新年好：对于java.lang.IllegalArgumentException: Can't convert argument: null

新年好：关于java.lang.IllegalArgumentException: Can't convert argument: null
Tomcat6.0+myeclipse,   普通servlet，出现如下错误，高手给侃侃
java.lang.IllegalArgumentException:   Can 't   convert   argument:   null
at   org.apache.tomcat.util.IntrospectionUtils.convert(IntrospectionUtils.java:976)
at   org.apache.tomcat.util.digester.CallMethodRule.end(CallMethodRule.java:523)
at   org.apache.tomcat.util.digester.Rule.end(Rule.java:229)

------解决方案--------------------
Can 't convert argument--转化错误吧，具体情况LZ将代码发下