我提到了一个小演示.在
Setting up policies for an Applet embedded in HTML&一位Iced Tea JRE用户评论了该演示.失败了
为他们.他们拒绝了对applet的许可(因此将其限制在沙盒中)&应该看到
绿色的“此小程序是沙盒”页面.相反,小程序完全失败了,他们看到了“灰色空间”
小程序应该在的位置.
我警告说,它试图实例化一个与众不同的File对象.即
Sun / Oracle JRE将允许它没有问题,只抛出一个安全异常
当applet尝试创建JFileChooser时. OTOH冰茶JRE不允许
要创建的文件.
因此,此代码应解决该问题.它移动了创建/添加
JEditorPane和1st的安装
一条“其他所有失败”消息,然后是绿色的“沙盒”页面,直到新File(..)调用之前.
我的问题是.对于使用Iced Tea JRE的用户,此代码是否“按广告规定工作”？
要测试它：
>在以下位置访问小程序
pscode.org/test/docload/applet-latest.html
>拒绝数字签名的代码.这对于创造正确的权利非常重要
测试applet的条件.
>观察/报告小程序是否加载了绿色
sandbox.html.沙盒
文档将表示修复该错误的“成功”.
同样有趣的是(可能几乎没有)
Demo of Defensive Loading of Trusted Applets,其中链接
到小程序页面,小程序中显示的每个HTML文件以及一个包含
代码的来源HTML和Ant build.xml,这样您就可以“孩子们在家完成此操作”.
这是新代码.
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()");
}
}
解决方法:
这是java.stderr的输出(相当于Java控制台的一半-另一半是java.stdout,在您的情况下为空)：
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
因此,如果我在对话框中按“取消”,则看起来甚至没有加载您的applet代码.
我认为您在Java方面无能为力-也许使用其他签名过程或通过JNLP启动applet会有所帮助.或在IcedTea上提交错误报告.
为了演示这一点,我通过省略了applet中的所有关键内容,创建了一个真正的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.");
}
}
我对此进行了编译,并修改了HTML文件以使用它,它给出了完全相同的症状.
当用户按下“取消”时,IcedTea似乎已经重新定义了操作.公平地说,对话框中的按钮是“运行”和“取消”,而不是“使用所有权限运行”和“运行沙盒”.
(在Sun的对话框中,有相同的按钮,但实际上它们的含义不是所要求的.)