Estou tendo dificuldade em rodar o Spring WEB MVC em JRE 1.5.
Em 1.6 tá rodando uma maravilha mas o servidor que vai rodar a aplicação é JRE 1.5 
Esta dando esse erro:
HTTP Status 500 -
type Exception report
message
description The server encountered an internal error () that prevented it from fulfilling this request.
exception
javax.servlet.ServletException: Servlet.init() for servlet front threw exception
org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:105)
org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:148)
org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:869)
org.apache.coyote.http11.Http11BaseProtocol$Http11ConnectionHandler.processConnection(Http11BaseProtocol.java:664)
org.apache.tomcat.util.net.PoolTcpEndpoint.processSocket(PoolTcpEndpoint.java:527)
org.apache.tomcat.util.net.LeaderFollowerWorkerThread.runIt(LeaderFollowerWorkerThread.java:80)
org.apache.tomcat.util.threads.ThreadPool$ControlRunnable.run(ThreadPool.java:684)
java.lang.Thread.run(Thread.java:595)
root cause
org.springframework.beans.factory.CannotLoadBeanClassException: Error loading class [controllers.PrincipalController] for bean with name '/principal.java' defined in ServletContext resource [/WEB-INF/front-servlet.xml]: problem with class file or dependent class; nested exception is java.lang.UnsupportedClassVersionError: Bad version number in .class file
org.springframework.beans.factory.support.AbstractBeanFactory.resolveBeanClass(AbstractBeanFactory.java:1139)
org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:282)
org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:689)
org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:358)
org.springframework.web.servlet.FrameworkServlet.createWebApplicationContext(FrameworkServlet.java:329)
org.springframework.web.servlet.FrameworkServlet.initWebApplicationContext(FrameworkServlet.java:265)
org.springframework.web.servlet.FrameworkServlet.initServletBean(FrameworkServlet.java:235)
org.springframework.web.servlet.HttpServletBean.init(HttpServletBean.java:126)
javax.servlet.GenericServlet.init(GenericServlet.java:211)
org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:105)
org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:148)
org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:869)
org.apache.coyote.http11.Http11BaseProtocol$Http11ConnectionHandler.processConnection(Http11BaseProtocol.java:664)
org.apache.tomcat.util.net.PoolTcpEndpoint.processSocket(PoolTcpEndpoint.java:527)
org.apache.tomcat.util.net.LeaderFollowerWorkerThread.runIt(LeaderFollowerWorkerThread.java:80)
org.apache.tomcat.util.threads.ThreadPool$ControlRunnable.run(ThreadPool.java:684)
java.lang.Thread.run(Thread.java:595)
root cause
java.lang.UnsupportedClassVersionError: Bad version number in .class file
java.lang.ClassLoader.defineClass1(Native Method)
java.lang.ClassLoader.defineClass(ClassLoader.java:620)
java.security.SecureClassLoader.defineClass(SecureClassLoader.java:124)
org.apache.catalina.loader.WebappClassLoader.findClassInternal(WebappClassLoader.java:1812)
org.apache.catalina.loader.WebappClassLoader.findClass(WebappClassLoader.java:866)
org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1319)
org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1198)
org.springframework.util.ClassUtils.forName(ClassUtils.java:201)
org.springframework.beans.factory.support.AbstractBeanDefinition.resolveBeanClass(AbstractBeanDefinition.java:333)
org.springframework.beans.factory.support.AbstractBeanFactory.resolveBeanClass(AbstractBeanFactory.java:1133)
org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:282)
org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:689)
org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:358)
org.springframework.web.servlet.FrameworkServlet.createWebApplicationContext(FrameworkServlet.java:329)
org.springframework.web.servlet.FrameworkServlet.initWebApplicationContext(FrameworkServlet.java:265)
org.springframework.web.servlet.FrameworkServlet.initServletBean(FrameworkServlet.java:235)
org.springframework.web.servlet.HttpServletBean.init(HttpServletBean.java:126)
javax.servlet.GenericServlet.init(GenericServlet.java:211)
org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:105)
org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:148)
org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:869)
org.apache.coyote.http11.Http11BaseProtocol$Http11ConnectionHandler.processConnection(Http11BaseProtocol.java:664)
org.apache.tomcat.util.net.PoolTcpEndpoint.processSocket(PoolTcpEndpoint.java:527)
org.apache.tomcat.util.net.LeaderFollowerWorkerThread.runIt(LeaderFollowerWorkerThread.java:80)
org.apache.tomcat.util.threads.ThreadPool$ControlRunnable.run(ThreadPool.java:684)
java.lang.Thread.run(Thread.java:595)
note The full stack trace of the root cause is available in the Apache Tomcat/5.5.17 logs.
Apache Tomcat/5.5.17
Estou usando Netbeans 5.5.
Eu comecei desenvolvendo em JDK 1.6. Eu configurei tdo o Netbeans para usar JDK 1.5.
Cheguei a criar um novo projeto direto em JDK 1.5.
