Java Servlet引发load（）异常

我知道这个错误以前已经发布过，但是我不能理解堆栈跟踪，我希望有人能帮我

基本上，当我进入应用程序时，

getValue（“客户端”）

为空：

HttpSession validuser = request.getSession(); 

if (validuser.getValue("client") == null) {  
    response.sendRedirect("/profile/factfind/includes/session_timeout.jsp");
}

我认为这与以下错误有关：

2013-01-09 13:14:35 NamingContextListener[/Tomcat-Standalone/localhost/profile]: Creating JNDI naming context
2013-01-09 13:14:35 StandardManager[/profile]: Seeding random number generator class java.security.SecureRandom
2013-01-09 13:14:35 StandardManager[/profile]: Seeding of random number generator has been completed
2013-01-09 13:14:35 StandardContext[/profile]: Posting standard context attributes
2013-01-09 13:14:35 StandardContext[/profile]: Configuring application event listeners
2013-01-09 13:14:35 StandardContext[/profile]: Sending application start events
2013-01-09 13:14:35 StandardContext[/profile]: Starting filters
2013-01-09 13:14:35 StandardContext[/profile]: Starting completed
2013-01-09 13:14:37 StandardContext[/profile]: Servlet /profile threw load() exception
org.apache.jasper.JasperException: Unable to compile class for JSP

An error occurred at line: -1 in the jsp file: null

Generated servlet error:
    [javac] Compiling 1 source file



    at org.apache.jasper.compiler.DefaultErrorHandler.javacError(DefaultErrorHandler.java:85)
    at org.apache.jasper.compiler.ErrorDispatcher.javacError(ErrorDispatcher.java:248)
    at org.apache.jasper.compiler.Compiler.generateClass(Compiler.java:343)
    at org.apache.jasper.compiler.Compiler.compile(Compiler.java:356)
    at org.apache.jasper.JspCompilationContext.compile(JspCompilationContext.java:427)
    at org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:142)
    at org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:240)
    at org.apache.jasper.servlet.JspServlet.service(JspServlet.java:187)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:720)
    at org.apache.catalina.core.StandardWrapper.loadServlet(StandardWrapper.java:888)
    at org.apache.catalina.core.StandardWrapper.load(StandardWrapper.java:768)
    at org.apache.catalina.core.StandardContext.loadOnStartup(StandardContext.java:3484)
    at org.apache.catalina.core.StandardContext.start(StandardContext.java:3710)
    at org.apache.catalina.core.ContainerBase.addChildInternal(ContainerBase.java:777)
    at org.apache.catalina.core.ContainerBase.addChild(ContainerBase.java:760)
    at org.apache.catalina.core.StandardHost.addChild(StandardHost.java:538)
    at org.apache.catalina.core.StandardHostDeployer.addChild(StandardHostDeployer.java:667)
    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 org.apache.commons.beanutils.MethodUtils.invokeMethod(MethodUtils.java:216)
    at org.apache.commons.digester.SetNextRule.end(SetNextRule.java:217)
    at org.apache.commons.digester.Rule.end(Rule.java:253)
    at org.apache.commons.digester.Digester.endElement(Digester.java:1222)
    at org.apache.xerces.parsers.AbstractSAXParser.endElement(Unknown Source)
    at org.apache.xerces.impl.XMLDocumentFragmentScannerImpl.scanEndElement(Unknown Source)
    at org.apache.xerces.impl.XMLDocumentFragmentScannerImpl$FragmentContentDispatcher.dispatch(Unknown Source)
    at org.apache.xerces.impl.XMLDocumentFragmentScannerImpl.scanDocument(Unknown Source)
    at org.apache.xerces.parsers.XML11Configuration.parse(Unknown Source)
    at org.apache.xerces.parsers.DTDConfiguration.parse(Unknown Source)
    at org.apache.xerces.parsers.XMLParser.parse(Unknown Source)
    at org.apache.xerces.parsers.AbstractSAXParser.parse(Unknown Source)
    at org.apache.commons.digester.Digester.parse(Digester.java:1765)
    at org.apache.catalina.core.StandardHostDeployer.install(StandardHostDeployer.java:343)
    at org.apache.catalina.core.StandardHost.install(StandardHost.java:762)
    at org.apache.catalina.startup.HostConfig.deployDescriptors(HostConfig.java:443)
    at org.apache.catalina.startup.HostConfig.deployApps(HostConfig.java:377)
    at org.apache.catalina.startup.HostConfig.start(HostConfig.java:808)
    at org.apache.catalina.startup.HostConfig.lifecycleEvent(HostConfig.java:335)
    at org.apache.catalina.util.LifecycleSupport.fireLifecycleEvent(LifecycleSupport.java:120)
    at org.apache.catalina.core.ContainerBase.start(ContainerBase.java:1156)
    at org.apache.catalina.core.StandardHost.start(StandardHost.java:697)
    at org.apache.catalina.core.ContainerBase.start(ContainerBase.java:1148)
    at org.apache.catalina.core.StandardEngine.start(StandardEngine.java:311)
    at org.apache.catalina.core.StandardService.start(StandardService.java:450)
    at org.apache.catalina.core.StandardServer.start(StandardServer.java:2213)
    at org.apache.catalina.startup.Catalina.start(Catalina.java:484)
    at org.apache.catalina.startup.Catalina.execute(Catalina.java:371)
    at org.apache.catalina.startup.Catalina.process(Catalina.java:134)
    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 org.apache.catalina.startup.Bootstrap.main(Bootstrap.java:151)

会话存在于另一个应用程序中，然后加载“profile”，所以我不太确定当一个启动另一个时会发生什么

---

任何帮助都将不胜感激。谢谢。

似乎

getValue（String）

方法已被弃用。因此，请尝试以下代码

null==validuser.getAttribute（String）

我认为这是个问题

org.apache.jasper.JasperException: Unable to compile class for JSP

An error occurred at line: -1 in the jsp file: null

---

清理项目（或手动删除所有.class文件），然后尝试从头开始编译。如果错误消失-检查它是否可以工作。如果没有-你应该很明显地消除第一个错误。

结果表明，我的修复方法与一些论坛建议的相同。我在一个没有空格的目录（即

C:\Tomcat4.1

）中创建了一个新的Tomcat安装程序，并且运行正常

---

不知道为什么或者怎么做。你的代码片段是来自JSP还是servlet？我猜是JSP。请注意，堆栈跟踪指示无法编译JSP。有人认为HttpSession.getValue（）是一种不推荐使用的方法。尝试将此替换为“getAttribute（）”。已尝试。。。没有区别。这两个值都是空的。当我说它应该作为非弃用方法工作时，我的意思是相同的。我没有源代码。。。所以我不想删除所有的.class文件。这是一个web应用程序，我必须从Tomcat目录的复制和粘贴中部署：）你能想出任何方法来找到“null”jsp文件吗？你怎么说你没有源代码。那么编译什么呢？我有.class文件，但没有.java文件。