java.lang.ArrayIndexOutOfBoundsException exception in thread

[Dindy Oreeda]

Hi, Guys! I'm making a GUI version of our final project about Memory allocation and program scheduling when I met this error.
After looking up in the internet for solutions and double checking my codes. I can't still find what's wrong with my program.

The error is
Exception in thread "AWT-EventQueue-0" java.lang.ArrayIndexOutOfBoundsException: 0
at osProject.DesignInterface.addJobSpecs(DesignInterface.java:153)
at osProject.DesignInterface.actionPerformed(DesignInterface.java:200)
at javax.swing.AbstractButton.fireActionPerformed(Unknown Source)
at javax.swing.AbstractButton$Handler.actionPerformed(Unknown Source)
at javax.swing.DefaultButtonModel.fireActionPerformed(Unknown Source)
at javax.swing.DefaultButtonModel.setPressed(Unknown Source)
at javax.swing.plaf.basic.BasicButtonListener.mouseReleased(Unknown Source)
at java.awt.Component.processMouseEvent(Unknown Source)
at javax.swing.JComponent.processMouseEvent(Unknown Source)
at java.awt.Component.processEvent(Unknown Source)
at java.awt.Container.processEvent(Unknown Source)
at java.awt.Component.dispatchEventImpl(Unknown Source)
at java.awt.Container.dispatchEventImpl(Unknown Source)
at java.awt.Component.dispatchEvent(Unknown Source)
at java.awt.LightweightDispatcher.retargetMouseEvent(Unknown Source)
at java.awt.LightweightDispatcher.processMouseEvent(Unknown Source)
at java.awt.LightweightDispatcher.dispatchEvent(Unknown Source)
at java.awt.Container.dispatchEventImpl(Unknown Source)
at java.awt.Window.dispatchEventImpl(Unknown Source)
at java.awt.Component.dispatchEvent(Unknown Source)
at java.awt.EventQueue.dispatchEventImpl(Unknown Source)
at java.awt.EventQueue.access$000(Unknown Source)
at java.awt.EventQueue$1.run(Unknown Source)
at java.awt.EventQueue$1.run(Unknown Source)
at java.security.AccessController.doPrivileged(Native Method)
at java.security.AccessControlContext$1.doIntersectionPrivilege(Unknown Source)
at java.security.AccessControlContext$1.doIntersectionPrivilege(Unknown Source)
at java.awt.EventQueue$2.run(Unknown Source)
at java.awt.EventQueue$2.run(Unknown Source)
at java.security.AccessController.doPrivileged(Native Method)
at java.security.AccessControlContext$1.doIntersectionPrivilege(Unknown Source)
at java.awt.EventQueue.dispatchEvent(Unknown Source)
at java.awt.EventDispatchThread.pumpOneEventForFilters(Unknown Source)
at java.awt.EventDispatchThread.pumpEventsForFilter(Unknown Source)
at java.awt.EventDispatchThread.pumpEventsForHierarchy(Unknown Source)
at java.awt.EventDispatchThread.pumpEvents(Unknown Source)
at java.awt.EventDispatchThread.pumpEvents(Unknown Source)
at java.awt.EventDispatchThread.run(Unknown Source)

My codes are :

package osProject;

import java.awt.BorderLayout;
import java.awt.*;
import javax.swing.*;
import java.awt.event.*;
import javax.swing.border.*;
import java.util.*;
import java.io.*;



 class DesignInterface implements ActionListener
{
		//settings
		 ProcessFlow PF = new ProcessFlow();
		
		 String []jobs = { "2", "3", "4", "5", "6"};
				
	 	//frames
		JFrame MIframe = new JFrame("Memory Initialization");
		JFrame JSframe = new JFrame("Job Specifications");
		JFrame PSframe = new JFrame("Process Specifications");
		
		
		//panels
		JPanel pnlLeft;
		JPanel pnlCenter;
		JPanel pnlRight; 
		JPanel pnlTotal; 
		//Buttons 
		JButton cmdEnter= new JButton("Enter");
				
		//outputs
		JLabel lblmemspace = new JLabel("Enter total Memory Space(in KB): ");
		JLabel lblnumjobs = new JLabel("Number of Jobs to be loaded in the Memory: ");
		JLabel lblj = new JLabel("JOBS");
		JLabel lbls = new JLabel("SIZE(KB)");
		JLabel lbla = new JLabel("ARRIVAL TIME(msec)");
		JLabel []lbljobs =  new JLabel[PF.getNumjobs()];
		JTextField []txtsize =  new JTextField[PF.getNumjobs()];
		JTextField []txtArrTime=  new JTextField[PF.getNumjobs()];
		
		//inputs
		JTextField txtmemspace = new JTextField(8);
		JComboBox cbonumjobs= new JComboBox(jobs);
		
	//constructor
	DesignInterface()
	{
		addMemInitialize();	
		
	}
		
	public void addMemInitialize() 
	{
		MIframe.setSize(400, 175);
		MIframe.setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);
		MIframe.setLocationRelativeTo(null);
		MIframe.setResizable(false);
		
		pnlTotal = new JPanel();
		pnlTotal.setLayout(null);
		
		//label panels
		pnlLeft = new JPanel();
		pnlLeft.setLayout(null);
		pnlLeft.setLocation(10, 10);
		pnlLeft.setSize(260, 80);
		pnlTotal.add(pnlLeft);
		
