialog( sc,
                  "Accept failed",
                  "Server", JOptionPane.PLAIN_MESSAGE );
         return; 
        } 

    JOptionPane.showMessageDialog( sc,
                  "Comminucation is now activated",
                  "Server", JOptionPane.PLAIN_MESSAGE );

    try {
         PrintWriter out = new PrintWriter(communicationSocket.getOutputStream(), 
                                      true); 
         BufferedReader in = new BufferedReader( 
                 new InputStreamReader( communicationSocket.getInputStream())); 

         sc.setCommunicationSocket (communicationSocket);
         sc.setOutStream (out);
         sc.setInStream (in);

         connectionSocket.close ();

         sc.getData();

        } 
    catch (IOException e) 
        { 
         System.err.println("Accept failed."); 
         JOptionPane.showMessageDialog( sc,
                  "Creation of Input//Output Streams failed",
                  "Server", JOptionPane.PLAIN_MESSAGE );
         return; 
        } 
    }
}

class ClientThread extends Thread
{
 private SimpleChat sc;

 public ClientThread (SimpleChat scParam)
   {
    sc = scParam;
   }

 public void run ()
   {
        Socket echoSocket = null;
        PrintWriter out = null;
        BufferedReader in = null;
        String ipAddress = "127.0.0.1";

        try {

            echoSocket = new Socket(ipAddress, 10007);
            out = new PrintWriter(echoSocket.getOutputStream(), true);
            in = new BufferedReader(new InputStreamReader(
                                        echoSocket.getInputStream()));
        } catch (UnknownHostException e) {
            System.err.println("Don't know about host: " + ipAddress);
            JOptionPane.showMessageDialog( sc,
                  "Don't know about host: " + ipAddress,
                  "Client", JOptionPane.PLAIN_MESSAGE );
            return;
        } catch (IOException e) {
            System.err.println("Couldn't get I/O for "
                               + "the connection to: " + ipAddress);
            JOptionPane.showMessageDialog( sc,
                  "Couldn't get I/O for the connection to: " + ipAddress,
                  "Client", JOptionPane.PLAIN_MESSAGE );
            return;
        }
        JOptionPane.showMessageDialog( sc,
                  "Comminucation is now activated",
                  "Client", JOptionPane.PLAIN_MESSAGE );

        sc.setCommunicationSocket (echoSocket);
        sc.setOutStream (out);
        sc.setInStream (in);

        sc.getData ();

    }


}




