Simple Java OpenGL Textures Manager

I'm trying to make a simple textures manager for a 2D tile-based project.

What I have is a class that has a hashmap of strings (texture name) and textures. If the name doesn't exist in the hashmap, it uses TextureIO.newTexture(..) to create it and store it into the hashmap.

This is the error I get when I try to load a texture:

Exception in thread "Timer-0" javax.media.opengl.GLException: java.lang.IllegalArgumentException: Illegally formatted version identifier: "null"

    at javax.media.opengl.Threading.invokeOnOpenGLThread(Threading.java:271)

    at javax.media.opengl.GLCanvas.maybeDoSingleThreadedWorkaround(GLCanvas.java:410)

    at javax.media.opengl.GLCanvas.display(GLCanvas.java:244)

    at com.sun.opengl.util.Animator.display(Animator.java:144)

    at com.sun.opengl.util.FPSAnimator$1.run(FPSAnimator.java:95)

    at java.util.TimerThread.mainLoop(Unknown Source)

    at java.util.TimerThread.run(Unknown Source)

Caused by: java.lang.IllegalArgumentException: Illegally formatted version identifier: "null"

    at com.sun.opengl.impl.FunctionAvailabilityCache$Version.<init>(FunctionAvailabilityCache.java:354)

    at com.sun.opengl.impl.FunctionAvailabilityCache.initAvailableExtensions(FunctionAvailabilityCache.java:133)

    at com.sun.opengl.impl.FunctionAvailabilityCache.isExtensionAvailable(FunctionAvailabilityCache.java:104)

    at com.sun.opengl.impl.GLContextImpl.isExtensionAvailable(GLContextImpl.java:351)

    at com.sun.opengl.impl.GLImpl.isExtensionAvailable(GLImpl.java:30493)

    at com.sun.opengl.util.texture.Texture.updateImage(Texture.java:416)

    at com.sun.opengl.util.texture.Texture.updateImage(Texture.java:381)

    at com.sun.opengl.util.texture.Texture.<init>(Texture.java:182)

    at com.sun.opengl.util.texture.TextureIO.newTexture(TextureIO.java:445)

    at com.sun.opengl.util.texture.TextureIO.newTexture(TextureIO.java:465)

    at dqs.manager.TextureManager.loadTexture(TextureManager.java:31)

    at dqs.world.World.draw(World.java:59)

    at dqs.scene.GameScene.display(GameScene.java:58)

    at com.sun.opengl.impl.GLDrawableHelper.display(GLDrawableHelper.java:78)

    at javax.media.opengl.GLCanvas$DisplayAction.run(GLCanvas.java:435)

    at com.sun.opengl.impl.GLDrawableHelper.invokeGL(GLDrawableHelper.java:194)

    at javax.media.opengl.GLCanvas$DisplayOnEventDispatchThreadAction.run(GLCanvas.java:452)

    at java.awt.event.InvocationEvent.dispatch(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.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)

Caused by: java.lang.NullPointerException

    at com.sun.opengl.impl.FunctionAvailabilityCache$Version.<init>(FunctionAvailabilityCache.java:309)

    ... 30 more

Exception in thread "AWT-EventQueue-0" java.lang.NullPointerException

    at com.sun.opengl.impl.mipmap.Mipmap.closestFit(Mipmap.java:252)

    at com.sun.opengl.impl.mipmap.Mipmap.gluBuild2DMipmaps(Mipmap.java:726)

    at javax.media.opengl.glu.GLU.gluBuild2DMipmapsJava(GLU.java:1525)

    at javax.media.opengl.glu.GLU.gluBuild2DMipmaps(GLU.java:1581)

    at com.sun.opengl.util.texture.Texture.updateImage(Texture.java:523)

    at com.sun.opengl.util.texture.Texture.updateImage(Texture.java:381)

    at com.sun.opengl.util.texture.Texture.<init>(Texture.java:182)

    at com.sun.opengl.util.texture.TextureIO.newTexture(TextureIO.java:445)

    at com.sun.opengl.util.texture.TextureIO.newTexture(TextureIO.java:465)

    at dqs.manager.TextureManager.loadTexture(TextureManager.java:31)

    at dqs.world.World.draw(World.java:59)

    at dqs.scene.GameScene.display(GameScene.java:58)

    at com.sun.opengl.impl.GLDrawableHelper.display(GLDrawableHelper.java:78)

    at javax.media.opengl.GLCanvas$DisplayAction.run(GLCanvas.java:435)

    at com.sun.opengl.impl.GLDrawableHelper.invokeGL(GLDrawableHelper.java:194)

    at javax.media.opengl.GLCanvas.maybeDoSingleThreadedWorkaround(GLCanvas.java:412)

    at javax.media.opengl.GLCanvas.display(GLCanvas.java:244)

    at javax.media.opengl.GLCanvas.paint(GLCanvas.java:277)

    at sun.awt.RepaintArea.paintComponent(Unknown Source)

    at sun.awt.RepaintArea.paint(Unknown Source)

    at sun.awt.windows.WComponentPeer.handleEvent(Unknown Source)

    at java.awt.Component.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)

The error occurs the moment I call loadTexture from within my TextureManager.

Here is the TextureManager code:

public class TextureManager {



    private static HashMap<String, Texture> textureMap;



    public TextureManager() {



        textureMap = new HashMap<String, Texture>();



    }



    public static void loadTexture(String name) {



        if(textureMap.containsKey(name)) return;



        try {



            textureMap.put(name, TextureIO.newTexture(new File("textures/" + name + ".png"), true));

        }

        catch (GLException e) {



            e.printStackTrace();

        }

        catch (IOException e) {



            e.printStackTrace();

        }

    }



    public static void bindTexture(String name) {



        textureMap.get(name).bind();

    }

}

A TextureManager object has already been created earlier in the code via:

new TextureManager();

This is the code that I called it using:

TextureManager.loadTexture("tree");

The path textures/tree.png exists too.

I did something similar to this in an older project, but instead of using a hashmap, I hard coded a variable in the TextureManager for every texture I used (not many). I suspect It's because the thread lacks a GL context because my old TextureManager passed GL in via the constructor, but never used it in the code. The draw function that called the loadTexture function also passed in a GL variable.