我收到以下错误：
06/08/2011 02:56:33 org.apache.catalina.core.StandardWrapperValve invoke
SEVERE: Servlet.service() for servlet UploadTheme threw exception
java.lang.NoClassDefFoundError: javax/servlet/http/HttpServletRequest
at org.apache.commons.fileupload.servlet.ServletRequestContext.getContentType(ServletRequestContext.java:73)
at org.apache.commons.fileupload.FileUploadBase$FileItemIteratorImpl.<init>(FileUploadBase.java:905)
at org.apache.commons.fileupload.FileUploadBase.getItemIterator(FileUploadBase.java:331)
at org.apache.commons.fileupload.FileUploadBase.parseRequest(FileUploadBase.java:351)
at org.apache.commons.fileupload.servlet.ServletFileUpload.parseRequest(ServletFileUpload.java:126)
at cs236369.hw5.servlets.xml.UploadTheme.doPost(UploadTheme.java:47)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:637)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:717)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:290)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:233)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:191)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:127)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:102)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:109)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:298)
at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:859)
at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.java:588)
at org.apache.tomcat.util.net.JIoEndpoint$Worker.run(JIoEndpoint.java:489)
at java.lang.Thread.run(Unknown Source)
I place JARS under WEB-INF/lib. Here's what the project classpath looks like:
And here's the run configuration:
当我添加 FileUpload 时，问题就开始了。
知道出了什么问题吗？
您不需要在服务器的运行配置中使用 commons-upload jar 文件。我怀疑这就是这个问题的原因，因为加载文件上传类的类加载器和尝试加载 servlet 特定类的类加载器之间存在一些类可见性问题。
您应该删除它并将其保留为 WEB-INF/lib 的一部分。希望这能解决您的问题。