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Does this applet work in Jced Tea JED?

I mentioned a small demonstration. in Setting up policies for an applet embedded in HTML , and the user of the Jced Tea JRE commented on this demo. failed for them. They refused permission for the applet (thereby restricting it to the sandbox) and were purported to see the green color of this applet with sand. Instead, the applet completely failed, and they saw the “gray space” where the applet was supposed to be.

I WAGING that he was trying to instantiate a File object, which is the difference. I.E. The Sun / Oracle JRE will resolve it without problems by eliminating a security exception when the applet tries to create a JFileChooser . OTOH Iced Tea JRE does not allow File .

Therefore, this code should fix this problem. It moves the creation / addition of JEditorPane and setting the 1st message “everything else fails”, and then the green “sand” page, before calling new File(..) .

My question is. Does this code "work as advertised" for users with the Iced Tea JRE?

To check this:

  • Visit the applet at pscode.org/test/docload/applet-latest.html
  • Refuse digitally signed code. It is very important to create the right conditions for checking the applet.
  • Observe / report if the applet is loading the green color of sandbox.html . A sandboxed document will represent "success" in correcting a mistake.

Also interesting (which may be small) is the home page for the Demo Download of trusted applets , in which links to applet pages, each of the HTML files displayed in the applet, and a ZIP archive containing the source code and HTML, as well as Ant build. xml so you can "do it at home, kids."

Here is the new code.

 package org.pscode.eg.docload; import java.awt.BorderLayout; import java.awt.event.ActionListener; import java.awt.event.ActionEvent; import javax.swing.JApplet; import javax.swing.JButton; import javax.swing.JEditorPane; import javax.swing.JPanel; import javax.swing.JScrollPane; import javax.swing.JFileChooser; import java.net.URL; import java.net.MalformedURLException; import java.io.File; import java.io.IOException; import java.security.AccessControlException; /** An applet to display documents that are JEditorPane compatible. This applet loads in a defensive way in terms of the security environment, in case the user has refused to accept the digitally signed code. */ public class DocumentLoader extends JApplet { JEditorPane document; @Override public void init() { System.out.println("init()"); JPanel main = new JPanel(); main.setLayout( new BorderLayout() ); getContentPane().add(main); document = new JEditorPane("text/html", "<html><body><h1>Testing</h1><p>Testing security environment.."); main.add( new JScrollPane(document), BorderLayout.CENTER ); System.out.println("init(): entering 'try'"); try { // set up the green 'sandboxed URL', as a precaution.. URL sandboxed = new URL(getDocumentBase(), "sandbox.html"); document.setPage( sandboxed ); // It might seem odd that a sandboxed applet can /instantiate/ // a File object, but until it goes to do anything with it, the // JVM considers it 'OK'. Until we go to do anything with a // 'File' object, it is really just a filename. System.out.println("init(): instantiate file"); File f = new File("."); System.out.println("init(): file instantiated, create file chooser"); // Everything above here is possible for a sandboxed applet // *test* if this applet is sandboxed final JFileChooser jfc = new JFileChooser(f); // invokes security check jfc.setFileSelectionMode(JFileChooser.FILES_ONLY); jfc.setMultiSelectionEnabled(false); System.out.println( "init(): file chooser created, " + "create/add 'Load Document' button"); JButton button = new JButton("Load Document"); button.addActionListener( new ActionListener(){ public void actionPerformed(ActionEvent ae) { int result = jfc.showOpenDialog( DocumentLoader.this); if ( result==JFileChooser.APPROVE_OPTION ) { File temp = jfc.getSelectedFile(); try { URL page = temp.toURI().toURL(); document.setPage( page ); } catch(Exception e) { e.printStackTrace(); } } } } ); main.add( button, BorderLayout.SOUTH ); // the applet is trusted, change to the red 'welcome page' URL trusted = new URL(getDocumentBase(), "trusted.html"); document.setPage(trusted); } catch (MalformedURLException murle) { murle.printStackTrace(); document.setText( murle.toString() ); } catch (IOException ioe) { ioe.printStackTrace(); document.setText( ioe.toString() ); } catch (AccessControlException ace) { ace.printStackTrace(); // document should already be showing sandbox.html } } @Override public void start() { System.out.println("start()"); } @Override public void stop() { System.out.println("stop()"); } @Override public void destroy() { System.out.println("destroy()"); } }
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Here is the result on java.stderr (one half equivalent to the Java console, the other half java.stdout , which is empty in your case):

