When I deployed a project in Apache Tomcat 6.0 it is working fine. When I deployed a same project in WebLogic Server 10.3 it’s showing an error:
Error 500--Internal Server Error
javax.servlet.ServletException: [HTTP:101249][weblogic.servlet.internal.WebAppServletContext@ae43b8 - appName: '_appsdir_ab_dir', name: 'ab', context-path: '/ab', spec-version: 'null']: Servlet class FirstServlet for servlet FirstServlet could not be loaded because the requested class was not found in the classpath .
java.lang.UnsupportedClassVersionError: FirstServlet : Unsupported major.minor version 51.0.
Your Weblogic is running (on) a JVM which is too low for the classfiles you’ve deployed on them. E.g. if you compile against JDK 1.7 you must run Weblogic on 1.7 (or newer, but none newer exist as of writing) as well.
So you should either recompile your classes (or chose another compiled package of the library if it’s a 3rd party library) against a lower JDK version, or get Weblogic to run against a higher JVM version.