Jfinal启动出错

新手刚开始使用。网上查询资料，说是idea不适用 JFinal.start("WebRoot", 80, "/",5);带参。eclipse使用。但是我的就是eclipse。去掉5这个参数好使

java.lang.IllegalAccessError: class sun.reflect.GeneratedConstructorAccessor7 cannot access its superclass sun.reflect.ConstructorAccessorImpl

at sun.misc.Unsafe.defineClass(Native Method)

at sun.reflect.ClassDefiner.defineClass(Unknown Source)

at sun.reflect.MethodAccessorGenerator$1.run(Unknown Source)

at java.security.AccessController.doPrivileged(Native Method)

at sun.reflect.MethodAccessorGenerator.generate(Unknown Source)

at sun.reflect.MethodAccessorGenerator.generateConstructor(Unknown Source)

at sun.reflect.NativeConstructorAccessorImpl.newInstance(Unknown Source)

at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(Unknown Source)

at java.lang.reflect.Constructor.newInstance(Unknown Source)

at com.mysql.jdbc.Util.handleNewInstance(Util.java:425)

at com.mysql.jdbc.ResultSetImpl.getInstance(ResultSetImpl.java:342)

at com.mysql.jdbc.MysqlIO.buildResultSetWithRows(MysqlIO.java:3129)

at com.mysql.jdbc.MysqlIO.getResultSet(MysqlIO.java:476)

at com.mysql.jdbc.MysqlIO.readResultsForQueryOrUpdate(MysqlIO.java:3112)

at com.mysql.jdbc.MysqlIO.readAllResults(MysqlIO.java:2341)

at com.mysql.jdbc.MysqlIO.sqlQueryDirect(MysqlIO.java:2736)

at com.mysql.jdbc.ConnectionImpl.execSQL(ConnectionImpl.java:2483)

at com.mysql.jdbc.ConnectionImpl.execSQL(ConnectionImpl.java:2441)

at com.mysql.jdbc.StatementImpl.executeQuery(StatementImpl.java:1381)

at com.mchange.v2.c3p0.impl.NewProxyStatement.executeQuery(NewProxyStatement.java:327)

at com.jfinal.plugin.activerecord.TableBuilder.doBuild(TableBuilder.java:71)

at com.jfinal.plugin.activerecord.TableBuilder.build(TableBuilder.java:47)

at com.jfinal.plugin.activerecord.ActiveRecordPlugin.start(ActiveRecordPlugin.java:226)

at com.jfinal.core.Config.startPlugins(Config.java:107)

at com.jfinal.core.Config.configJFinal(Config.java:51)

at com.jfinal.core.JFinal.init(JFinal.java:63)

at com.jfinal.core.JFinalFilter.init(JFinalFilter.java:49)

at org.eclipse.jetty.servlet.FilterHolder.doStart(FilterHolder.java:119)

at org.eclipse.jetty.util.component.AbstractLifeCycle.start(AbstractLifeCycle.java:64)

at org.eclipse.jetty.servlet.ServletHandler.initialize(ServletHandler.java:724)

at org.eclipse.jetty.servlet.ServletContextHandler.startContext(ServletContextHandler.java:265)

at org.eclipse.jetty.webapp.WebAppContext.startContext(WebAppContext.java:1250)

at org.eclipse.jetty.server.handler.ContextHandler.doStart(ContextHandler.java:706)

at org.eclipse.jetty.webapp.WebAppContext.doStart(WebAppContext.java:492)

at org.eclipse.jetty.util.component.AbstractLifeCycle.start(AbstractLifeCycle.java:64)

at org.eclipse.jetty.server.handler.HandlerWrapper.doStart(HandlerWrapper.java:95)

at org.eclipse.jetty.server.Server.doStart(Server.java:277)

at org.eclipse.jetty.util.component.AbstractLifeCycle.start(AbstractLifeCycle.java:64)

at com.jfinal.server.JettyServer.doStart(JettyServer.java:133)

at com.jfinal.server.JettyServer.start(JettyServer.java:70)

at com.jfinal.core.JFinal.start(JFinal.java:162)

at config.MyConfig.main(MyConfig.java:62)

2018-04-09 18:23:32.368:WARN:oejuc.AbstractLifeCycle:FAILED o.e.j.w.WebAppContext{/,file:/E:/WorkSpace/TestJfinal/WebRoot/}: java.lang.IllegalAccessError: class sun.reflect.GeneratedConstructorAccessor7 cannot access its superclass sun.reflect.ConstructorAccessorImpl