 net.sourceforge.jnlp.LaunchException: Fatal: Initialization Error: Could not initialize applet. at net.sourceforge.jnlp.Launcher.createApplet(Launcher.java:604) at net.sourceforge.jnlp.Launcher.getApplet(Launcher.java:548) at net.sourceforge.jnlp.Launcher$TgThread.run(Launcher.java:729) Caused by: net.sourceforge.jnlp.LaunchException: Fatal: Launch Error: Jars not verified. at net.sourceforge.jnlp.runtime.JNLPClassLoader.checkTrustWithUser(JNLPClassLoader.java:467) at net.sourceforge.jnlp.runtime.JNLPClassLoader.initializeResources(JNLPClassLoader.java:410) at net.sourceforge.jnlp.runtime.JNLPClassLoader.<init>(JNLPClassLoader.java:168) at net.sourceforge.jnlp.runtime.JNLPClassLoader.getInstance(JNLPClassLoader.java:249) at net.sourceforge.jnlp.Launcher.createApplet(Launcher.java:575) ... 2 more Caused by: net.sourceforge.jnlp.LaunchException: Fatal: Launch Error: Jars not verified. at net.sourceforge.jnlp.runtime.JNLPClassLoader.checkTrustWithUser(JNLPClassLoader.java:467) at net.sourceforge.jnlp.runtime.JNLPClassLoader.initializeResources(JNLPClassLoader.java:410) at net.sourceforge.jnlp.runtime.JNLPClassLoader.<init>(JNLPClassLoader.java:168) at net.sourceforge.jnlp.runtime.JNLPClassLoader.getInstance(JNLPClassLoader.java:249) at net.sourceforge.jnlp.Launcher.createApplet(Launcher.java:575) at net.sourceforge.jnlp.Launcher.getApplet(Launcher.java:548) at net.sourceforge.jnlp.Launcher$TgThread.run(Launcher.java:729) java.lang.NullPointerException at net.sourceforge.jnlp.NetxPanel.runLoader(NetxPanel.java:99) at sun.applet.AppletPanel.run(AppletPanel.java:380) at java.lang.Thread.run(Thread.java:636) java.lang.NullPointerException at sun.applet.AppletPanel.run(AppletPanel.java:430) at java.lang.Thread.run(Thread.java:636) java.lang.Exception: Applet initialization timeout at sun.applet.PluginAppletViewer.handleMessage(PluginAppletViewer.java:637) at sun.applet.PluginStreamHandler.handleMessage(PluginStreamHandler.java:270) at sun.applet.PluginMessageHandlerWorker.run(PluginMessageHandlerWorker.java:82) java.lang.RuntimeException: Failed to handle message: handle 60822154 for instance 2 at sun.applet.PluginAppletViewer.handleMessage(PluginAppletViewer.java:660) at sun.applet.PluginStreamHandler.handleMessage(PluginStreamHandler.java:270) at sun.applet.PluginMessageHandlerWorker.run(PluginMessageHandlerWorker.java:82) Caused by: java.lang.Exception: Applet initialization timeout at sun.applet.PluginAppletViewer.handleMessage(PluginAppletViewer.java:637) ... 2 more

So, it looks like your applet code has not yet been loaded if you click Cancel in the dialog box.

confirmation dialog

I think you can’t do anything here on the Java side - perhaps using a different signing procedure or running the JNLP applet will help. Or file a bug report on IcedTea.

To demonstrate this, I created a real simple applet, omitting everything critical from your applet:

 package org.pscode.eg.docload; import java.awt.FlowLayout; import javax.swing.*; public class Example extends JApplet { JLabel label; public void init() { System.out.println("init()"); SwingUtilities.invokeLater(new Runnable(){public void run() { label = new JLabel("inited."); getContentPane().setLayout(new FlowLayout()); getContentPane().add(label); }}); } @Override public void start() { System.out.println("start()"); label.setText("started."); } @Override public void stop() { System.out.println("stop()"); label.setText("stopped."); } @Override public void destroy() { System.out.println("destroy()"); label.setText("destroyed."); } }

I compiled this and modified your HTML file to use it instead, and it gives exactly the same symptoms.

