package chapter18;

/**
 * Title:        Chapter 18, "Networking"
 * Description:  Examples for Chapter 18
 * Copyright:    Copyright (c) 2000
 * Company:      Armstrong Atlantic State University
 * @author Y. Daniel Liang
 * @version 1.0
 */

// RegistrationServer.java: The server for the applet responsible for
// writing on the server side
import java.io.*;
import java.net.*;
import javax.swing.*;
import java.awt.*;
import java.util.Date;
import chapter17.Student;

public class RegistrationServer extends JFrame
{
  private static JTextArea jtaLog;

  // The file to store the records
  private static RandomAccessFile raf = null;

  /**Main method*/
  public static void main(String[] args)
  {
    RegistrationServer server = new RegistrationServer();
  }

  public RegistrationServer()
  {
    // Create a scroll pane to hold text area
    JScrollPane scrollPane = new JScrollPane(
      jtaLog = new JTextArea());

    // Add the scroll pane to the frame
    getContentPane().add(scrollPane, BorderLayout.CENTER);

    setSize(300, 300);
    setTitle("Registration Server");
    setVisible(true);

    // Open the local file on the server side
    try
    {
      // Open the file if the file exists, create a new file
      // if the file does not exist
      raf = new RandomAccessFile("student.dat", "rw");
    }
    catch(IOException ex)
    {
      jtaLog.append(new Date() + ": Error: " + ex);
      System.exit(0);
    }

    // Establish server socket
    try
    {
      // Create a server socket
      ServerSocket serverSocket = new ServerSocket(8000);
      jtaLog.append(new Date() + ": Start a new server\n");

      // Count the number of threads started
      int count = 1;

      while (true)
      {
        // Connect to a client
        Socket socket = serverSocket.accept();
        jtaLog.append(new Date() + ": A client at " +
          socket.getInetAddress().getHostAddress() + " connected\n");

        // Start a new thread to register a client
        new RegistrationThread(socket, count++).start();
      }
    }
    catch (IOException ex)
    {
      jtaLog.append(new Date() + ": " + ex);
    }
  }

  /**Write student information to the file*/
  private synchronized static void writeToFile(Student student)
  {
    try
    {
      // Append it to "student.dat"
      raf.seek(raf.length());
      student.writeStudent(raf);

      // Display data saved
      jtaLog.append("The following info saved in the file\n");
      jtaLog.append(student.toString());
    }
    catch (Exception ex)
    {
      jtaLog.append(new Date() + ": " + ex);
    }
  }

  // Define a thread to process the client registration
  class RegistrationThread extends Thread
  {
    // The socket to serve a client
    private Socket socket;

    private int clientNo; // The thread number

    // Buffered reader to get input from the client
    private BufferedReader in;

    // Create a registration thread
    public RegistrationThread(Socket socket, int clientNo)
    {
      this.socket = socket;
      this.clientNo = clientNo;

      jtaLog.append(new Date() + ": Thread " + clientNo
        + " started\n");

      // Create an input stream to receive data from a client
      try
      {
        in = new BufferedReader
          (new InputStreamReader(socket.getInputStream()));
      }
      catch(IOException ex)
      {
        jtaLog.append(new Date() + ": " + ex);
      }
    }

    public void run()
    {
      String name;
      String street;
      String city;
      String state;
      String zip;

      try
      {
        // Receive data from the client
        name = new String(in.readLine());
        street = new String(in.readLine());
        city = new String(in.readLine());
        state = new String(in.readLine());
        zip = new String(in.readLine());

        // Create a student instance
        Student student =
          new Student(name, street, city, state, zip);

        writeToFile(student);
      }
      catch (IOException ex)
      {
        System.out.println(ex);
      }
    }
  }
}