无锡房价降了吗:jsp调试中的错误,请高手指点
来源:百度文库 编辑:查人人中国名人网 时间:2024/10/01 10:50:22
下面是错误提示:
HTTP Status 500 -
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type Exception report
message
description The server encountered an internal error () that prevented it from fulfilling this request.
exception
java.lang.NullPointerException
kqsw.Login.doPost(Login.java:21)
javax.servlet.http.HttpServlet.service(HttpServlet.java:709)
javax.servlet.http.HttpServlet.service(HttpServlet.java:802)
note The full stack trace of the root cause is available in the Apache Tomcat/5.0.30 logs.
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Apache Tomcat/5.0.30
请高手指点。。。。。
HTTP Status 500 -
--------------------------------------------------------------------------------
type Exception report
message
description The server encountered an internal error () that prevented it from fulfilling this request.
exception
java.lang.NullPointerException
kqsw.Login.doPost(Login.java:21)
javax.servlet.http.HttpServlet.service(HttpServlet.java:709)
javax.servlet.http.HttpServlet.service(HttpServlet.java:802)
note The full stack trace of the root cause is available in the Apache Tomcat/5.0.30 logs.
--------------------------------------------------------------------------------
Apache Tomcat/5.0.30
请高手指点。。。。。
NullPointerException 调用了一个没有初始化的对象,也就是说想对一个空值进行操作,比如想取得一个参数,而你又没有传递进来。。。
空指针。
你的java中引用了没有赋值的变量