生凉拌西芹的做法大全:JSP报错 HTTP Status 500

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
examples.ShowSource.doEndTag(ShowSource.java:38)
org.apache.jsp.source_jsp._jspService(source_jsp.java:64)
org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:97)
javax.servlet.http.HttpServlet.service(HttpServlet.java:802)

note The full stack trace of the root cause is available in the Apache Tomcat/5.5.17 logs.

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Apache Tomcat/5.5.17
http://zhidao.baidu.com/question/5333148.html
……
5 .好了，重启动Tomcat，启动浏览器，输入http://localhost:8080/myapp/Test 如果看到输出This is a servlet test.就说明编写的servlet成功了。

注意：修改了web.xml以及新加了class，都要重启Tomcat

第四步：建立自己的Bean
……
救救我吧，我到这儿出错了
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

半月了，就是过不去，一步也没有差啊，天啊，放过我吧……!@

各位大哥大姐，是不是还是配置问题啊？
我用apache tomcat 5.5.17