Failed to load or instantiate TagLibraryValidator class: org.apache.taglibs.standard.tlv.JstlCoreTLV

i will building the gateway plugin in tomcat5.5 , show the Exception :

org.apache.jasper.JasperException: Unable to read TLD “META-INF/c-1_0-rt.tld” from JAR file “file:/C:/Program Files/Apache Software Foundation/Tomcat 5.5/webapps/gateTest/WEB-INF/lib/jstl-1.2.jar”: org.apache.jasper.JasperException: Failed to load or instantiate TagLibraryValidator class: org.apache.taglibs.standard.tlv.JstlCoreTLV
org.apache.jasper.servlet.JspServletWrapper.handleJspException(JspServletWrappe r.java:510)
org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:375)
org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:314)
org.apache.jasper.servlet.JspServlet.service(JspServlet.java:264)
javax.servlet.http.HttpServlet.service(HttpServlet.java:802)

does anyone know why? waiting helping…