关于在Eclipse中无法使用EL的问题

[半生的救赎]

一旦在Eclipse中使用表达式，JSP就会报错：

HTTP Status 500 - java.lang.NoClassDefFoundError: Could not initialize class org.apache.jasper.el.ELContextImpl

type Exception report

message java.lang.NoClassDefFoundError: Could not initialize class org.apache.jasper.el.ELContextImpl

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

exception

javax.servlet.ServletException: java.lang.NoClassDefFoundError: Could not initialize class org.apache.jasper.el.ELContextImpl
org.apache.jasper.servlet.JspServlet.service(JspServlet.java:348)
javax.servlet.http.HttpServlet.service(HttpServlet.java:731)
org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)
root cause

java.lang.NoClassDefFoundError: Could not initialize class org.apache.jasper.el.ELContextImpl
org.apache.jasper.compiler.Validator$ValidateVisitor.prepareExpression(Validator.java:1618)
org.apache.jasper.compiler.Validator$ValidateVisitor.visit(Validator.java:748)
org.apache.jasper.compiler.Node$ELExpression.accept(Node.java:968)
org.apache.jasper.compiler.Node$Nodes.visit(Node.java:2392)
org.apache.jasper.compiler.Node$Visitor.visitBody(Node.java:2444)
org.apache.jasper.compiler.Node$Visitor.visit(Node.java:2450)
org.apache.jasper.compiler.Node$Root.accept(Node.java:474)
org.apache.jasper.compiler.Node$Nodes.visit(Node.java:2392)
org.apache.jasper.compiler.Validator.validateExDirectives(Validator.java:1845)
org.apache.jasper.compiler.Compiler.generateJava(Compiler.java:218)
org.apache.jasper.compiler.Compiler.compile(Compiler.java:374)
org.apache.jasper.compiler.Compiler.compile(Compiler.java:354)
org.apache.jasper.compiler.Compiler.compile(Compiler.java:341)
org.apache.jasper.JspCompilationContext.compile(JspCompilationContext.java:663)
org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:364)
org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:395)
org.apache.jasper.servlet.JspServlet.service(JspServlet.java:339)
javax.servlet.http.HttpServlet.service(HttpServlet.java:731)
org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)
note The full stack trace of the root cause is available in the Apache Tomcat/7.0.79 logs.


有没有大神帮忙找一下原因。（注：myeclipse没试过，但是使用文本编辑器编辑时使用EL能正常使用）

[G.Jagger]

java.lang.NoClassDefFoundError: Could not initialize class org.apache.jasper.el.ELContextImpl 找不到这个类，是不是jar包缺失了

[枫舞蝶刺]

有关 jasper servlet的jar 缺失或冲突了吧