java.lang.NoClassDefFoundError: javax/servlet/jsp/jstl/core/ConditionalTagSupport

问题

While I am deploying and runing my web application on Apache Tomcat in Eclipse IDE

I've included the JSTL1.2.jar, jstl-impl.jar.

I'm really wondering how to get this fixed. The same deployment works perfectly fine on Weblogic server(on PROD environment)

Exception stack trace:

INFO: Starting Servlet Engine: Apache Tomcat/7.0.12
Feb 10, 2014 6:40:29 PM org.apache.catalina.core.ApplicationContext log
SEVERE: StandardWrapper.Throwable
java.lang.NoClassDefFoundError: javax/servlet/jsp/jstl/core/ConditionalTagSupport
    at java.lang.ClassLoader.defineClass1(Native Method)
    at java.lang.ClassLoader.defineClassCond(ClassLoader.java:631)
    at java.lang.ClassLoader.defineClass(ClassLoader.java:615)
    at java.security.SecureClassLoader.defineClass(SecureClassLoader.java:141)
    at org.apache.catalina.loader.WebappClassLoader.findClassInternal(WebappClassLoader.java:2818)
    at org.apache.catalina.loader.WebappClassLoader.findClass(WebappClassLoader.java:1148)
    at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1643)
    at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1521)
    at org.apache.jasper.compiler.Parser.parseCustomTag(Parser.java:1223)
    at org.apache.jasper.compiler.Parser.parseElements(Parser.java:1450)
    at org.apache.jasper.compiler.Parser.parse(Parser.java:138)

回答1:

I would check a number of things:

1) That the jar files are sitting in the lib folder under WEB-INF and not just referenced in the build path. 2) That the tomcat 7 runtime library is included in your build path 3) I'd check the web.xml file and ensure that I'm complying to a spec higher than or equal to 2.5.

If you provide more details with your project setup it might be easier to answer.

来源：https://stackoverflow.com/questions/21678492/java-lang-noclassdeffounderror-javax-servlet-jsp-jstl-core-conditionaltagsuppor