问题描述
- action调用service无限报空指针，试了很多方法都没用
-
index.jsp<%@ page language="java" import="java.util.*" pageEncoding="ISO-8859-1"%> <% String path = request.getContextPath(); String basePath = request.getScheme() + "://" + request.getServerName() + ":" + request.getServerPort() + path + "/"; %> <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"> <html> <head> <base href="<%=basePath%>"> <title>My JSP 'index.jsp' starting page</title> <meta http-equiv="pragma" content="no-cache"> <meta http-equiv="cache-control" content="no-cache"> <meta http-equiv="expires" content="0"> <meta http-equiv="keywords" content="keyword1,keyword2,keyword3"> <meta http-equiv="description" content="This is my page"> <!-- <link rel="stylesheet" type="text/css" href="styles.css"> --> </head> <body> <script type="text/javascript"> window.location.href = "Test_test.do"; </script> </body> </html>action
package com.action; import com.opensymphony.xwork2.ActionSupport; import com.service.StuService; public class TestAction extends ActionSupport { private StuService stuService; public String test() throws Exception { System.out.println("进入action"); stuService.getArraylist(); return "success"; } public StuService getStuService() { return stuService; } public void setStuService(StuService stuService) { this.stuService = stuService; } }dao
package com.dao; import com.entity.Log; public interface LogDAO { public void saveLog(Log log); public void finfLog(); }daoImpl
package com.dao.impl; import java.util.ArrayList; import java.util.Iterator; import java.util.List; import javax.annotation.Resource; import org.hibernate.Query; import org.hibernate.Session; import org.hibernate.SessionFactory; import org.springframework.stereotype.Component; import com.dao.LogDAO; import com.entity.Log; @Component public class LogDAOImpl implements LogDAO { private SessionFactory sessionfactory; public void saveLog(Log log) { Session session = sessionfactory.getCurrentSession(); session.save(log); // throw new NullPointerException(); } public void finfLog() { Session session = sessionfactory.getCurrentSession(); Query query = session.createQuery(" from Log"); ArrayList<Log> p = (ArrayList<Log>) query.list(); for (int i = 0; i < p.size(); i++) { System.out.println(p.get(i).getMassage()); } } public SessionFactory getSessionfactory() { return sessionfactory; } @Resource public void setSessionfactory(SessionFactory sessionfactory) { this.sessionfactory = sessionfactory; } }实体类
package com.entity; import javax.persistence.Entity; import javax.persistence.GeneratedValue; import javax.persistence.GenerationType; import javax.persistence.Id; import javax.persistence.SequenceGenerator; import javax.persistence.Table; @Entity @Table(name="t_log") public class Log { private int id; private String massage; public Log() { super(); } public Log(int id, String massage) { super(); this.id = id; this.massage = massage; } @Id @SequenceGenerator(name = "SEQ_STORE", sequenceName = "stu_seq") @GeneratedValue(strategy = GenerationType.SEQUENCE, generator = "SEQ_STORE") public int getId() { return id; } public void setId(int id) { this.id = id; } public String getMassage() { return massage; } public void setMassage(String massage) { this.massage = massage; } }service
package com.service; import javax.annotation.Resource; import org.springframework.stereotype.Component; import org.springframework.transaction.annotation.Transactional; import com.dao.LogDAO; import com.dao.StuDAO; import com.entity.Log; import com.entity.Stu; @Component // 业务逻辑层 public class StuService { private StuDAO stuDao; private LogDAO logDao; @Transactional public void getArraylist() throws Exception { // stuDao.getStu(); logDao.finfLog(); } @Resource public void setLogDao(LogDAO logDao) { this.logDao = logDao; } }spring配置
<?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:tx="http://www.springframework.org/schema/tx" xmlns:aop="http://www.springframework.org/schema/aop" xmlns:context="http://www.springframework.org/schema/context" xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-2.5.xsd http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-2.5.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-2.5.xsd http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop-2.5.xsd"> <context:annotation-config /> <context:component-scan base-package="com" /> <!-- 数据源 --> <bean id="DataSource" class="org.apache.commons.dbcp.BasicDataSource" destroy-method="close"> <property name="driverClassName" value="oracle.jdbc.driver.OracleDriver" /> <property name="url" value="jdbc:oracle:thin:@localhost:1521:STUDY" /> <property name="username" value="sys as SYSDBA" /> <property name="password" value="7998" /> </bean> <bean id="sessionFactory" class="org.springframework.orm.hibernate3.annotation.AnnotationSessionFactoryBean"> <property name="dataSource" ref="DataSource" /> <property name="packagesToScan"> <list> <value>com.entity</value> </list> </property> <!-- Hibernate内容 --> <property name="hibernateProperties"> <value> hibernate.dialect = org.hibernate.dialect.OracleDialect hibernate.show_sql = true hibernate.format_sql = true </value> <!-- <props> <prop key="hibernate.dialect">org.hibernate.dialect.OracleDialect</prop> <prop key="hibernate.show_sql">true</prop> </props> --> </property> </bean> <bean id="txManager" class="org.springframework.orm.hibernate3.HibernateTransactionManager"> <property name="sessionFactory" ref="sessionFactory" /> </bean> <tx:advice id="txAdvice" transaction-manager="txManager"> <tx:attributes> <tx:method name="get*" read-only="true" /> <tx:method name="*" rollback-for="Exce ption" /> </tx:attributes> </tx:advice> <aop:config> <aop:pointcut id="txPointcut" expression="execution(* com.service.*.*(..))" /> <aop:advisor advice-ref="txAdvice" pointcut-ref="txPointcut" /> </aop:config> <bean name="testAction" class="com.action.TestAction"> <property name="stuService" ref="stuService"> </property> </bean> </beans>struts配置
```<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE struts PUBLIC
"-//Apache Software Foundation//DTD Struts Configuration 2.3//EN"
"http://struts.apache.org/dtds/struts-2.3.dtd"><!-- 从2.3.16开始DMI默认是禁止的 全称是：动态方法调用 -->
<!-- -->
<!-- 约定优于配置 -->
/success.jsp
解决方案
你是不是spring配置文件里少了点什么东西，应该要加上stuService的bean吧
解决方案二：
private StuDAO stuDao;
private LogDAO logDao;
这俩个没有注入
解决方案三：
在Service中使用的两个Dao对象，需要在Srping中配置bean，在Service中提供setter方法。
private StuDAO stuDao;
private LogDAO logDao;
解决方案四：
spring配置中没有配置bean
解决方案五：
建议你把注入方式统一下，要么就采用注解注入，要么采用xml注入，这样才方便调试和查看，调试的时候在set方法里输出一些信息，看看set方法有没有被调用。
解决方案六：
spring注入配置不对，再检查
时间： 2024-09-08 19:38:04