Thread: Problem with Jbutton

Hello,

I am having problem with the program below. I can get the nextJButton to work but the previousJButton won't. previousJButton is supposed to make the page number go down, but it won't reflect on screen(in a label).

private class ButtonHandler implements ActionListener
{
      public void actionPerformed(ActionEvent e)
     {
 
            label10.setText("");
            Page++;
            Object src=e.getSource();
 
           System.out.printf("%d",Page);
           if(src==nextJButton) //this button works fine
           {
 
	        if (Page==1)
                {
 
                           label1.setText(formatter5.toString());
			   label2.setText(formatter6.toString());
                           label3.setText(formatter7.toString());					  
 
			   String labelText = ( "Page number: " + (Page+1) );
			   label10.setText( labelText );
	        }
 
               else
               {
 
                      label1.setText(formatter5.toString());
                      label2.setText(formatter3.toString());
                      label3.setText(formatter7.toString());
 
		      String labelText = ( "Page number: " + (Page+1) );
		      label10.setText( labelText );
 
		}
 
            }
 
		if(src==previousJButton)//here is the problem button
                {
 
                     label10.setText("");
		     Page--;
		     String labelText = ( "Page number: " + (Page+1) );
		     label10.setText( labelText );
 
		}
 
	}
    }

Here is the whole program so you can run it

import java.util.Vector;
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import java.io.*;
import java.awt.BorderLayout;
import java.awt.FlowLayout;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import java.awt.GridLayout;
import javax.swing.JTextField;
import javax.swing.JOptionPane;
import java.util.Formatter;
import java.util.Random;
 
 
public class RunnableDataEntry extends JFrame implements FocusListener,KeyListener,ActionListener
{
	private JButton nextJButton;
	private JButton previousJButton;
 
	private JLabel label1;
	private JLabel label2;
	private JLabel label3;
	private JLabel label10;
 
	private JPanel Panel1;
	private JPanel Panel2;
	private JPanel Panel3;
	private JPanel Panel4;
	private JPanel Panel5;
 
	private BorderLayout layout;
	private GridLayout gridLayout1;
	private FlowLayout flowLayout1;
 
	private int Page;
 
 
 
    private int array[]=new int[24];
    //private int array[]=new int[2];
 
    Formatter formatter=new Formatter();
    Formatter formatter2=new Formatter();
    Formatter formatter3=new Formatter();
    Formatter formatter4=new Formatter();
    Formatter formatter5=new Formatter();
    Formatter formatter6=new Formatter();
    Formatter formatter7=new Formatter();
    Formatter formatter8=new Formatter();
 
    public RunnableDataEntry()
	{
		super("Runnable Data Entry");
 
		layout = new BorderLayout(5,10);
                nextJButton=new JButton("Next Page");
                previousJButton=new JButton("Previous Page");
		flowLayout1= new FlowLayout();
		setLayout(layout);
		Panel1 = new JPanel();
		Panel2=new JPanel();
		Panel3=new JPanel();
		Random randomNumber=new Random();
 
		for(int counter=0;counter<array.length;counter++)
		{
 
                 array[counter]=randomNumber.nextInt(10);
 
		}
 
formatter.format("%d%d%d%d",array[0],array[1],array[2],array[3]);
		formatter2.format("%d%d%d%d",array[4],array[5],array[6],array[7]);
		formatter3.format("%d%d%d%d",array[8],array[9],array[10],array[11]);
		formatter5.format("%d%d%d%d",array[12],array[13],array[14],array[15]);
		formatter6.format("%d%d%d%d",array[16],array[17],array[18],array[19]);
		formatter7.format("%d%d%d%d",array[20],array[21],array[22],array[23]);
 
 
 
		label1=new JLabel(formatter.toString());
		label2=new JLabel(formatter2.toString());
		label3=new JLabel(formatter3.toString());
		label10=new JLabel(formatter8.toString());
 
		add(Panel3,BorderLayout.WEST);
			Panel3.add(label10);
 
		add(Panel1,BorderLayout.NORTH);
			Panel1.setLayout(flowLayout1);
			Panel1.add(label1);
			Panel1.add(label2);
			Panel1.add(label3);
 
		add(Panel2,BorderLayout.SOUTH);
			Panel2.add(nextJButton);
			Panel2.add(previousJButton);
 
		ButtonHandler handler=new ButtonHandler();
		nextJButton.addActionListener(handler);
		previousJButton.addActionListener(handler);
 
		label10.setText("");
		String labelText = ( "Page number: " + (Page+1) );
		label10.setText( labelText );
 
	}
 
		private class ButtonHandler implements ActionListener
		{
 
 
 
        	public void actionPerformed(ActionEvent e)
        	{
 
                label10.setText("");
                Page++;
                Object src=e.getSource();
 
                System.out.printf("%d",Page);
                 if(src==nextJButton) //this button works fine
                {
 
	              if (Page==1)
                      {
 
                           label1.setText(formatter5.toString());
			   label2.setText(formatter6.toString());
                           label3.setText(formatter7.toString());					  
 
			   String labelText = ( "Page number: " + (Page+1) );
			   label10.setText( labelText );
		           }
 
                   else
                   {
 
                      label1.setText(formatter5.toString());
                      label2.setText(formatter3.toString());
                      label3.setText(formatter7.toString());
 
		      String labelText = ( "Page number: " + (Page+1) );
		      label10.setText( labelText );
 
		       }
 
		}
 
		if(src==previousJButton)//here is the problem button
                {
 
                     label10.setText("");
		     Page--;
		     String labelText = ( "Page number: " + (Page+1) );
		     label10.setText( labelText );
 
		}
 
	}
    }
 
    public void focusGained(FocusEvent e)
    {
 
    }
 
 
    public void focusLost(FocusEvent e)
    {
 
    }
 
 
    public void keyTyped(KeyEvent e)
    {
 
    }
 
    public void keyPressed(KeyEvent e)
    {
 
    }
 
 
    public void keyReleased(KeyEvent e) {
 
    }
 
 
    public void actionPerformed(ActionEvent event)
    {
 
    }
 
}

I use this in a separate file to get the program to run
import javax.swing.JFrame;

public class RunnableDataEntryTest
{
	public static void main(String args[])
	{
		RunnableDataEntry runnabledataEntry = new RunnableDataEntry();
	      runnabledataEntry.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
		runnabledataEntry.setSize(500,500);
		runnabledataEntry.setVisible( true );
        }
}

Please describe what's not working. What is the previousJButton supposed to do? What is it doing instead, if anything?

The code you've posted is the kind of (forgive me) crap people get from graphical code builders who have not taken the time to rename the variables, add meaningful comments, etc. People who post code like this give the graphical code builders an even worse rep than they already have which is already well deserved. Please learn to use the graphical code builder to your advantage rather than to your doom and then post THAT code.

Sorry for how sloppy the code was, I have fixed it up some.