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

public class StudentServer
{

 // Input from the client on the socket connection
 private ObjectInputStream inputFromClient;

 // Output each Student object we receive to a flat file
 private ObjectOutputStream outputToFile;


 public static void main( String[] args ) {
   new StudentServer();
 }

 public StudentServer()
 {
   try
   {
     // Create a server socket
     ServerSocket serverSocket = new ServerSocket( 8125 );
     System.out.println( "Server started at " + new Date() );

     // Create an object output stream to write to a file
     outputToFile =
       new ObjectOutputStream( new FileOutputStream( "s.dat", true ) );

     while ( true )
     {
       // Listen for a new connection request
       Socket socket = serverSocket.accept();    // BLOCKED

       // Create an input stream from the socket
       inputFromClient = new ObjectInputStream( socket.getInputStream() );

       // Read from input
       Object object = inputFromClient.readObject();   // BLOCKED

       if ( object instanceof Student )
       {
         Student s = (Student)object;
         System.out.println( s.getId() );
       }

       // Write to the file
       outputToFile.writeObject( object );
       System.out.println( "Wrote a new student object to the file" );
     }
   }
   catch( ClassNotFoundException ex ) {
     ex.printStackTrace();
   }
   catch( IOException ex ) {
     ex.printStackTrace();
   }
   finally {
     try {
       inputFromClient.close();
       outputToFile.close();
     }
     catch ( Exception ex ) {
       ex.printStackTrace();
     }
   }
 }
}