IcedTea seems to have redefined what to do when the user clicks cancel. It is fair to say that the buttons in the dialog box are “Run” and “Cancel”, and not “Run with all permissions” and “Run stand-alone.”

(There are the same buttons in the Sun dialog box, but in reality they mean something different than what is set.)

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For reference, I can confirm @ Paŭlo Ebermann's results using IcedTea 1.9.7 on Ubuntu 10.04:

  $ java -version
 java version "1.6.0_20"
 OpenJDK Runtime Environment (IcedTea6 1.9.7) (6b20-1.9.7-0ubuntu1 ~ 10.04.1)
 OpenJDK Client VM (build 19.0-b09, mixed mode, sharing)

appletviewer shows the expected sandbox and fllowing diagnostic output. Firefox on Ubuntu only offers Run (trusted) or Cancel (nothing).

  $ appletviewer http://pscode.org/test/docload/applet-latest.html
 Warning: Can't read AppletViewer properties file: ... Using defaults.
 init ()
 init (): entering 'try'
 init (): instantiate file
 init (): file instantiated, create file chooser
 java.security.AccessControlException: access denied (java.util.PropertyPermission user.home read)
     at java.security.AccessControlContext.checkPermission (AccessControlContext.javahaps93)
     at java.security.AccessController.checkPermission (AccessController.java∗53)
     at java.lang.SecurityManager.checkPermission (SecurityManager.java∗49)
     at java.lang.SecurityManager.checkPropertyAccess (SecurityManager.java:1302)
     at java.lang.System.getProperty (System.java:669)
     at javax.swing.filechooser.FileSystemView.getHomeDirectory (FileSystemView.javahaps97)
     at javax.swing.plaf.metal.MetalFileChooserUI.installComponents (MetalFileChooserUI.java:282)
     at javax.swing.plaf.basic.BasicFileChooserUI.installUI (BasicFileChooserUI.java:153)
     at javax.swing.plaf.metal.MetalFileChooserUI.installUI (MetalFileChooserUI.java:155)
     at javax.swing.JComponent.setUI (JComponent.java:651)
     at javax.swing.JFileChooser.updateUI (JFileChooser.java:1781)
     at javax.swing.JFileChooser.setup (JFileChooser.javahaps74)
     at javax.swing.JFileChooser. (JFileChooser.javahaps47)
     at javax.swing.JFileChooser. (JFileChooser.javahaps30)
     at org.pscode.eg.docload.DocumentLoader.init (DocumentLoader.java:57)
     at sun.applet.AppletPanel.run (AppletPanel.java:436)
     at java.lang.Thread.run (Thread.java:636)
 start ()
 stop ()
 destroy ()

On Mac OS X, Safari 5.05 gives the expected results; and appletviewer produces comparable but not identical output.

  $ java -version
 java version "1.6.0_24"
 Java (TM) SE Runtime Environment (build 1.6.0_24-b07-334-9M3326)
 Java HotSpot (TM) 64-Bit Server VM (build 19.1-b02-334, mixed mode)

 $ appletviewer http://pscode.org/test/docload/applet-latest.html
 init ()
 init (): entering 'try'
 init (): instantiate file
 init (): file instantiated, create file chooser
 java.security.AccessControlException: access denied (java.io.FilePermission. read)
     at java.security.AccessControlContext.checkPermission (AccessControlContext.javahaps74)
     at java.security.AccessController.checkPermission (AccessController.java∗46)
     at java.lang.SecurityManager.checkPermission (SecurityManager.java∗32)
     at java.lang.SecurityManager.checkRead (SecurityManager.java:871)
     at java.io.File.exists (File.java:731)
     at javax.swing.JFileChooser.setCurrentDirectory (JFileChooser.java∗48)
     at javax.swing.JFileChooser. (JFileChooser.javahaps34)
     at javax.swing.JFileChooser. (JFileChooser.java data16)
     at org.pscode.eg.docload.DocumentLoader.init (DocumentLoader.java:57)
     at sun.applet.AppletPanel.run (AppletPanel.java:424)
     at java.lang.Thread.run (Thread.java:680)
 start ()
 stop ()
 destroy ()
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Source: https://habr.com/ru/post/1333340/

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