0001----问个学jsp都能懂的问题！（网上图书管理系统的问题）

Question

HTTP状态500 - --------------------------------------------------------------------------------type 异 常 报 告信 息 描 述 服务器遇到内部错误，无法满足这个访问请求异 常 org.apache.jasper.JasperException
org.apache.jasper.servlet.JspServletWrapper.handleJspException(JspServletWrapper.java:512)
org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:377)
org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:314)
org.apache.jasper.servlet.JspServlet.service(JspServlet.java:264)
javax.servlet.http.HttpServlet.service(HttpServlet.java:802)
起 因 org.apache.jasper.JasperException
org.apache.jasper.servlet.JspServletWrapper.handleJspException(JspServletWrapper.java:512)
org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:395)
org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:314)
org.apache.jasper.servlet.JspServlet.service(JspServlet.java:264)
javax.servlet.http.HttpServlet.service(HttpServlet.java:802)
org.apache.jasper.runtime.JspRuntimeLibrary.include(JspRuntimeLibrary.java:966)
org.apache.jsp.index_jsp._jspService(index_jsp.java:91)
org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:97)
javax.servlet.http.HttpServlet.service(HttpServlet.java:802)
org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:334)
org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:314)
org.apache.jasper.servlet.JspServlet.service(JspServlet.java:264)
javax.servlet.http.HttpServlet.service(HttpServlet.java:802)
起 因 java.lang.NullPointerException
org.apache.jsp.left_jsp._jspService(left_jsp.java:182)
org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:97)
javax.servlet.http.HttpServlet.service(HttpServlet.java:802)
org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:334)
org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:314)
org.apache.jasper.servlet.JspServlet.service(JspServlet.java:264)
javax.servlet.http.HttpServlet.service(HttpServlet.java:802)
org.apache.jasper.runtime.JspRuntimeLibrary.include(JspRuntimeLibrary.java:966)
org.apache.jsp.index_jsp._jspService(index_jsp.java:91)
org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:97)
javax.servlet.http.HttpServlet.service(HttpServlet.java:802)
org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:334)
org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:314)
org.apache.jasper.servlet.JspServlet.service(JspServlet.java:264)
javax.servlet.http.HttpServlet.service(HttpServlet.java:802)
注 意 完整的起因在Apache Tomcat/5.5.20里。
--------------------------------------------------------------------------------Apache Tomcat/5.5.20
Jaxmao Project

Answer 1

空指针异常.java.lang.NullPointerException 肯定在JSP页面里

Answer 2

org.apache.jsp.left_jsp._jspService(left_jsp.java:182) 错误在这里
left.jsp编译后的java文件的182行，
你找一下work目录下的编译后的java文件，找到182行，看看对应jsp的代码是怎么样的就知道了

Answer 3

tomcat的work工作目錄下面找到org.apache.jsp.left_jsp._jspService(left_jsp.java:182) 
包空指針異常，182行左右會給你提示，然后修正left.jsp文件重新運行編譯；

Answer 4

Jaxmao Project
HTTP状态500 - --------------------------------------------------------------------------------type 异 常 报 告信 息 描 述 服务器遇到内部错误，无法满足这个访问请求异 常 org.apache.jasper.JasperException: Exception in JSP: /index.jsp:2724:  <table width="100%" height="330"  border="0" cellpadding="0" cellspacing="0">
25:         <tr>
26:           <td width="26%" valign="top">
27:   <jsp:include page="left.jsp"/> 
28:  </td>
29:           <td width="5" valign="top" background="Images/Cen_separate.gif"></td>
30:           <td width="73%" valign="top"><table width="100%" height="272"  border="0" cellpadding="0" cellspacing="0">
Stacktrace:
org.apache.jasper.servlet.JspServletWrapper.handleJspException(JspServletWrapper.java:506)
org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:377)
org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:314)
org.apache.jasper.servlet.JspServlet.service(JspServlet.java:264)
javax.servlet.http.HttpServlet.service(HttpServlet.java:802)
起 因 org.apache.jasper.JasperException: Exception in JSP: /left.jsp:110107:               <td width="14%">&nbsp;</td>
108:               <td width="86%" height="100" valign="top" class="tableBorder_B">
109:    <marquee direction="up" scrollamount="1" scrolldelay="1" height="100" onMouseMove="this.stop()" onMouseOut="this.start()">
110:    <%while(rs_bbs.next()){%>
111:    <table width="100%" height="21"  border="0" cellpadding="0" cellspacing="0">
112:                 <tr>
113:                   <td><%=chStr.convertStr(rs_bbs.getString("content"))%></td>
Stacktrace:
org.apache.jasper.servlet.JspServletWrapper.handleJspException(JspServletWrapper.java:506)
org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:395)
org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:314)
org.apache.jasper.servlet.JspServlet.service(JspServlet.java:264)
javax.servlet.http.HttpServlet.service(HttpServlet.java:802)
org.apache.jasper.runtime.JspRuntimeLibrary.include(JspRuntimeLibrary.java:966)
org.apache.jsp.index_jsp._jspService(index_jsp.java:91)
org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:97)
javax.servlet.http.HttpServlet.service(HttpServlet.java:802)
org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:334)
org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:314)
org.apache.jasper.servlet.JspServlet.service(JspServlet.java:264)
javax.servlet.http.HttpServlet.service(HttpServlet.java:802)
起 因 java.lang.NullPointerException
org.apache.jsp.left_jsp._jspService(left_jsp.java:182)
org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:97)
javax.servlet.http.HttpServlet.service(HttpServlet.java:802)
org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:334)
org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:314)
org.apache.jasper.servlet.JspServlet.service(JspServlet.java:264)
javax.servlet.http.HttpServlet.service(HttpServlet.java:802)
org.apache.jasper.runtime.JspRuntimeLibrary.include(JspRuntimeLibrary.java:966)
org.apache.jsp.index_jsp._jspService(index_jsp.java:91)
org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:97)
javax.servlet.http.HttpServlet.service(HttpServlet.java:802)
org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:334)
org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:314)
org.apache.jasper.servlet.JspServlet.service(JspServlet.java:264)
javax.servlet.http.HttpServlet.service(HttpServlet.java:802)
注 意 完整的起因在Apache Tomcat/5.5.20里。
--------------------------------------------------------------------------------Apache Tomcat/5.5.20
Jaxmao Project
----------------------------现在又是这个效果了？ 怎么起的 谢谢大家 继续帮忙

