新手看不太懂，求大神帮助！可以确定是Druid和ActiveRecordPlugin的问题，注释掉这块代码就不报错了。
错误内容：
2017-12-21 18:34:42.142:WARN:oejuc.AbstractLifeCycle:FAILED jfinal: java.lang.IllegalAccessError: class sun.reflect.GeneratedConstructorAccessor1 cannot access its superclass sun.reflect.ConstructorAccessorImpl
java.lang.IllegalAccessError: class sun.reflect.GeneratedConstructorAccessor1 cannot access its superclass sun.reflect.ConstructorAccessorImpl
at sun.misc.Unsafe.defineClass(Native Method)
at sun.reflect.ClassDefiner.defineClass(ClassDefiner.java:63)
at sun.reflect.MethodAccessorGenerator$1.run(MethodAccessorGenerator.java:399)
at sun.reflect.MethodAccessorGenerator$1.run(MethodAccessorGenerator.java:394)
at java.security.AccessController.doPrivileged(Native Method)
at sun.reflect.MethodAccessorGenerator.generate(MethodAccessorGenerator.java:393)
at sun.reflect.MethodAccessorGenerator.generateConstructor(MethodAccessorGenerator.java:92)
at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:55)
at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
at java.lang.reflect.Constructor.newInstance(Constructor.java:423)
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.mysql.jdbc.ConnectionImpl.getTransactionIsolation(ConnectionImpl.java:3008)
at com.alibaba.druid.pool.DruidConnectionHolder.<init>(DruidConnectionHolder.java:145)
at com.alibaba.druid.pool.DruidConnectionHolder.<init>(DruidConnectionHolder.java:83)
at com.alibaba.druid.pool.DruidDataSource.init(DruidDataSource.java:735)
at com.alibaba.druid.pool.DruidDataSource.getConnection(DruidDataSource.java:1060)
at com.alibaba.druid.pool.DruidDataSource.getConnection(DruidDataSource.java:1056)
at com.alibaba.druid.pool.DruidDataSource.getConnection(DruidDataSource.java:104)
at com.jfinal.plugin.activerecord.TableBuilder.build(TableBuilder.java:43)
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 com.blog.BlogConfig.main(BlogConfig.java:19)
