[jboss-user] [Beginner's Corner] - RestEasy - UnsupportedClassVersionError

Steve Jagels [https://community.jboss.org/people/sej] created the discussion "RestEasy - UnsupportedClassVersionError" To view the discussion, visit: https://community.jboss.org/message/731400#731400 -------------------------------------------------------------- I am trying to set up an example RestEasy application.  In web.xml I have restEasy scan turned off and am using the javax.ws.rs.Application: <listener>   <listener-class>org.jboss.resteasy.plugins.server.servlet.ResteasyBootstrap</listener-class> </listener> <servlet>   <servlet-name>Resteasy</servlet-name>   <servlet-class>org.jboss.resteasy.plugins.server.servlet.HttpServletDispatcher</servlet-class>   <init-param>     <param-name>javax.ws.rs.Application</param-name>     <param-value>com.mbh.esln.restdemo.action.HelloWorldApplication</param-value>   </init-param> </servlet> Then I have the class to deal with the singletons: package com.mbh.esln.restdemo.action; import java.util.HashSet; import java.util.Set; import javax.ws.rs.core.Application; import com.mbh.esln.restdemo.action.CustomersResource; public class HelloWorldApplication extends Application{     private Set<Object> singletons = new HashSet();     private Set<Class<?>> empty = new HashSet();     public HelloWorldApplication() {         // ADD YOUR RESTFUL RESOURCES HERE         this.singletons.add(new CustomersResource());         this.singletons.add(new Customer());         this.singletons.add(new GeoNames()); //        this.singletons.add(new GeoNamesService());         this.singletons.add(new GeoCode());         this.singletons.add(new RESTFulWSClientNoParam());     }     public Set<Class<?>> getClasses(){         return this.empty;     }     public Set<Object> getSingletons(){         return this.singletons;     } } But I still get this error when starting up jboss: 10:59:03,771 INFO  [TomcatDeployer] deploy, ctxPath=/testRestEasyWS, warUrl=.../deploy/testRestEasyWS.war/ 10:59:04,099 ERROR [MainDeployer] Could not create deployment: file:/C:/Java/jboss-4.3.0.GA_CP03/jboss-as/server/default/deploy/testrestdemo.war/ java.lang.UnsupportedClassVersionError: Bad version number in .class file I am using: jboss: 4.3.0.GA_CP03 jdk: 1.5.0_17 eclipse: 3.4 Any idea how to prevent this startup error? -------------------------------------------------------------- Reply to this message by going to Community [https://community.jboss.org/message/731400#731400] Start a new discussion in Beginner's Corner at Community [https://community.jboss.org/choose-container!input.jspa?contentType=1&...]