求助SSH整合异常：java.lang.NullPointerException

Question

2009-11-18 20:51:10 org.apache.catalina.core.ApplicationDispatcher invoke
严重: Servlet.service() for servlet jsp threw exception
java.lang.NullPointerException
at org.apache.struts2.components.table.WebTable.setSortOrder(WebTable.java:268)
at org.apache.struts2.views.jsp.ui.table.WebTableTag.populateParams(WebTableTag.java:53)
at org.apache.struts2.views.jsp.ComponentTagSupport.doStartTag(ComponentTagSupport.java:53)
at org.apache.jsp.update_jsp._jspx_meth_s_005ftable_005f0(update_jsp.java:150)
at org.apache.jsp.update_jsp._jspx_meth_s_005fform_005f0(update_jsp.java:121)
at org.apache.jsp.update_jsp._jspService(update_jsp.java:82)
at org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:70)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:803)
at org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:384)
at org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:320)
at org.apache.jasper.servlet.JspServlet.service(JspServlet.java:266)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:803)
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.ApplicationDispatcher.invoke(ApplicationDispatcher.java:687)
at org.apache.catalina.core.ApplicationDispatcher.processRequest(ApplicationDispatcher.java:469)
at org.apache.catalina.core.ApplicationDispatcher.doForward(ApplicationDispatcher.java:403)
at org.apache.catalina.core.ApplicationDispatcher.forward(ApplicationDispatcher.java:301)
at org.apache.struts2.dispatcher.ServletDispatcherResult.doExecute(ServletDispatcherResult.java:139)
at org.apache.struts2.dispatcher.StrutsResultSupport.execute(StrutsResultSupport.java:178)
at com.opensymphony.xwork2.DefaultActionInvocation.executeResult(DefaultActionInvocation.java:348)
at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:253)
。
         。
         。
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:228)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:175)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:128)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:104)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:109)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:216)
at org.apache.coyote.http11.Http11AprProcessor.process(Http11AprProcessor.java:866)
at org.apache.coyote.http11.Http11AprProtocol$Http11ConnectionHandler.process(Http11AprProtocol.java:716)
at org.apache.tomcat.util.net.AprEndpoint$Worker.run(AprEndpoint.java:1498)
at java.lang.Thread.run(Thread.java:619)struts.xml如下：
<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE struts PUBLIC
    "-//Apache Software Foundation//DTD Struts Configuration 2.0//EN"
    "http://struts.apache.org/dtds/struts-2.0.dtd"><struts>
<package name="user" extends="struts-default">

<action name="saveUser" class="saveUserAction">
<result name="success" type="redirect">listUser.action</result>
<result name="input">/save.jsp</result>
</action>

<action name="listUser" class="listUserAction">
<result>/list.jsp</result>
</action>

<action name="deleteUser" class="removeUserAction">
<result name="success" type="redirect">listUser.action</result>
</action>

<action name="updatePUser" class="updatePUserAction">
<result name="success" >/update.jsp</result>
</action>

<action name="updateUser" class="updateUserAction">
<result name="success" type="redirect">listUser.action</result>
<result name="input">/update.jsp</result>
</action>

<action name="generateExcel" class="generateExcelAction">
<result name="success" type="stream">
<param name="contentType">application/vnd.ms-excel</param>
<param name="contentDisposition">filename="AllUsers.xls"</param>
<param name="inputName">downloadFile</param>
</result>
</action>

</package>
</struts>applicationContext.xml如下：
<?xml version="1.0" encoding="UTF-8"?>
<beans
xmlns="http://www.springframework.org/schema/beans"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-2.0.xsd"><bean id="dataSource" class="org.apache.commons.dbcp.BasicDataSource" destroy-method="close"> <!--  destory-method="close" 用完后把连接放回连接池--> 
<property name="driverClassName" value="com.mysql.jdbc.Driver"></property>
<property name="url" value="jdbc:mysql://localhost:3306/mytest"></property>
<property name="username" value="root"></property>
<property name="password" value="root"></property>
<property name="maxActive" value="100"></property>
<property name="maxIdle" value="30"></property>
<property name="maxWait" value="500"></property>
<property name="defaultAutoCommit" value="true"></property>
</bean><bean id="sessionFactory" class="org.springframework.orm.hibernate3.LocalSessionFactoryBean">
<property name="dataSource" ref="dataSource"></property>
<property name="hibernateProperties">
<props>
<prop key="hibernate.dialect">org.hibernate.dialect.MySQLDialect</prop>
<prop key="hibernate.show_sql">true</prop>
</props>
</property>
<property name="mappingResources">
<list>
<value>com/test/bean/User.hbm.xml</value>
</list>
</property>
</bean><bean id="userDao" class="com.test.dao.impl.UserDAOImpl" scope="singleton">
<property name="sessionFactory">
<ref bean="sessionFactory"/>
</property>
</bean><bean id="userService" class="com.test.service.impl.UserServiceImpl">
<property name="userDao" ref="userDao"></property>
</bean><bean id="saveUserAction" class="com.test.action.user.SaveUserAction" scope="prototype">
<property name="service" ref="userService"></property>
</bean><bean id="listUserAction" class="com.test.action.user.ListUserAction" scope="prototype">
<property name="service" ref="userService"></property>
</bean><bean id="removeUserAction" class="com.test.action.user.RemoveUserAction" scope="prototype">
<property name="service" ref="userService"></property>
</bean><bean id="updatePUserAction" class="com.test.action.user.UpdatePUserAction" scope="prototype">
<property name="service" ref="userService"></property>
</bean><bean id="updateUserAction" class="com.test.action.user.UpdateUserAction" scope="prototype">
<property name="service" ref="userService"></property>
</bean><bean id="generateExcelAction" class="com.test.action.user.GenerateExcelAction" scope="singleton">
<property name="service" ref="userService"></property>
</bean></beans>

