为什么我的applet在通过JavaScript访问方法时不能加载本地库?

Why can't my applet load a native library when accessing methods by JavaScript?

本文关键字:加载 不能 方法 访问 applet 我的 JavaScript 为什么      更新时间:2023-09-26

我有一个扫描文档的applet(使用JTwain)。我的applet由我编写的一个jar、几个第三方jar和一个dll(封装在JTwain jar中)组成。我打算加载applet,然后使用JavaScript访问applet的方法。然而,当我这样做时,我得到一个安全异常:

java.security.AccessControlException: access denied (java.lang.RuntimePermission loadLibrary.AspriseJTwain)
    at java.security.AccessControlContext.checkPermission(Unknown Source)
    at java.security.AccessController.checkPermission(Unknown Source)
    at java.lang.SecurityManager.checkPermission(Unknown Source)
    at java.lang.SecurityManager.checkLink(Unknown Source)
    at java.lang.Runtime.loadLibrary0(Unknown Source)
    at java.lang.System.loadLibrary(Unknown Source)
    at com.asprise.util.jtwain.SourceManager.init(SourceManager.java:222)
    at com.asprise.util.jtwain.SourceManager.<init>(SourceManager.java:36)
    at com.asprise.util.jtwain.SourceManager.instance(SourceManager.java:28)
    at co.altcom.cache.scanner.CacheScan.scanToPDF(CacheScan.java:91)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
    at java.lang.reflect.Method.invoke(Unknown Source)
    at sun.plugin.javascript.JSInvoke.invoke(Unknown Source)
    at sun.reflect.GeneratedMethodAccessor3.invoke(Unknown Source)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
    at java.lang.reflect.Method.invoke(Unknown Source)
    at sun.plugin.javascript.JSClassLoader.invoke(Unknown Source)
    at sun.plugin2.liveconnect.JavaClass$MethodInfo.invoke(Unknown Source)
    at sun.plugin2.liveconnect.JavaClass$MemberBundle.invoke(Unknown Source)
    at sun.plugin2.liveconnect.JavaClass.invoke0(Unknown Source)
    at sun.plugin2.liveconnect.JavaClass.invoke(Unknown Source)
    at sun.plugin2.main.client.LiveConnectSupport$PerAppletInfo$DefaultInvocationDelegate.invoke(Unknown Source)
    at sun.plugin2.main.client.LiveConnectSupport$PerAppletInfo$3.run(Unknown Source)
    at java.security.AccessController.doPrivileged(Native Method)
    at sun.plugin2.main.client.LiveConnectSupport$PerAppletInfo.doObjectOp(Unknown Source)
    at sun.plugin2.main.client.LiveConnectSupport$PerAppletInfo$LiveConnectWorker.run(Unknown Source)
    at java.lang.Thread.run(Unknown Source)

让我吃惊的是,我可以在applet的init方法中运行这些函数(没有例外- applet扫描并保存到计算机的文件系统)。只有当它们被JavaScript访问时才会失败。我猜我需要设置一些策略,但是我找不到关于它的任何信息。

任何想法?

将JS调用的代码包装在AccessController.doPrivileged(PrivilegedAction)(或重载变体)中