Answer 5

rs_bbs 没有实例化吧，
是空指针null

Answer 6

怀疑：
数据库里面得content字段是不是NULL啊，
然后getString("content"))取出来是NULL。
然后convertStr函数里面处理NULL出错了。

Answer 7

我的错误是:
type 异 常 报 告信 息 描 述 服务器遇到内部错误，无法满足这个访问请求异 常 org.apache.jasper.JasperException: Unable to load class for JSP
org.apache.jasper.servlet.JspServletWrapper.handleJspException(JspServletWrapper.java:512)
org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:377)
org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:314)
org.apache.jasper.servlet.JspServlet.service(JspServlet.java:264)
javax.servlet.http.HttpServlet.service(HttpServlet.java:802)
org.apache.struts2.dispatcher.FilterDispatcher.doFilter(FilterDispatcher.java:413)
起 因 org.apache.jasper.JasperException: Unable to load class for JSP
org.apache.jasper.JspCompilationContext.load(JspCompilationContext.java:598)
org.apache.jasper.servlet.JspServletWrapper.getServlet(JspServletWrapper.java:147)
org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:317)
org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:314)
org.apache.jasper.servlet.JspServlet.service(JspServlet.java:264)
javax.servlet.http.HttpServlet.service(HttpServlet.java:802)
org.apache.struts2.dispatcher.FilterDispatcher.doFilter(FilterDispatcher.java:413)
起 因 java.lang.ClassNotFoundException: org.apache.jsp.url_jsp
java.net.URLClassLoader$1.run(Unknown Source)
java.security.AccessController.doPrivileged(Native Method)
java.net.URLClassLoader.findClass(Unknown Source)
org.apache.jasper.servlet.JasperLoader.loadClass(JasperLoader.java:133)
org.apache.jasper.servlet.JasperLoader.loadClass(JasperLoader.java:65)
org.apache.jasper.JspCompilationContext.load(JspCompilationContext.java:596)
org.apache.jasper.servlet.JspServletWrapper.getServlet(JspServletWrapper.java:147)
org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:317)
org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:314)
org.apache.jasper.servlet.JspServlet.service(JspServlet.java:264)
javax.servlet.http.HttpServlet.service(HttpServlet.java:802)
org.apache.struts2.dispatcher.FilterDispatcher.doFilter(FilterDispatcher.java:413)
注 意 完整的起因在Apache Tomcat/5.5.20里。
原程序为:
<%@ page contentType="text/html;charset=UTF-8" %>
<%@ taglib prefix="s" uri="/struts-tags" %><html>
<head>
<title> Page of Include </title>
</head>
<body>
<h3> Iterator page </h3>
<s:include value="/iterator.jsp"></s:include>
<h3> I18n page </h3>
<s:include value="/i18n.jsp" />
<h3> Condition page </h3>
<s:include value="/condition.jsp">
<s:param name = "name">Max</s:param>
</s:include>
</body>
</html>
又是怎么一回事? 到底是服务器没装好还是代码的问题???