import java.awt.BorderLayout;
import java.awt.GridLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.net.Socket;
import java.net.InetAddress;
import java.io.IOException;
import java.util.Formatter;
import java.util.Scanner;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
import javax.swing.JTextArea;
import javax.swing.JTextField;
public class Client extends JFrame implements ActionListener
{
private final JTextField fileField; // text field to input file
private final JTextArea contents; // text area to display contents
private final JPanel panel; // panel to hold components
private final JLabel label; // label to prompt user
private final JScrollPane scroller; // scroller for text area
// set up GUI, connect to server, get streams
public Client()
{
super( "File Downloader" );
label = new JLabel( "Enter file name to retrieve:" );
panel = new JPanel(); // create JPanel
panel.setLayout( new GridLayout( 1, 2, 0, 0 ) );
panel.add( label ); // add label to panel
fileField = new JTextField(); // create text field
fileField.addActionListener( this ); // add action listener
panel.add( fileField ); // add text field to panel
contents = new JTextArea(); // create text area
scroller = new JScrollPane( contents ); // add scrolling
add( panel, BorderLayout.NORTH ); // add panel to north
add( scroller ); // add scrolling text area
setSize( 400, 200 ); // set window size
setVisible( true ); // show window
} // end Client constructor // process file name entered by user
@Override
public void actionPerformed( ActionEvent event )
{
Socket connection = null; // connection to server
Scanner input = null; // input scanner
Formatter output = null; // output formatter
try // display contents of file
{
// create Socket to make connection to server
connection = new Socket( InetAddress.getLocalHost(), 5001 );
output = new Formatter( connection.getOutputStream() );
output.flush(); // flush output to send header information
input = new Scanner( connection.getInputStream() );
String fileName = event.getActionCommand() + "\n";
output.format( fileName );
output.flush(); // flush output
String inputLine = input.nextLine(); // read input line
contents.setText( inputLine ); // show input line in textarea
// if file exists, display file contents
if ( inputLine.equals( "The file is:" ) )
{
while ( input.hasNextLine() )
{
inputLine = input.nextLine(); // read a new line
contents.append( '\n' + inputLine ); // add line
} // end while
} // end if
} // end try
catch ( IOException ioException )
{
System.exit( 1 );
} // end catch
finally
{
try
{
input.close(); // close output
output.close(); // close input
connection.close(); // close connection to server
}
catch ( IOException ioException ) {
System.exit( 1 );
} // end catch
} // end finally
} // end method actionPerformed
} // end class Client
import javax.swing.JFrame;
public class ClientTest
{
public static void main( String args )
{
Client application = new Client(); // create client application
application.setDefaultCloseOperation( JFrame.EXIT_ON_CLOSE );
} // end main
} // end class ClientTest
import java.net.ServerSocket;
import java.net.Socket;
import java.io.File;
import java.io.IOException;
import java.util.Formatter;
import java.util.Scanner;
/**
*
* @author jillyoung
*/
public class Server
{
private ServerSocket server; // server socket
private Socket connection; // connection to a client
private Scanner input; // input scanner
private Formatter output; // output formatter
// constructor
public Server()
{
try
{
server = new ServerSocket( 5001, 10 ); // create ServerSocket
} // end try
catch ( IOException exception ) {
System.exit( 1 );
} // end catch
} // end Server constructor
public void runServer()
{
// loop forever, handling connections one at a time
while ( true )
handleConnection();
} // end method runServer
// accept and handle one connection
private void handleConnection()
{
try // wait for connection, get streams, read file
{
connection = server.accept(); // accept connection
output = new Formatter( connection.getOutputStream() );
output.flush(); // flush output to send header information
input = new Scanner( connection.getInputStream() );
File file = new File( input.nextLine() ); // get file name
String result; // result from checking file
// file does exist
if ( file.exists() )
{
Scanner fileInput = new Scanner( file ); // file scanner
output.format( "The file is:\n" ); // write header
output.flush(); // flush output
while ( fileInput.hasNextLine() )
{
result = fileInput.nextLine(); // read a line from file
output.format( "%s\n", result ); // output line of file
output.flush(); // flush output
} // end while
} // end if
else // file does not exist
{
result = file.getName() + " does not exist\n";
output.format( result ); // write that file does not exist
output.flush(); // flush output
} // end else
} // end try
catch( IOException ioException ) {
System.exit( 1 );
} // end catch
finally
{
try
{
output.close(); // close output
input.close(); // close input
connection.close(); // close connection to client
} // end try
catch ( IOException ioException )
{
System.exit( 1 );
} // end catch
} // end finally
} // end method runServer
} // end class Server
public class ServerTest
{
public static void main( String args )
{
Server application = new Server(); // create server application
application.runServer(); // run server
} // end main
} // end class ServerTest