Why an java.lang.IllegalAccessError?

Thanks for the reply corlettk.

Here is my Dao_Stairs class. As you can see I've declared the static integers as final like you suggested.

package blackdragon53.dao;

import java.io.*;

public class Dao_Stairs implements Serializable

{

public static final int LEVEL = 2;

public static final int SOLID = 1;

public static final int NORMAL = 0;

public static final int LEVELS = 30;

int[] type;

public Dao_Stairs()

{

type = new int[LEVELS];

refreshTypes();

}

public int getType(int level)

{

return type[level];

}

public void setType(int level, int newType)

{

type[level] = newType;

}

public void refreshTypes()

{

for(int i=0;i<LEVELS;i++)

{

type[i] = 0;

}

}

}

And here are the parts of Dao_ToN that are relevant.

import javax.swing.*;

import java.io.*;

import java.util.*;

import java.awt.*;

import java.awt.event.*;

import javax.swing.event.*;

import java.awt.image.BufferedImage;

import javax.imageio.ImageIO;

import blackdragon53.dao.*;

public class Dao_ToN

{

// Flags

public static final int BOARD = 0;

public static final int TITLE = 1;

public static final int MENU = 2;

public static final int MAP = 3;

public static final int SCENE = 4;

int solidFlag;

int stage = 0;

String errorMessage = "Unknown Error";

// Objects

Dao_Library library;

Dao_Board board;

Vector boardVector;

Vector boardCoordFlag;

JList boardList;

Component focusComponent;

// Frames

JFrame frame;

JDesktopPane contentPane;

JInternalFrame errorFrame;

JDesktopPane errorContentPane;

// Constructor

public Dao_ToN()

{

solidFlag = Dao_Stairs.SOLID;

JFrame.setDefaultLookAndFeelDecorated(true);

frame = new JFrame("Tears of Nighon");

frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

contentPane = new JDesktopPane();

contentPane.setBackground(Color.black);

contentPane.setOpaque(true);

contentPane.setDragMode(JDesktopPane.LIVE_DRAG_MODE);

frame.setContentPane(contentPane);

board = new Dao_Board();

boardCoordFlag = new Vector();

boardVector = new Vector();

boardList = new JList(boardVector);

library = new Dao_Library();

}

...

// Main

public static void main(String[] args)

{

Dao_ToN ton = new Dao_ToN();

ton.loadBoard("DaoTest1.dbd");

ton.renderMain();

}

...

The program compiles but during execution, throws an exception at the beginning of the constructor.

The weird part is that when I use 'blackdragon53.dao.Dao_Stairs' instead of 'Dao_Stairs', it works fine. But I'd prefer to have access to my static variables nonetheless.

Could it be the way the package is packaged? Since there is something wrong with this computer's ClassPath variable, I have just put my package in directory of this file + '/blackdragon53/dao/'.

Thanks for taking the time to help.>

Maykin53a at 2007-7-9 22:09:12 >

A good idea, thanks for the suggestion.

There was, however, no Dao_Stairs class in the directory. Since Dao_Stairs is part of a package that I created with a different project earlier, it has already been compiled within the package, so when I compile the new project, Dao_Stairs doesn't need to be compiled.

I'm also having problems with putting packages in different directories and setting the classpath variable, so I think I may have to re-install Java - it could be a problem associated with the package.

Thankyou both for your help.

Maykin53a at 2007-7-9 22:09:13 >

Here is a list of what does and doesn't work;

import blackdragon53.dao*; // works

Dao_Stairs stairs = new Dao_Stairs(); // works

int solid = Dao_Stairs.SOLID; // throws illegal access error at runtime

int solid = blackdragon53.dao.Dao_Stairs.SOLID; // works

int type = Dao_Stairs.getType(1); // works

Maykin53a at 2007-7-9 22:09:13 >

> In this same directory, I have the following

> sub-directory "/blackdragon53/dao/" that contains the

> class files from the package 'blackdragon53.dao'.

Okay, then "this same directory"--the one that contains blackdragon53--should be on your classpath.

> The classpath variable is currently "C:\Program

> Files\QuickTime\QTSystem\QTJava.zip;C:\Program

> Files\Java\jre1.5.0_11\lib\ext\";

Get the Java ext directory off of there. You don't need it. I don't see anything there that will let you find Dao_Stairs or any of your other classes. How are you running this?

> Since I can already declare and initialise Dao_Stairs

> objects and make use of its public methods, shouldn't

> I be able to access Static attributes?

Yes. So something fishy is going on.

jverda at 2007-7-21 17:37:54 >

Try running from the command line like so:

java -cp <whatever> -verbose:class WhatverYourClassIs

This will show you all the classes it loads and from where. You might have to add > someFile

if the output scrolls past your screen.

Paste the exact command here, and what it says about where it loaded Dao_Stairs from.

jverda at 2007-7-21 17:37:54 >

>Get the Java ext directory off of there. You don't need it. I don't see >anything there that will let you find Dao_Stairs or any of your other >classes. How are you running this?

It is on there because previously I tried to run my program with the blackdragon53.dao package inside that directory instead, but it wouldn't even compile, saying the package doesn't exist.

I added the directory of the package (which is the directory of Dao_ToN.class) to the classpath just now but there is no difference in execution.

At first I was using JCreator, now I'm trying to execute it from the command line - both return the same outcome.