		//memspace labels
		lblmemspace.setLocation(0, 0);
		lblmemspace.setSize(260, 40);
		lblmemspace.setHorizontalAlignment(4);
		pnlLeft.add(lblmemspace);
		
		//numjobs label
		lblnumjobs.setLocation(0, 40);
		lblnumjobs.setSize(260,40);
		lblnumjobs.setHorizontalAlignment(4);
		pnlLeft.add(lblnumjobs);
		
		//textfields panel
		pnlRight = new JPanel();
	    pnlRight.setLayout(null);
	    pnlRight.setLocation(270,15);
	    pnlRight.setSize(100,70);
	    pnlTotal.add(pnlRight);

	    //mempspace textfield
	    txtmemspace.setLocation(0, 0);
	    txtmemspace.setSize(100,30);
		pnlRight.add(txtmemspace);
		
		 // cbonumjobs textfield
	    cbonumjobs.setLocation(0, 40);
	    cbonumjobs.setSize(100,30);
		pnlRight.add(cbonumjobs);
		
		cmdEnter.setSize(80, 30);
		cmdEnter.setLocation(150, 100);
		cmdEnter.addActionListener(this);
	    pnlTotal.add(cmdEnter);
	    pnlTotal.setOpaque(true);
		
		MIframe.add(pnlTotal);
		
		MIframe.setVisible(true);
		
	}//meminitialize
	
	public void addJobSpecs()
	{
		int t = PF.getNumjobs();
		int l = 0; int n = 1;
		
		JSframe.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
		JSframe.setLocationRelativeTo(null);
		JSframe.setResizable(false);
		
		pnlLeft.removeAll();
		pnlRight.removeAll();
		pnlTotal.removeAll();
				
		//labels
		lblj.setSize(100,40);
		lblj.setLocation(10,10);
		lblj.setHorizontalAlignment(4);
		pnlTotal.add(lblj);
		
		lbls.setSize(100,40);
		lbls.setLocation(135,10);
		lbls.setHorizontalAlignment(4);
		pnlTotal.add(lbls);
				
		lbla.setSize(100,40);
		lbla.setLocation(160,10);
		lbla.setHorizontalAlignment(4);
		pnlTotal.add(lbla);
		//panels
		pnlCenter = new JPanel();
		pnlCenter.setLayout(null);
		pnlCenter.setSize(100, 40 * t);
		pnlCenter.setLocation(135,50);
		pnlLeft.setSize(100, 40 * t);
		pnlLeft.setLocation(10,45);
		pnlRight.setSize(100, 40 * t);
		pnlRight.setLocation(160,50);
				
		for(int i = 0 ; i < t ; i++, n++)
		{
			lbljobs[i] = new JLabel(n + "");
			lbljobs[i].setSize(100, 40);
			lbljobs[i].setHorizontalAlignment(4);
			lbljobs[i].setLocation(0, l);
			
			txtsize[i] = new JTextField();
			txtsize[i].setSize(100, 30);
			txtsize[i].setLocation(0, l);
			
			txtArrTime[i] = new JTextField();
			txtArrTime[i].setSize(100,30);
			txtArrTime[i].setLocation(0, l);
			
			pnlLeft.add(lbljobs[i]);
			pnlCenter.add(txtsize[i]);
			pnlRight.add(txtArrTime[i]);
			l = l + 40;
		}//loop
						
		pnlTotal.add(pnlLeft);
		pnlTotal.add(pnlCenter);
		pnlTotal.add(pnlRight);
		pnlLeft.revalidate();
		pnlRight.revalidate();
		pnlTotal.revalidate();
		JSframe.add(pnlTotal);
		pnlLeft.repaint();
		pnlRight.repaint();
		pnlTotal.repaint();
		JSframe.setSize(375,(40 * t + 30));
		JSframe.setVisible(true);
	}
	
	public void actionPerformed(ActionEvent e)
	{
		
		Double mspace = 0.0; 
		if(cmdEnter == e.getSource()){
			
			try{
				 mspace = Double.parseDouble(txtmemspace.getText().trim()); 
			}catch(NumberFormatException ex){
				JOptionPane.showMessageDialog(null, " Memory Space must be numerical ", "Number Format Error", JOptionPane.ERROR_MESSAGE);
			}//catch
			PF.setMemspace(mspace);
			PF.setNumjobs(Integer.parseInt(jobs[cbonumjobs.getSelectedIndex()]));
			MIframe.setVisible(false);
			addJobSpecs();
		}
			
		
	}//event
	
	 public static void main(String[] args)
	 {
		 DesignInterface di = new DesignInterface();
	      
	 }//main

}//end class

Feel free to give me some tips and advices. I really appreciate them. Please help me and thanks guys!

[Matthew Brown]

I don't know what the exact problem is, but errors like that are usually because you're making changes to Swing components outside the Swing thread. I'm going to move this to the Swing forum because I think you're more likely to get a useful response there.

[Darryl Burke]

http://docs.oracle.com/javase/tutorial/uiswing/concurrency/initial.html

[Prabakar Kalivaradan]

The exception says index 0 is not accessible. That can occur in the following scenario.

String[] names = new String[0];//allocated space (0 size) for names array (no element can be put in this array)

System.out.println(names[0]);// trying to access first element in names array; this will give the same exception you are encountering

Start looking from osProject.DesignInterface.addJobSpecs(DesignInterface.java:153) method...

[Dindy Oreeda]

Thanks Guys! I read about it and saw my mistake. Thank you for helping me and guiding me