org.apache.jasper.JasperException: java.lang.NullPointerException

阿c 2012-06-18 11:48:37

org.apache.jasper.JasperException: java.lang.NullPointerException
org.apache.jasper.servlet.JspServletWrapper.handleJspException(JspServletWrapper.java:538)
org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:370)
org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:313)
org.apache.jasper.servlet.JspServlet.service(JspServlet.java:260)
javax.servlet.http.HttpServlet.service(HttpServlet.java:717)

代码，是个空页面，想要测试一下，但是出错了
<%@ page language="java" contentType="text/html; charset=gbk"
pageEncoding="gbk"%>
<%@ page import = "java.sql.*" %>

<%
Class.forName("com.mysql.jdbc.Driver");
String url = "jdbc:mysql://localhost:3306/bbs?" + "user=root&password=123";
Connection conn = DriverManager.getConnection(url);
%>

<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=gbk">
<title>Insert title here</title>
</head>
<body>

</body>
<%
conn.close();
%>

...全文

5398 9 打赏收藏转发到动态举报

写回复

用AI写文章

9 条回复

切换为时间正序

请发表友善的回复…

发表回复

阿c 2012-06-19

打赏
举报

谢谢大家，已经解决了，我的解决方法：
1）：把referenced libraries里面和tomcat lib下面相同的jar包删除，导入db驱动包
2）：把tomcat的contex.xml 里加入 <loader delegate = "true" /> 加的时候不要忘了先备份。

谢谢大家了，高兴！！！哈哈哈

nmyangym 2012-06-19

打赏
举报

at org.apache.jsp.ShowArticleTree_jsp._jspInit(ShowArticleTree_jsp.java:23)
到%TOMCAT_HOME%/work/"工程目录"/org/apache/jsp下看看那个ShowArticleTree_jsp.java,提示_jspInit这个方法里出现的空指针异常。

阿c 2012-06-19

打赏
举报

还是一样的，我把错误信息全贴上你看看
严重: Servlet.service() for servlet jsp threw exception
java.lang.NullPointerException
at org.apache.jsp.ShowArticleTree_jsp._jspInit(ShowArticleTree_jsp.java:23)
at org.apache.jasper.runtime.HttpJspBase.init(HttpJspBase.java:52)
at org.apache.jasper.servlet.JspServletWrapper.getServlet(JspServletWrapper.java:164)
at org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:340)
at org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:313)
at org.apache.jasper.servlet.JspServlet.service(JspServlet.java:260)
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:127)
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:859)
at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.java:602)
at org.apache.tomcat.util.net.JIoEndpoint$Worker.run(JIoEndpoint.java:489)
at java.lang.Thread.run(Thread.java:619)

[Quote=引用 5 楼的回复:]

HTML code

Connection conn = DriverManager.getConnection("jdbc:mysql://localhost:3306/bbs", "root","123");

该成这样试试
[/Quote]

NoTargetException 2012-06-19

打赏
举报



  Connection conn = DriverManager.getConnection("jdbc:mysql://localhost:3306/bbs", "root","123");

该成这样试试

阿c 2012-06-19

打赏
举报

需要引入那些包？tomcat下的servlet-api.jar; mysql-connector-java.jar;都引入了，其他的我也试过，还是出现同样的错误，困扰我两天了。

[Quote=引用 1 楼的回复:]

我新手，你看你是否在项目中引入相应的包。
nullPonintException，或许是你没有引入相应的包，或者就是你调用出问题了。你用的编译器没有提示吗？
[/Quote]