此applet工作正常，直到昨天，现在它给了我一些例外。这是堆栈跟踪：
java.security.AccessControlException: access denied ("java.lang.RuntimePermission" "getenv.localappdata")
Exception in thread "AWT-EventQueue-1" java.security.AccessControlException: access denied ("java.lang.RuntimePermission" "modifyThreadGroup")
at java.security.AccessControlContext.checkPermission(AccessControlContext.java:366)
at java.security.AccessController.checkPermission(AccessController.java:560)
at java.lang.SecurityManager.checkPermission(SecurityManager.java:549)
at sun.applet.AppletSecurity.checkAccess(AppletSecurity.java:252)
at java.lang.ThreadGroup.checkAccess(ThreadGroup.java:315)
at java.lang.Thread.init(Thread.java:376)
at java.lang.Thread.<init>(Thread.java:485)
at javax.swing.plaf.basic.BasicDirectoryModel$LoadFilesThread.<init>(BasicDirectoryModel.java:222)
at javax.swing.plaf.basic.BasicDirectoryModel.validateFileCache(BasicDirectoryModel.java:140)
at javax.swing.plaf.basic.BasicDirectoryModel.propertyChange(BasicDirectoryModel.java:69)
at java.beans.PropertyChangeSupport.fire(PropertyChangeSupport.java:335)
at java.beans.PropertyChangeSupport.firePropertyChange(PropertyChangeSupport.java:327)
at java.beans.PropertyChangeSupport.firePropertyChange(PropertyChangeSupport.java:263)
at java.awt.Component.firePropertyChange(Component.java:8382)
at javax.swing.JFileChooser.setCurrentDirectory(JFileChooser.java:581)
at javax.swing.JFileChooser.<init>(JFileChooser.java:344)
at javax.swing.JFileChooser.<init>(JFileChooser.java:296)
at gui1.jButton1ActionPerformed(gui1.java:148)
at gui1.access$000(gui1.java:21)
at gui1$1.actionPerformed(gui1.java:62)
at javax.swing.AbstractButton.fireActionPerformed(AbstractButton.java:2018)
at javax.swing.AbstractButton$Handler.actionPerformed(AbstractButton.java:2341)
at javax.swing.DefaultButtonModel.fireActionPerformed(DefaultButtonModel.java:402)
at javax.swing.DefaultButtonModel.setPressed(DefaultButtonModel.java:259)
at javax.swing.plaf.basic.BasicButtonListener.mouseReleased(BasicButtonListener.java:252)
at java.awt.Component.processMouseEvent(Component.java:6505)
at javax.swing.JComponent.processMouseEvent(JComponent.java:3321)
at java.awt.Component.processEvent(Component.java:6270)
at java.awt.Container.processEvent(Container.java:2229)
at java.awt.Component.dispatchEventImpl(Component.java:4861)
at java.awt.Container.dispatchEventImpl(Container.java:2287)
at java.awt.Component.dispatchEvent(Component.java:4687)
at java.awt.LightweightDispatcher.retargetMouseEvent(Container.java:4832)
at java.awt.LightweightDispatcher.processMouseEvent(Container.java:4492)
at java.awt.LightweightDispatcher.dispatchEvent(Container.java:4422)
at java.awt.Container.dispatchEventImpl(Container.java:2273)
at java.awt.Component.dispatchEvent(Component.java:4687)
at java.awt.EventQueue.dispatchEventImpl(EventQueue.java:729)
at java.awt.EventQueue.access$200(EventQueue.java:103)
at java.awt.EventQueue$3.run(EventQueue.java:688)
at java.awt.EventQueue$3.run(EventQueue.java:686)
at java.security.AccessController.doPrivileged(Native Method)
at java.security.ProtectionDomain$1.doIntersectionPrivilege(ProtectionDomain.java:76)
at java.security.ProtectionDomain$1.doIntersectionPrivilege(ProtectionDomain.java:87)
at java.awt.EventQueue$4.run(EventQueue.java:702)
at java.awt.EventQueue$4.run(EventQueue.java:700)
at java.security.AccessController.doPrivileged(Native Method)
at java.security.ProtectionDomain$1.doIntersectionPrivilege(ProtectionDomain.java:76)
at java.awt.EventQueue.dispatchEvent(EventQueue.java:699)
at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:242)
at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:161)
at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:150)
at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:146)
at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:138)
at java.awt.EventDispatchThread.run(EventDispatchThread.java:91)
BUILD SUCCESSFUL (total time: 34 seconds)
我还创建了一个策略文件，并将其放在user.home目录中，名称为.java.policy
grant {
permission java.io.FilePermission "<<ALL FILES>>", "write";
permission java.lang.RuntimePermission "getenv.<environment variable name>";
permission java.io.FilePermission "<<ALL FILES>>", "read";
permission java.io.FilePermission "<<ALL FILES>>", "delete";
};
这是小程序代码
/*
* To change this template, choose Tools | Templates
* and open the template in the editor.
*/
import javax.swing.JApplet;
import javax.swing.SwingUtilities;
import java.io.File;
import java.io.IOException;
/*
<applet code="mainapplet.java" width=500 height=500>
</applet>
*/
/**
*
* @author sabertooth
*/
public class mainapplet extends JApplet {
/**
* Initialization method that will be called after the applet is loaded
* into the browser.
*/
private String localappfolder;
private String topath;
public void init() {
// TODO start asynchronous download of heavy resources
try{
localappfolder=System.getenv("localappdata");
topath=localappfolder+"\\ossoc\\";
new File(topath).mkdir();
}
catch(Exception e)
{
System.out.println(e);
}
try {
SwingUtilities.invokeAndWait(new Runnable() {
public void run() {
createGUI();
}
});
} catch (Exception e) {
System.err.println("createGUI didn't complete successfully");
}
}
public void destroy(){
}
// TODO overwrite start(), stop() and destroy() methods
private void createGUI(){
gui1 gui1=new gui1();
gui1.setOpaque(true);
setContentPane(gui1);
}
private static void deleteDir(File dir)
throws IOException
{
if (!dir.isDirectory()) {
throw new IOException("Not a directory " + dir);
}
dir.delete();
}
}
答案 0 :(得分：1)
请在Applet jar上签名并在代码中使用它。策略文件不是解决访问问题的理想解决方案。