刚开始使用nutz，连接数据库的时候老是报 For object [dataSource] - type:[null]错误，哪位大神给指导一下呀

代码如下：
2015-11-27 16:04:06,407 [http-8080-1] DEBUG org.nutz.ioc.loader.map.MapLoader - Loading define for name=dataSource
2015-11-27 16:04:06,410 [http-8080-1] ERROR org.nutz.mvc.impl.processor.FailProcessor - Catch handle error
org.nutz.ioc.IocException: For object [dataSource] - type:[null]
at org.nutz.ioc.impl.NutIoc.get(NutIoc.java:186)
at org.nutz.ioc.val.ReferValue.get(ReferValue.java:24)
at org.nutz.ioc.impl.ObjectMakerImpl.make(ObjectMakerImpl.java:66)
at org.nutz.ioc.impl.NutIoc.get(NutIoc.java:182)
at org.nutz.ioc.val.ReferValue.get(ReferValue.java:24)
at org.nutz.ioc.weaver.FieldInjector.inject(FieldInjector.java:23)
at org.nutz.ioc.weaver.DefaultWeaver.fill(DefaultWeaver.java:56)
at org.nutz.ioc.impl.ObjectMakerImpl.make(ObjectMakerImpl.java:95)
at org.nutz.ioc.impl.NutIoc.get(NutIoc.java:182)
at org.nutz.ioc.val.ReferValue.get(ReferValue.java:24)
at org.nutz.ioc.weaver.FieldInjector.inject(FieldInjector.java:23)
at org.nutz.ioc.weaver.DefaultWeaver.fill(DefaultWeaver.java:56)
at org.nutz.ioc.impl.ObjectMakerImpl.make(ObjectMakerImpl.java:95)
at org.nutz.ioc.impl.NutIoc.get(NutIoc.java:182)
at org.nutz.mvc.impl.processor.ModuleProcessor.process(ModuleProcessor.java:70)
at org.nutz.mvc.impl.processor.AbstractProcessor.doNext(AbstractProcessor.java:44)
at org.nutz.mvc.impl.processor.EncodingProcessor.process(EncodingProcessor.java:27)
at org.nutz.mvc.impl.processor.AbstractProcessor.doNext(AbstractProcessor.java:44)
at org.nutz.mvc.impl.processor.UpdateRequestAttributesProcessor.process(UpdateRequestAttributesProcessor.java:15)
at org.nutz.mvc.impl.NutActionChain.doChain(NutActionChain.java:36)
at org.nutz.mvc.impl.ActionInvoker.invoke(ActionInvoker.java:66)
at org.nutz.mvc.ActionHandler.handle(ActionHandler.java:30)
at org.nutz.mvc.NutServlet.service(NutServlet.java:56)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:717)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:290)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:233)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:191)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:128)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:102)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:109)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:293)
at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:849)
at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.java:583)
at org.apache.tomcat.util.net.JIoEndpoint$Worker.run(JIoEndpoint.java:454)
at java.lang.Thread.run(Thread.java:722)
Caused by: org.nutz.ioc.ObjectLoadException: Wrong type name: 'com.alibaba.druid.pool.DruidDataSource'
at org.nutz.ioc.IocLoading.E(IocLoading.java:38)
at org.nutz.ioc.IocLoading.map2iobj(IocLoading.java:64)
at org.nutz.ioc.loader.map.MapLoader.load(MapLoader.java:86)
at org.nutz.ioc.loader.cached.CachedIocLoaderImpl.load(CachedIocLoaderImpl.java:47)
at org.nutz.ioc.impl.NutIoc.get(NutIoc.java:164)
... 35 more