// Fig. 18.04: PropertiesTest.java
// Demonstrates class Properties of the java.util package.
import java.io.*;
import java.util.*;
import java.awt.*;
import java.awt.event.*;
import com.deitel.jhtp2.ch11.CloseWindowAndExit;

public class PropertiesTest extends Frame
         implements ActionListener {
   private Properties table;
   private FileInputStream input;
   private FileOutputStream output;

   private TextField propName, propVal, result;
   private TextArea display;
   private Button put, clear, getProperty, save, load;

   public PropertiesTest()
   {
      super( "Properties Test" );
      table = new Properties();
      setLayout( new FlowLayout() );

      add( new Label( "Property name (key)" ) );
      propName = new TextField( 10 );
      add( propName );

      add( new Label( "Property value" ) );
      propVal = new TextField( 10 );
      add( propVal );

      display = new TextArea( 4, 35 );
      add( display );

      put = new Button( "Put" );
      put.addActionListener( this );
      add( put );

      clear = new Button( "Clear" );
      clear.addActionListener( this );
      add( clear );

      getProperty = new Button( "Get property" );
      getProperty.addActionListener( this );
      add( getProperty );

      save = new Button( "Save" );
      save.addActionListener( this );
      add( save );

      load = new Button( "Load" );
      load.addActionListener( this );
      add( load );

      result = new TextField( 35 );
      result.setEditable( false );
      add( result );

      setSize( 275, 225 );
      setVisible( true );
   }

   public void actionPerformed( ActionEvent e )
   {
      if ( e.getSource() == put ) {
         Object val = table.put( propName.getText(),
                                 propVal.getText() );

         if ( val == null )
            showStatus( "Put: " + propName.getText() + " " +
                        propVal.getText() );
         else
            showStatus( "Put: " + propName.getText() + " " +
                        propVal.getText() + "; Replaced: " +
                        val.toString() );
      }
      else if ( e.getSource() == clear ) {
         table.clear();
         showStatus( "Table in memory cleared" );
      }
      else if ( e.getSource() == getProperty ) {
         Object val = table.getProperty( propName.getText() );
             
         if ( val != null )
            showStatus( "Get property: " + propName.getText() +
                        " " + val.toString() );
         else
            showStatus( "Get: " + propName.getText() +
                        " not in table" );
      }
      else if ( e.getSource() == save ) {
         try {
            output = new FileOutputStream( "props.dat" );
            table.save( output, "Sample Properties" );
            output.close();
         }
         catch( IOException ex ) {
            showStatus( ex.toString() );
         }
      }
      else if ( e.getSource() == load ) {
         try {
            input = new FileInputStream( "props.dat" );
            table.load( input );
            input.close();
         }
         catch( IOException ex ) {
            showStatus( ex.toString() );
         }
      }

      listProperties();
   }

   public void listProperties()
   {
      StringBuffer buf = new StringBuffer();
      String pName, pVal;

      Enumeration enum = table.propertyNames();

      while( enum.hasMoreElements() ) {
         pName = enum.nextElement().toString();
         pVal = table.getProperty( pName );
         buf.append( pName ).append( '\t' );
         buf.append( pVal ).append( '\n' );
      }

      display.setText( buf.toString() );
   }

   public void showStatus( String s )
   {
      result.setText( s );
   }

   public static void main( String args[] )
   {
      PropertiesTest p = new PropertiesTest();
      p.addWindowListener( new CloseWindowAndExit() );
   }
}