具体信息:
Caused by: java.lang.NoClassDefFoundError: Lorg/apache/commons/logging/Log;
at java.lang.Class.getDeclaredFields0(Native Method)
at java.lang.Class.privateGetDeclaredFields(Class.java:2583)
at java.lang.Class.getDeclaredFields(Class.java:1916)
at org.apache.catalina.util.Introspection.getDeclaredFields(Introspection.java:110)
at org.apache.catalina.startup.WebAnnotationSet.loadFieldsAnnotation(WebAnnotationSet.java:269)
at org.apache.catalina.startup.WebAnnotationSet.loadApplicationListenerAnnotations(WebAnnotationSet.java:89)
at org.apache.catalina.startup.WebAnnotationSet.loadApplicationAnnotations(WebAnnotationSet.java:67)
at org.apache.catalina.startup.ContextConfig.applicationAnnotationsConfig(ContextConfig.java:328)
at org.apache.catalina.startup.ContextConfig.configureStart(ContextConfig.java:772)
at org.apache.catalina.startup.ContextConfig.lifecycleEvent(ContextConfig.java:299)
at org.apache.catalina.util.LifecycleBase.fireLifecycleEvent(LifecycleBase.java:94)
at org.apache.catalina.core.StandardContext.startInternal(StandardContext.java:5154)
at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:150)
... 6 more
Caused by: java.lang.ClassNotFoundException: org.apache.commons.logging.Log
at org.apache.catalina.loader.WebappClassLoaderBase.loadClass(WebappClassLoaderBase.java:1328)
at org.apache.catalina.loader.WebappClassLoaderBase.loadClass(WebappClassLoaderBase.java:1156)
... 19 more
解决方法:
https://www.cnblogs.com/yuchangwei/archive/2012/12/13/2816756.html
Note: This element neither has attached source nor attached Javadoc and hence no Javadoc could be found.
在用Eclipse编写程序时,发现把鼠标放到类名上时出现标题的提示
解决方法:
右击项目,选择 properties –> Java Build Path –> Libraries,如图
以jxl.jar为例,单击jax.jar左边的三角符号,出现
从上面看Javadoc location:(None),说明没有导入帮助文档,双击Javadoc location:(None)后出现
这里在输入框中可以输入文档的网络URL地址或者本地的doc帮助文档,这里我是选择本地的,单击Browse按钮,找到帮助文档,确定
从上面看已经成功导入了帮助文档。在编译器中也可以显示出解释信息了