连接数据库失败，无法运行

错误信息：

2018-02-11 18:01:27.162:WARN:oejuc.AbstractLifeCycle:FAILED jfinal: java.lang.IllegalAccessError: class sun.reflect.GeneratedConstructorAccessor4 cannot access its superclass sun.reflect.ConstructorAccessorImpl

java.lang.IllegalAccessError: class sun.reflect.GeneratedConstructorAccessor4 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:411)

at com.mysql.jdbc.ResultSetImpl.getInstance(ResultSetImpl.java:383)

at com.mysql.jdbc.MysqlIO.buildResultSetWithRows(MysqlIO.java:3140)

at com.mysql.jdbc.MysqlIO.getResultSet(MysqlIO.java:493)

at com.mysql.jdbc.MysqlIO.readResultsForQueryOrUpdate(MysqlIO.java:3118)

at com.mysql.jdbc.MysqlIO.readAllResults(MysqlIO.java:2288)

at com.mysql.jdbc.MysqlIO.sqlQueryDirect(MysqlIO.java:2709)

at com.mysql.jdbc.ConnectionImpl.execSQL(ConnectionImpl.java:2728)

at com.mysql.jdbc.ConnectionImpl.execSQL(ConnectionImpl.java:2678)

at com.mysql.jdbc.StatementImpl.executeQuery(StatementImpl.java:1612)

at com.mchange.v2.c3p0.impl.NewProxyStatement.executeQuery(NewProxyStatement.java:177)

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.main(JFinal.java:189)

2018-02-11 18:01:27.163:WARN:oejuc.AbstractLifeCycle:FAILED o.e.j.w.WebAppContext{/,file:/D:/javaee/hotel_jfinal/WebRoot/}: java.lang.IllegalAccessError: class sun.reflect.GeneratedConstructorAccessor4 cannot access its superclass sun.reflect.ConstructorAccessorImpl