Jfinal链接数据库出错? 400 请求报错

一启动服务器就出现:描述如下:
严重: Exception starting filter jfinal java.lang.NoClassDefFoundError: com/mchange/v2/c3p0/ComboPooledDataSource at com.jfinal.plugin.c3p0.C3p0Plugin.start(C3p0Plugin.java:110) at com.jfinal.core.Config.startPlugins(Config.java:78) at com.jfinal.core.Config.configJFinal(Config.java:48) at com.jfinal.core.JFinal.init(JFinal.java:65) at com.jfinal.core.JFinalFilter.init(JFinalFilter.java:48) at org.apache.catalina.core.ApplicationFilterConfig.getFilter(ApplicationFilterConfig.java:275) at org.apache.catalina.core.ApplicationFilterConfig.setFilterDef(ApplicationFilterConfig.java:397) at org.apache.catalina.core.ApplicationFilterConfig.<init>(ApplicationFilterConfig.java:108) at org.apache.catalina.core.StandardContext.filterStart(StandardContext.java:3693) at org.apache.catalina.core.StandardContext.start(StandardContext.java:4340) at org.apache.catalina.core.ContainerBase.addChildInternal(ContainerBase.java:791) at org.apache.catalina.core.ContainerBase.addChild(ContainerBase.java:771) at org.apache.catalina.core.StandardHost.addChild(StandardHost.java:525) at org.apache.catalina.startup.HostConfig.deployDirectory(HostConfig.java:920) at org.apache.catalina.startup.HostConfig.deployDirectories(HostConfig.java:883) at org.apache.catalina.startup.HostConfig.deployApps(HostConfig.java:492) at org.apache.catalina.startup.HostConfig.start(HostConfig.java:1138) at org.apache.catalina.startup.HostConfig.lifecycleEvent(HostConfig.java:311) at org.apache.catalina.util.LifecycleSupport.fireLifecycleEvent(LifecycleSupport.java:117) at org.apache.catalina.core.ContainerBase.start(ContainerBase.java:1053) at org.apache.catalina.core.StandardHost.start(StandardHost.java:719) at org.apache.catalina.core.ContainerBase.start(ContainerBase.java:1045) at org.apache.catalina.core.StandardEngine.start(StandardEngine.java:443) at org.apache.catalina.core.StandardService.start(StandardService.java:516) at org.apache.catalina.core.StandardServer.start(StandardServer.java:710) at org.apache.catalina.startup.Catalina.start(Catalina.java:566) at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25) at java.lang.reflect.Method.invoke(Method.java:597) at org.apache.catalina.startup.Bootstrap.start(Bootstrap.java:288) at org.apache.catalina.startup.Bootstrap.main(Bootstrap.java:413) Caused by: java.lang.ClassNotFoundException: com.mchange.v2.c3p0.ComboPooledDataSource at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1358) at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1204) at java.lang.ClassLoader.loadClassInternal(ClassLoader.java:320) ... 32 more 2013-1-16 21:00:17 org.apache.catalina.core.StandardContext start 严重: Error filterStart