我们的团队有一个在Oracle JRE 7u5中运行良好的applet。将JRE更新为7u6或7u7后，applet无法初始化。类加载器在加载log4j类时抛出异常：
Caused by: java.lang.IllegalStateException: zip file closed
at java.util.zip.ZipFile.ensureOpen(Unknown Source)
at java.util.zip.ZipFile.getEntry(Unknown Source)
at java.util.jar.JarFile.getEntry(Unknown Source)
at java.util.jar.JarFile.getJarEntry(Unknown Source)
at com.sun.deploy.security.DeployURLClassPath$JarLoader.getResource(Unknown Source)
at com.sun.deploy.security.DeployURLClassPath.getResource(Unknown Source)
at sun.plugin2.applet.Plugin2ClassLoader$2.run(Unknown Source)
at java.security.AccessController.doPrivileged(Native Method)
at sun.plugin2.applet.Plugin2ClassLoader.findClassHelper(Unknown Source)
at sun.plugin2.applet.Applet2ClassLoader.findClass(Unknown Source)
at sun.plugin2.applet.Plugin2ClassLoader.loadClass0(Unknown Source)
at sun.plugin2.applet.Plugin2ClassLoader.loadClass(Unknown Source)
at sun.plugin2.applet.Plugin2ClassLoader.loadClass0(Unknown Source)
at sun.plugin2.applet.Plugin2ClassLoader.loadClass(Unknown Source)
at sun.plugin2.applet.Plugin2ClassLoader.loadClass(Unknown Source)
at java.lang.ClassLoader.loadClass(Unknown Source)
at java.lang.Class.forName0(Native Method)
at java.lang.Class.forName(Unknown Source)
at org.apache.log4j.PropertyConfigurator.class$(PropertyConfigurator.java:572)
at org.apache.log4j.PropertyConfigurator.parseAppender(PropertyConfigurator.java:752)
at org.apache.log4j.PropertyConfigurator.parseCategory(PropertyConfigurator.java:735)
at org.apache.log4j.PropertyConfigurator.configureRootCategory(PropertyConfigurator.java:615)
at org.apache.log4j.PropertyConfigurator.doConfigure(PropertyConfigurator.java:502)
at org.apache.log4j.PropertyConfigurator.doConfigure(PropertyConfigurator.java:547)
at org.apache.log4j.helpers.OptionConverter.selectAndConfigure(OptionConverter.java:483)
at org.apache.log4j.LogManager.<clinit>(LogManager.java:127)
还有其他人观察过这种行为吗？