Question

用JSP开发一网站用到TOMCAT和SQL sever2000，JDK 都已经安装！环境变量已经配置。但运行不出来。

环境变量：
JAVA_HOME：C:\Program Files\Java\jdk1.5.0_10
PATH:%JAVA_HOME%\bin;
CLASSPATH：.;C:\Program Files\Java\jdk1.5.0_10\lib\dt.jar;C:\Program Files\Java\jdk1.5.0_10\lib\tools.jar;C:\Program Files\Apache Software Foundation\Tomcat 5.5\common\lib\servlet-api.jar;C:\Program Files\Apache Software Foundation\Tomcat 5.5\common\lib\jsp-api.jar;C:\Program Files\Apache Software Foundation\Tomcat 5.5\webapps\ROOT\WEB-INF\lib\mssqlserver.jar;C:\Program Files\Apache Software Foundation\Tomcat 5.5\webapps\ROOT\WEB-INF\lib\msutil.jar;C:\Program Files\Apache Software Foundation\Tomcat 5.5\webapps\ROOT\WEB-INF\lib\msbase.jar;C:\Program Files\Microsoft SQL Server 2000 Driver for JDBC\lib\msbase.jar;C:\Program Files\Microsoft SQL Server 2000 Driver for JDBC\lib\mssqlserver.jar;C:\Program Files\Microsoft SQL Server 2000 Driver for JDBC\lib\msutil.jar;C:\Program Files\Java\jdk1.5.0_10\jre\lib\mssqlserver.jar;C:\Program Files\Java\jdk1.5.0_10\jre\lib\msutil.jar;C:\Program Files\Java\jdk1.5.0_10\jre\lib\msbase.jar;
TOMCAT 配置：
CATALINA_BASE和CATALINA_HOME和CATALINA_HOME配置都是:C:\Program Files\Apache Software Foundation\Tomcat 5.5
.Java文件可成功运行
在webapps\myapp创建*.jsp文件运行成功。
可就是网站运行不了，在网上看还有改什么web.xml文件啊？用吗？
错误提示
description The server encountered an internal error () that prevented it from fulfilling this request.

exception

org.apache.jasper.JasperException
org.apache.jasper.servlet.JspServletWrapper.handleJspException(JspServletWrapper.java:460)
org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:373)
org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:329)
org.apache.jasper.servlet.JspServlet.service(JspServlet.java:265)
javax.servlet.http.HttpServlet.service(HttpServlet.java:729)
org.apache.jasper.runtime.JspRuntimeLibrary.include(JspRuntimeLibrary.java:965)
org.apache.jsp.index_jsp._jspService(index_jsp.java:91)
org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:98)
javax.servlet.http.HttpServlet.service(HttpServlet.java:729)
org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:331)
org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:329)
org.apache.jasper.servlet.JspServlet.service(JspServlet.java:265)
javax.servlet.http.HttpServlet.service(HttpServlet.java:729)

root cause

java.lang.NullPointerException
org.apache.jsp.left_jsp._jspService(left_jsp.java:182)
org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:98)
javax.servlet.http.HttpServlet.service
还有呢只是拷部了了 字数又限制

Answer 1

不是你的配置有问题你的安装是对的，应该是你的程序代码的问题，仔细查看下自己的代码，打断点看看,看下哪个变量为空值

Answer 2

可能是程序代码的问题，也可能是.xml文件没有配置好，着重考虑一下数据库的配置，建议你把代码贴出来

Answer 3

很明显。这是服务器内部错误。你代码在运行时出现了空指针异常。检查一下吧。小问题