SSH使用注解方式出异常 求教
一个简单的SSH(struts2.1 + hibernate3.3 + spring3.0)例子改为用注解配置后启动tomcat报错：
Exception sending context initialized event to listener instance of class org.springframework.web.context.ContextLoaderListener
org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'userAction' defined in file [C:\Program Files\Apache Software Foundation\apache-tomcat-7.0.5\webapps\ssh5\WEB-INF\classes\com\lm\struts2\userAction.class]: Instantiation of bean failed; nested exception is org.springframework.beans.BeanInstantiationException: Could not instantiate bean class [com.lm.struts2.userAction]: Constructor threw exception; nested exception is java.lang.NullPointerException
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.instantiateBean(AbstractAutowireCapableBeanFactory.java:946)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBeanInstance(AbstractAutowireCapableBeanFactory.java:892)
.............
Caused by: org.springframework.beans.BeanInstantiationException: Could not instantiate bean class [com.lm.struts2.userAction]: Constructor threw exception; nested exception is java.lang.NullPointerException
at org.springframework.beans.BeanUtils.instantiateClass(BeanUtils.java:141)
..................
Caused by: java.lang.NullPointerException
at org.apache.struts2.ServletActionContext.getRequest(ServletActionContext.java:112)
at com.lm.struts2.userAction.<init>(userAction.java:21)
意思好像是不能初始化UserAction
下面是配置文件
applicationContext.xml:
<?xml version="1.0" encoding="UTF-8"?><beans xmlns="http://www.springframework.org/schema/beans" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:p="http://www.springframework.org/schema/p" xmlns:context="http://www.springframework.org/schema/context" xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-3.0.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-3.0.xsd" default-autowire="byName"> <context:annotation-config /> <context:component-scan base-package="com.lm"></context:component-scan> <bean id="dataSource" class="org.apache.commons.dbcp.BasicDataSource" destroy-method="close"> <property name="driverClassName" value="com.mysql.jdbc.Driver"> </property> <property name="url" value="jdbc:mysql://127.0.0.1:3306"></property> <property name="username" value="root"></property> <property name="password" value="lm"></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="configLocation" value="classpath:hibernate.cfg.xml"> </property> <property name="dataSource" ref="dataSource"></property> </bean></bean>
<?xml version="1.0" encoding="UTF-8" ?><!DOCTYPE struts PUBLIC "-//Apache Software Foundation//DTD Struts Configuration 2.1//EN" "http://struts.apache.org/dtds/struts-2.1.dtd"><struts><package name="suibiaojiao" extends="struts-default" namespace="/" > <action name="*_*" class="com.lm.struts2.{1}Action" method="{2}" > <result name="ok" type="redirect">user_findAll.action</result> <result name="error">/error.jsp</result> <result name="findAllOK">/studentList.jsp</result> <result name="deleteOK" type="redirect">user_findAll.action</result> <result name="input" >/save.jsp</result> <result name="updatePOK" >/update.jsp</result> <result name="updateOK" type="redirect">user_findAll.action</result> </action> </package></struts>
package com.lm.Impdao;import java.util.List;import javax.annotation.Resource;import org.aspectj.weaver.patterns.ThisOrTargetAnnotationPointcut;import org.hibernate.Query;import org.hibernate.Session;import org.slf4j.Logger;import org.slf4j.LoggerFactory;import org.springframework.context.ApplicationContext;import org.springframework.orm.hibernate3.support.HibernateDaoSupport;import org.springframework.stereotype.Repository;import com.lm.Idao.IStudentDAO;import com.lm.dao.Student;@Repositorypublic class StudentDAO extends HibernateDaoSupport implements IStudentDAO{ //此处代码省略}package com.lm.Impbiz;import java.io.ByteArrayInputStream;import java.io.ByteArrayOutputStream;import java.io.IOException;import java.io.InputStream;import java.util.List;import javax.annotation.Resource;import org.apache.poi.hssf.usermodel.HSSFCell;import org.apache.poi.hssf.usermodel.HSSFRow;import org.apache.poi.hssf.usermodel.HSSFSheet;import org.apache.poi.hssf.usermodel.HSSFWorkbook;import org.springframework.stereotype.Service;import com.lm.Idao.IStudentDAO;import com.lm.biz.IStudentBiz;import com.lm.dao.Student;@Servicepublic class StudentBiz implements IStudentBiz { @Resource private IStudentDAO studentDAO; public void setStuDAO(IStudentDAO stuDAO) { this.studentDAO = stuDAO; } public boolean login(Student stu) { return studentDAO.findByExample(stu).size() > 0; } public List<Student> findAll() { return studentDAO.findAll(); } public boolean save(Student stu){ boolean flag=false; try{ if(studentDAO.findByExample(stu).size() == 0){ studentDAO.save(stu); flag=true; } }catch(Exception ex){ } return flag; } public boolean delete(int stuId){ boolean flag=false; try{ studentDAO.delete(stuId); flag=true; }catch(Exception ex){ ex.printStackTrace(); } return flag; } public Student findById(int stuId) { return studentDAO.findById(stuId); } public boolean update(Student stu) { if(studentDAO.merge(stu) != null) return true; else return false; }}package com.lm.struts2;import java.io.InputStream;import java.io.PrintWriter;import java.util.List;import javax.annotation.Resource;import javax.servlet.http.HttpServletRequest;import javax.servlet.http.HttpSession;import org.apache.struts2.ServletActionContext;import org.springframework.stereotype.Controller;import com.lm.biz.IStudentBiz;import com.lm.dao.Student;import com.opensymphony.xwork2.ActionSupport;@Controllerpublic class userAction extends ActionSupport {HttpServletRequest request=ServletActionContext.getRequest();HttpSession session=request.getSession();@Resourceprivate Student stu;private IStudentBiz studentBiz;public void setStuBiz(IStudentBiz stuBiz) {this.studentBiz = stuBiz;}public Student getStu() {return stu;}public void setStu(Student stu) {this.stu = stu;}public String save() throws Exception{String tag="error";if(studentBiz.save(stu))tag="ok";return tag;}public String findAll() throws Exception{String tag="error";try{List<Student> stus = studentBiz.findAll();tag="findAllOK";request.setAttribute("stus", stus);}catch(Exception ex){ex.printStackTrace();}return tag;}public String delete() throws Exception{String tag="error";try{if(studentBiz.delete(stu.getStuId()))tag="deleteOK";}catch(Exception ex){ex.printStackTrace();}return tag;} public String updateP() throws Exception{stu=studentBiz.findById(stu.getStuId());return "updatePOK";} public String updatesave() throws Exception{String tag="error";if(studentBiz.update(stu))tag="updateOK";return tag;} }