java.lang.NoClassDefFoundError: javax/servlet/http/HttpServlet是什么问题？
HTTP   Status   500   -  

--------------------------------------------

type   Exception   report

message  

description   The   server   encountered   an   internal   error   ()   that   prevented   it   from   fulfilling   this   request.

exception  

javax.servlet.ServletException:   Error   allocating   a   servlet   instance
org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:118)
org.apache.coyote.tomcat5.CoyoteAdapter.service(CoyoteAdapter.java:160)
org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:799)
org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.processConnection(Http11Protocol.java:705)
org.apache.tomcat.util.net.TcpWorkerThread.runIt(PoolTcpEndpoint.java:577)
org.apache.tomcat.util.threads.ThreadPool$ControlRunnable.run(ThreadPool.java:683)
java.lang.Thread.run(Thread.java:595)


root   cause  

java.lang.NoClassDefFoundError:   javax/servlet/http/HttpServlet
java.lang.ClassLoader.defineClass1(Native   Method)
java.lang.ClassLoader.defineClass(ClassLoader.java:620)
java.security.SecureClassLoader.defineClass(SecureClassLoader.java:124)
java.net.URLClassLoader.defineClass(URLClassLoader.java:260)
java.net.URLClassLoader.access$100(URLClassLoader.java:56)
java.net.URLClassLoader$1.run(URLClassLoader.java:195)
java.security.AccessController.doPrivileged(Native   Method)
java.net.URLClassLoader.findClass(URLClassLoader.java:188)
java.lang.ClassLoader.loadClass(ClassLoader.java:306)
sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:268)
java.lang.ClassLoader.loadClass(ClassLoader.java:251)
org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1255)
org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1189)
org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:118)
org.apache.coyote.tomcat5.CoyoteAdapter.service(CoyoteAdapter.java:160)
org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:799)
org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.processConnection(Http11Protocol.java:705)
org.apache.tomcat.util.net.TcpWorkerThread.runIt(PoolTcpEndpoint.java:577)
org.apache.tomcat.util.threads.ThreadPool$ControlRunnable.run(ThreadPool.java:683)
java.lang.Thread.run(Thread.java:595)


------解决方案--------------------
Error allocating a servlet instance
分配一个SERVLET实例时错误
java.lang.NoClassDefFoundError: javax/servlet/http/HttpServlet
没有找到对应的CLASS定义吧...
应该可能是你的SERVLET类有错误吧.导致无法实例化一个SERVLET类
等高手了..哈哈

我的异常网推荐解决方案：The server encountered an internal error () that prevented it from fulfilling this request.,http://www.aiyiweb.com/java-web/317.html