Cant get image to load in JApplet - java.security.AccessControlException

Question

hi,
I need to make a JApplet that loads and displays images. Before I worry about media tracker or anything else I need to get the image to load.
My code is:
package Applet;
import java.awt.*; 
import javax.swing.*;
import java.applet.*;
* @author Nick
public class TestJApplet extends JApplet {
    /** Creates a new instance of TestJApplet */
    public TestJApplet() {
    public void init()
    public void paint(Graphics g)
        Image image;
        image = getImage(this.getDocumentBase(),"a.gif");
        g.drawRect(30,30,30,30);
}where a.gif is located in the same folder as the .java file.
I get the following message:
Exception in thread "AWT-EventQueue-1" java.security.AccessControlException: access denied (java.io.FilePermission \C:\Documents and Settings\Nick\Math\build\a.gif read)
        at java.security.AccessControlContext.checkPermission(AccessControlContext.java:264)
        at java.security.AccessController.checkPermission(AccessController.java:427)
        at java.lang.SecurityManager.checkPermission(SecurityManager.java:532)
        at java.lang.SecurityManager.checkRead(SecurityManager.java:871)
        at sun.awt.image.URLImageSource.<init>(URLImageSource.java:37)
        at sun.applet.AppletImageRef.reconstitute(AppletImageRef.java:33)
        at sun.misc.Ref.get(Ref.java:47)
        at sun.applet.AppletViewer.getCachedImage(AppletViewer.java:377)
        at sun.applet.AppletViewer.getImage(AppletViewer.java:372)
        at java.applet.Applet.getImage(Applet.java:236)
        at java.applet.Applet.getImage(Applet.java:258)
        at Applet.TestJApplet.paint(TestJApplet.java:27)
        at sun.awt.RepaintArea.paintComponent(RepaintArea.java:248)
        at sun.awt.RepaintArea.paint(RepaintArea.java:224)
        at sun.awt.windows.WComponentPeer.handleEvent(WComponentPeer.java:254)
        at java.awt.Component.dispatchEventImpl(Component.java:4031)
        at java.awt.Container.dispatchEventImpl(Container.java:2024)
        at java.awt.Component.dispatchEvent(Component.java:3803)
        at java.awt.EventQueue.dispatchEvent(EventQueue.java:463)
        at java.awt.EventDispatchThread.pumpOneEventForHierarchy(EventDispatchThread.java:242)
        at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:163)
        at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:157)
        at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:149)
        at java.awt.EventDispatchThread.run(EventDispatchThread.java:110)
Exception in thread "AWT-EventQueue-1" java.security.AccessControlException: access denied (java.io.FilePermission \C:\Documents and Settings\Nick\Math\build\a.gif read)
        at java.security.AccessControlContext.checkPermission(AccessControlContext.java:264)
        at java.security.AccessController.checkPermission(AccessController.java:427)
        at java.lang.SecurityManager.checkPermission(SecurityManager.java:532)
        at java.lang.SecurityManager.checkRead(SecurityManager.java:871)
        at sun.awt.image.URLImageSource.<init>(URLImageSource.java:37)
        at sun.applet.AppletImageRef.reconstitute(AppletImageRef.java:33)
        at sun.misc.Ref.get(Ref.java:47)
        at sun.applet.AppletViewer.getCachedImage(AppletViewer.java:377)
        at sun.applet.AppletViewer.getImage(AppletViewer.java:372)
        at java.applet.Applet.getImage(Applet.java:236)
        at java.applet.Applet.getImage(Applet.java:258)
        at Applet.TestJApplet.paint(TestJApplet.java:27)
        at sun.awt.RepaintArea.paintComponent(RepaintArea.java:248)
        at sun.awt.RepaintArea.paint(RepaintArea.java:224)
        at sun.awt.windows.WComponentPeer.handleEvent(WComponentPeer.java:254)
        at java.awt.Component.dispatchEventImpl(Component.java:4031)
        at java.awt.Container.dispatchEventImpl(Container.java:2024)
        at java.awt.Component.dispatchEvent(Component.java:3803)
        at java.awt.EventQueue.dispatchEvent(EventQueue.java:463)
        at java.awt.EventDispatchThread.pumpOneEventForHierarchy(EventDispatchThread.java:242)
        at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:163)
        at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:157)
        at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:149)
        at java.awt.EventDispatchThread.run(EventDispatchThread.java:110)Could someone help me get an image to load in an Applet/JApplet.
Cheers :)

Answer 1

From looking at your code there are two problems... the first is that you have a security exception being thrown because you are attempting to load a file locally with insufficient privileges to do so. This is because Applets have additional security levied on them so they don't say, in this circumstance steal a file off the loaded machine and send it back to the server that delivered them.
If you want to get your applet to load a local file (I don't think that is what you're asking here) then you have to digitally sign your applet and allow the user to decide if they want to be allow it to load a local file.
Nutshell is that you need to understand that the URL returned from getDocumentBase() in an applet is going to be from the Jar file you send the applet with or the URL you served the applet from. This is a bit of debugging code to show you what you are looking at and hopefully explain anything ambiguous I may have stated.
package testapplication;
import java.awt.EventQueue;
import java.awt.event.MouseEvent;
import java.awt.event.MouseListener;
* Description : <p></p>
* @author John Michael Resler<br/>
* Class : DocBaseApplet<br/>
* Creation Time : 8:31 AM<br/>
* Creation Date : June 18, 2006<br/>
* Compiler : Sun Java Community Edition (version 1.5.0_06)<br/>
public class DocBaseApplet extends javax.swing.JApplet implements MouseListener {
     * Initializes the applet DocBaseApplet
    public void init() {
        try {
            EventQueue.invokeAndWait(new Runnable() {
                public void run() {
                    initComponents();
        } catch (Exception ex) {
            ex.printStackTrace();
    private void initComponents() {
        documentBaseLabel = new javax.swing.JLabel();
        documentBaseLabel.addMouseListener(new java.awt.event.MouseAdapter() {
            public void mouseClicked(java.awt.event.MouseEvent evt) {
                documentBaseLabelMouseClicked(evt);
        org.jdesktop.layout.GroupLayout layout = new org.jdesktop.layout.GroupLayout(getContentPane());
        getContentPane().setLayout(layout);
        layout.setHorizontalGroup(
            layout.createParallelGroup(org.jdesktop.layout.GroupLayout.LEADING)
            .add(layout.createSequentialGroup()
                .addContainerGap()
                .add(documentBaseLabel, org.jdesktop.layout.GroupLayout.DEFAULT_SIZE, 376, Short.MAX_VALUE)
                .addContainerGap())
        layout.setVerticalGroup(
            layout.createParallelGroup(org.jdesktop.layout.GroupLayout.LEADING)
            .add(layout.createSequentialGroup()
                .addContainerGap()
                .add(documentBaseLabel, org.jdesktop.layout.GroupLayout.DEFAULT_SIZE, 274, Short.MAX_VALUE)
                .addContainerGap())
    private void documentBaseLabelMouseClicked(java.awt.event.MouseEvent evt) {                                              
        // TODO add your handling code here:
        this.documentBaseLabel.setText(this.getDocumentBase().toString());
    public void mouseClicked(MouseEvent e) {
    public void mousePressed(MouseEvent e) {
    public void mouseReleased(MouseEvent e) {
    public void mouseEntered(MouseEvent e) {
    public void mouseExited(MouseEvent e) {
    private javax.swing.JLabel documentBaseLabel;
}