Error: NullPointerException

Question

HI All ,
Error : NullPointerException .
I have got this above error in the Reciever comm channel of JMS Adapter ,
Could anyone answer detailly .
Regards.
Syed Nayeem.

Answer 1

Umm, this is what my code looks like. I tried it, but it doesn't work.
import model.*;
import java.awt.*;
import java.awt.event.*;
import java.text.*;
import javax.swing.*;
public class ButtonPanel extends JPanel implements View
    private Prison prison;
    private LeftInputPanel leftInput = new LeftInputPanel(prison);
    private DaysPanel days;
    private MonthsPanel months;
    private YearsPanel years;
    private CrimePanel crime;
    private AllocateListener aListener = new AllocateListener();
    public ButtonPanel(Prison prison)
        this.prison = prison;
        setup();
        build();
    public void setup()
    public void build()
        JButton button = new JButton("Allocate Cell");
        Dimension size = new Dimension(240, 70);
        button.setPreferredSize(size);
        button.setMinimumSize(size);
        button.setMaximumSize(size);
        button.addActionListener(aListener);
        add(button);
        update();
    public void update()
        leftInput.update();
private class AllocateListener implements ActionListener
    public void actionPerformed(ActionEvent e)
        Criminal criminal = new Criminal(leftInput.name());
        Period period = new Period(days.days(), months.months(), years.years());  //nullPointerException here
        criminal.set(new Crime(crime.getCrime()));
        prison.add(criminal);
}Edited by: karen.tao on Oct 24, 2009 6:11 AM