初学myecplise+web_project+tomcat6.0报错问题

初学myecplise+web_project+tomcat6.0报错问题
哪位大神帮忙看一下
信息: SessionListener: contextInitialized()
2016-5-17 10:27:23 org.apache.catalina.startup.HostConfig deployDirectory
信息: Deploying web application directory JFDemo
2016-5-17 10:27:23 org.apache.catalina.loader.WebappClassLoader validateJarFile
信息: validateJarFile(F:tomcat-6.0webappsJFDemoWEB-INFlibjetty-server-6.1.26.jar) - jar not loaded. See Servlet Spec 2.3, section 9.7.2. Offending class: javax/servlet/Servlet.class
2016-5-17 10:27:24 org.apache.catalina.core.StandardContext filterStart
严重: Exception starting filter jfinal
java.lang.Error: Unresolved compilation problem:
The method setDevMode(boolean) in the type Constants is not applicable for the arguments (Boolean)

at com.demo.common.DemoConfig.configConstant(DemoConfig.java:26)
at com.jfinal.core.Config.configJFinal(Config.java:44)
at com.jfinal.core.JFinal.init(JFinal.java:66)
at com.jfinal.core.JFinalFilter.init(JFinalFilter.java:48)
at org.apache.catalina.core.ApplicationFilterConfig.getFilter(ApplicationFilterConfig.java:295)