How do I display and parse a date?

Created Dec 31, 2000

Joe Sam Shirah

The Java I18N way is to use a DateFormat. While SimpleDateFormat, which is generally returned, creates a large number of objects, it is locale aware and will handle most of your needs. The following sample code initially creates a java.sql.Date object and formats it for the default locale. An initial actionPerformed call additionally formats/displays it for a German locale and also displays the resulting java.sql.Date in standard escape format. Other dates can be entered and parsed after the initial display.


//  JDFDP.java - Display and Parse java.sql.Date

import java.sql.*;
import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
import java.text.*;
import java.util.*;

public class JDFDP extends JFrame
                   implements ActionListener,
                              WindowListener
{
  // create a java.sql.Date
  java.sql.Date jsqlDate = new java.sql.Date( 
     System.currentTimeMillis() );

  DateFormat dfLocal = DateFormat.getDateInstance( 
     DateFormat.SHORT );
  DateFormat dfGermany = DateFormat.getDateInstance( 
     DateFormat.SHORT, Locale.GERMANY );

  JButton    jb = new JButton( "Go" );
  JLabel     jlI = new JLabel("Input a Date:"),
             jlD = new JLabel("Display German:"),
             jlP = new JLabel("Parsed:");

  JPanel     jp = new JPanel();

  JTextField jtI = new JTextField( 10 ),
             jtD = new JTextField( 10 ),
             jtP = new JTextField( 10 );


  public JDFDP()
  {
    super( "JDFDP" );
    addWindowListener( this );

    jb.addActionListener( this );

    jp.add(jlI);
    jp.add(jtI);
    jp.add(jb);
    jp.add(jlD);
    jp.add(jtD);
    jp.add(jlP);
    jp.add(jtP);

    getContentPane().add( jp, BorderLayout.CENTER );
    pack();

    // set text by sending dummy event
    jtI.setText( dfLocal.format( jsqlDate ) );
    actionPerformed( 
       new ActionEvent( this, 12, "12" ) );

    show();

  }  // end constructor


  // ActionListener Implementation
  public void actionPerformed(ActionEvent e)
  {
    jtD.setText( "" );
    jtP.setText( "" );
    try
    {
      java.util.Date d = dfLocal.parse( 
         jtI.getText() );
      jtI.setText( dfLocal.format( d ) );
      jtD.setText( dfGermany.format( d ) );
      d = dfGermany.parse( jtD.getText() );
      // get new java.sql.Date
      jsqlDate = new java.sql.Date( d.getTime() );
      
      jtP.setText( jsqlDate.toString() );
    }
    catch( ParseException pe ) { jtI.setText( "" ); }

  }  // End actionPerformed


// Window Listener Implementation
  public void windowOpened(WindowEvent e) {}
  public void windowClosing(WindowEvent e)
  {
    dispose();
    System.exit(0);
  }
  public void windowClosed(WindowEvent e) {}
  public void windowIconified(WindowEvent e) {}
  public void windowDeiconified(WindowEvent e) {}
  public void windowActivated(WindowEvent e) {}
  public void windowDeactivated(WindowEvent e) {}
// End Window Listener Implementation


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

}  // end class JDFDP