Maykin53a at 2007-7-21 17:37:54 >

Ok, I ran the -cp command as follows;

java -cp . -verbose:class Dao_ToN

and like you said the output was too much. I'm not exactly sure what you mean by > File.

Anyway I did this command;

javac blackdragon53\dao\Dao_Stairs.java Dao_ToN.java

And received a 'javac is not recognised as an internal or external command, operation program or batch file' error.

Btw, I've been using the IDE JCreator to compile (but I have also been executing from the command line to make sure it is not because of JCreator).

Maykin53a at 2007-7-21 17:37:54 >

> Hm.. I do recall installing the full JDK.

>

> My PATH variable is;

>

> C:\Program Files\Java\jre1.5.0_11\bin

>

> Is this correct?

That's just the JRE, which you need for running java programs, but which is not sufficient for compiling them. It would be something like C:\jdk1.5.0_06\bin or something. Look for a directory with jdk in the name, and there should be a bin underneath that that has javac.exe in it. That bin directory needs to be on your path. It will also contain java.exe, so you can get rid of the JRE bin.

jverda at 2007-7-21 17:37:59 >

Ok, I added the JKD bin directory to my Path variable. Now I can use the 'javac' command - thanks for the help.

I ran;

javac blackdragon53.dao.Dao_Stairs.java Dao_ToN.java

and received a 'cannot read file Dao_Stairs.java' error.

I ran;

javac Dao_ToN.java

and i received errors for declaring all of my objects, including those that are in the same directory as Dao_ToN.

Maykin53a at 2007-7-21 17:37:59 >

> Ok, I added the JKD bin directory to my Path

> variable. Now I can use the 'javac' command - thanks

> for the help.

>

> I ran;

>

> javac blackdragon53.dao.Dao_Stairs.java

> Dao_ToN.java

javac blackdragon53\dao\Dao_Stairs.java

> Dao_ToN.java

Backslashes, not dots, to separate directories. You're just telling javac which files to compile--these aren't java package and class names you're passing here.

> I ran;

>

> javac Dao_ToN.java

>

> and i received errors for declaring all of my

> objects, including those that are in the same

> directory as Dao_ToN.

Not sure what you're saying here. Can you paste in the exact error messages?

jverda at 2007-7-21 17:37:59 >

By the way, if it makes you feel any better, this stuff isn't nearly as complicated as it's seeming now. It can be confusing at first, and it's a major pain to try to explain--especially on a forum when I can't see firsthand what's going on and can't easily tell or show you what to do--but once you get the main points down and get a little used to it, you'll wonder why you ever had trouble with it. :-)

jverda at 2007-7-21 17:37:59 >

>No. You can't have gotten that error in that case.

I'm sorry if I'm doing something wrong, but I repeated the command and made sure it was correct.

The command worked, since I got a lot of lines such as [loaded] .......

but they were all for 'java.util.<something>'.. When it came time to load Dao_Stairs, it came across that error.

Maykin53a at 2007-7-21 17:37:59 >

> >Not sure what you're saying here, but don't worry

> about it. As long as

> >you're not putting your classes into Java's

> directories.

>

> Dao_ToN imports java.util.* as well as other standard

> packages. It seems to load them from the directory I

> meantioned.

Ah, I see.

It gets them from rt.jar, which is in the lib directory, not ext. You DON'T need the stuff under the Java directory on your classpath though. It will be found relative to the VM or JAVA_HOME.

jverda at 2007-7-21 17:37:59 >

There must be a reason why I can compile and execute using JCreator but am unable to compile using the command line (due to errors).

Perhaps a classpath issue? But then, my classpath is set as it should be (i'm almost certain) and then why can i execute from JCreator but still get an illegal access error?

It's all so strange. This computer is pretty old and hasn't been reformatted in a long time - it is my friend's computer that I am using until I can replace my broken one. In a few days I hope to try on my new computer to see if it works.

Maykin53a at 2007-7-21 17:38:03 >

jverd, thankyou for of your help. Fortunately, I came up with an idea as to what the problem could be. Underscores in my class names (Dao_...).

I've never seen or heard any meantion of underscores being a problem, and though I posted my classes and their names on these forums noone has told me underscores can be troublesome.

The thing is, when I created my first project 'Dao_TileEdtor' (for which all its files became the blackdragon53.dao package), it worked perfectly.

However, I started running into problem when I wanted to use this package in my new project 'Dao_ToN'. I could access the classes and their methods, but when I tried to access their Static Attributes, I came across this problem.

So to make sure it wasn't because of 'Dao_Stairs', I created a 'Test' class and i COULD access its static members. How strange.

Then I decided to go back and remove Test from the package - when I recompiled Dao_TileEditor project, something strange happened - it created 3 files DaoTileEditor, DaoBoard, and DaoTile - 3 BLANK files representing those that were already in the project/package but without underscores. It tried to execute DaoTileEditor.

This could have been a bug in the IDE, so I renamed ALL of my classes so that none of them had underscores (and replaced references).

It worked.

Everything including DaoToN worked.

So Either;

- Java, my IDE, or this OS currently has problems with underscores in package class names when accessing static members.

or

- There was a Dao_Stairs class somewhere, hidden, possibly in a temp file or an IDE reference file, and renaming the classes cleared the reference to Dao_Stairs.

I'm more included to think the latter.

Maykin53a at 2007-7-21 17:38:03 >