Answer 1

上works文件夹下看源码就知道错误所在，这样的问题只是这样看没人有耐心去回答。

Answer 2

update.jsp
操作了一个空的对象··

Answer 3

在struts1里面遇到过这个问题，最后在struts-config.xml里加上
<message-resources parameter="xxx.struts.ApplicationResources"/>就ok了
在sturts2里没遇到过，你试试在struts。properties里加上
struts.custom.i18n.resources=default这句看看

Answer 4

回复1楼：
  works下的update_jsp.java文件看不懂，比如提示的错误为：
at org.apache.jsp.update_jsp._jspx_meth_s_005ftable_005f0(update_jsp.java:150) 
 而update_jsp.java的第150行文件为：
    org.apache.struts2.views.jsp.ui.table.WebTableTag _jspx_th_s_005ftable_005f0 = (org.apache.struts2.views.jsp.ui.table.WebTableTag) _005fjspx_005ftagPool_005fs_005ftable.get(org.apache.struts2.views.jsp.ui.table.WebTableTag.class);
    _jspx_th_s_005ftable_005f0.setPageContext(_jspx_page_context);
    _jspx_th_s_005ftable_005f0.setParent((javax.servlet.jsp.tagext.Tag) _jspx_th_s_005fform_005f0);
  第150行文件：[/color] [color=#FF0000] int _jspx_eval_s_005ftable_005f0 = _jspx_th_s_005ftable_005f0.doStartTag();    if (_jspx_eval_s_005ftable_005f0 != javax.servlet.jsp.tagext.Tag.SKIP_BODY) {
      if (_jspx_eval_s_005ftable_005f0 != javax.servlet.jsp.tagext.Tag.EVAL_BODY_INCLUDE) {
        out = _jspx_page_context.pushBody();
        _jspx_th_s_005ftable_005f0.setBodyContent((javax.servlet.jsp.tagext.BodyContent) out);
        _jspx_th_s_005ftable_005f0.doInitBody();
      }

Answer 5

我用了struts2，自己定义的国际化文件有：globalMessages_en.properties 和globalMessages_zh.properties
其中：globalMessages_en.properties中的内容如下：firstname=firstname
lastname=lastname
age=age且struts.properties内容如下
struts.custom.i18n.resources=globalMessages但是还是为发现结果出在哪里，若是单独运行update.jsp 文件无法显示该显示的内容。
update.jsp如下：
<%@ page language="java" pageEncoding="UTF-8"%><%@ taglib uri="/struts-tags" prefix="s" %><html><head>
<title>Update.jsp</title>
</head><body>
<h1><font color="red"><center>Update Users</center></font></h1>
<s:form action="updateUser">
  <s:table>
<tr>
  <td>
<s:hidden name="user.id" value="%{user.id}"></s:hidden>   </td>
</tr>

<tr>
  <td>
        <s:textfield name="user.firstname" value="%{user.firstname}" label="%{getText('firstname')}"></s:textfield>   </td>
</tr>

<tr>
  <td>
<s:textfield name="user.lastname" value="%{user.lastname}" label="%{getText('lastname')}"></s:textfield>
  </td>
</tr>

<tr>
  <td>
<s:textfield name="user.age" value="%{user.age}" label="%{getText('age')}"></s:textfield>   </td>
</tr>

<tr>
  <td>
<s:submit></s:submit>   </td>
</tr> </s:table>
</s:form>
</body>
</html>

Answer 6

明明update.jsp有错，但找不出在哪里？
update.jsp<%@ page language="java" pageEncoding="UTF-8"%><%@ taglib uri="/struts-tags" prefix="s" %><html><head>
<title>Update.jsp</title>
</head><body>
<h1><font color="red"><center>Update Users</center></font></h1>
<s:form action="updateUser">
<s:table>
<tr>
<td>
<s:hidden name="user.id" value="%{user.id}"></s:hidden>
</td>
</tr>

<tr>
<td>
<s:textfield name="user.firstname" value="%{user.firstname}" label="%{getText('firstname')}"></s:textfield>
</td>
</tr>

<tr>
<td>
<s:textfield name="user.lastname" value="%{user.lastname}" label="%{getText('lastname')}"></s:textfield>
</td>
</tr>

<tr>
<td>
<s:textfield name="user.age" value="%{user.age}" label="%{getText('age')}"></s:textfield>
</td>
</tr>

<tr>
<td>
<s:submit></s:submit>
</td>
</tr>

</s:table>
</s:form>
</body></html>

Answer 7

我知道问题出在什么地方。。
就是就是jsp页面中struts2标签的问题。。
<s:table> 
<tr> 
<td> 
这是你jsp页面中的。。你把<s:table> 和html标签一起使用
你把<s:table>改成<table>
这样就没问题了 
呵呵 我也是刚解决了这个问题