本人自己进行的SSH整合,中间遇到不少问题,特此做些总结,仅供参考。
项目环境:
- struts-2.3.31 + spring-4.3.7 + hibernate-4.2.21 + maven + mysql5.7
首先使用maven引入相关依赖:
- pom.xml:
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd"> <modelVersion>4.0.0</modelVersion> <groupId>com.mbq.ssh-maven</groupId> <artifactId>ssh-maven</artifactId> <version>0.0.1-SNAPSHOT</version> <packaging>war</packaging> <properties> <project.build.sourceEncoding>utf-8</project.build.sourceEncoding> </properties> <!-- spring的依赖管理器,统一版本号 --> <dependencyManagement> <dependencies> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-framework-bom</artifactId> <version>4.3.7.RELEASE</version> <type>pom</type> <scope>import</scope> </dependency> </dependencies> </dependencyManagement> <dependencies> <!-- web工程所需的依赖 --> <dependency> <groupId>javax.servlet</groupId> <artifactId>javax.servlet-api</artifactId> <version>3.1.0</version> <scope>provided</scope> </dependency> <dependency> <groupId>javax.servlet.jsp</groupId> <artifactId>jsp-api</artifactId> <version>2.2</version> <scope>provided</scope> </dependency> <!-- spring整合hibernate的依赖 --> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-orm</artifactId> </dependency> <dependency> <groupId>org.hibernate</groupId> <artifactId>hibernate-core</artifactId> <version>4.2.21.Final</version> </dependency> <!-- spring使用xml方式声明式事务所需的依赖 --> <dependency> <groupId>org.aspectj</groupId> <artifactId>aspectjweaver</artifactId> <version>1.8.10</version> </dependency> <!-- c3p0数据库连接池的依赖 --> <dependency> <groupId>com.mchange</groupId> <artifactId>c3p0</artifactId> <version>0.9.5.2</version> </dependency> <!-- mysql数据库的依赖 --> <dependency> <groupId>mysql</groupId> <artifactId>mysql-connector-java</artifactId> <version>5.1.39</version> </dependency> <!-- struts2的依赖 --> <dependency> <groupId>org.apache.struts</groupId> <artifactId>struts2-core</artifactId> <version>2.3.31</version> <!-- 去除与hibernate重复的依赖 --> <exclusions> <exclusion> <groupId>javassist</groupId> <artifactId>javassist</artifactId> </exclusion> </exclusions> </dependency> <!-- spring整合struts2的依赖 --> <dependency> <groupId>org.apache.struts</groupId> <artifactId>struts2-spring-plugin</artifactId> <version>2.3.31</version> </dependency> </dependencies> </project>
一、使用XML配置:
1. 搭建Hibernate环境:
- hibernate.cfg.xml(可选,在spring中配置)
- 映射文件.hbm.xml或使用注解
2. Spring整合Hibernate:
- jdbc.properties
jdbc.driverClass=com.mysql.jdbc.Driver jdbc.url=jdbc\:mysql\://localhost\:3306/ssh?useUnicode\=true&characterEncoding\=utf8 jdbc.username=root jdbc.password=root
- 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:context="http://www.springframework.org/schema/context" xmlns:tx="http://www.springframework.org/schema/tx" xmlns:aop="http://www.springframework.org/schema/aop" xsi:schemaLocation="http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop-4.3.xsd http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-4.3.xsd http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-4.3.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-4.3.xsd"> <!-- 引入jdbc.properties --> <context:property-placeholder location="classpath:jdbc.properties"/> <!-- 注入c3p0数据源 --> <bean id="dataSource" class="com.mchange.v2.c3p0.ComboPooledDataSource" destroy-method="close"> <property name="driverClass" value="${jdbc.driverClass}"></property> <property name="jdbcUrl" value="${jdbc.url}"></property> <property name="user" value="${jdbc.username}"></property> <property name="password" value="${jdbc.password}"></property> </bean> <!-- 注入Hibernate的SessionFactory对象 --> <bean id="sessionFactory" class="org.springframework.orm.hibernate4.LocalSessionFactoryBean"> <property name="dataSource" ref="dataSource"></property> <!-- 配置Hibernate的全局配置文件 --> <!-- <property name="configLocations" value="classpath:hibernate.cfg.xml"/> --> <!-- 不使用hibernate.cfg.xml,由spring配置hibernate的属性 --> <property name="hibernateProperties"> <props> <prop key="hibernate.dialect">org.hibernate.dialect.MySQLDialect</prop> <prop key="hibernate.show_sql">true</prop> <prop key="hibernate.format_sql">true</prop> <prop key="hibernate.hbm2ddl.auto">update</prop> </props> </property> <!-- 使用通配符配置整个同一路径下的.hbm.xml --> <property name="mappingLocations" value="classpath:com/ssh/entity/*.hbm.xml"/> <!-- 配置单独的.hbm.xml --> <!-- <property name="mappingResources"> <list> <value>com/ssh/entity/User.hbm.xml</value> </list> </property> --> </bean> <!-- 注入UserDAO --> <bean id="userDao" class="com.ssh.dao.UserDAO"> <property name="sessionFactory" ref="sessionFactory"/> </bean> //Spring自动生成的是代理对象,实现了UserDao接口,不能强转为UserDaoImpl对象 /*ApplicationContext context = new ClassPathXmlApplicationContext("classpath:applicationContext.xml"); UesrDao dao = (UserDao) context.getBean("userDao");*/ //UesrDaoImpl dao = (UserDaoImpl) context.getBean("userDao"); <!-- 注入UserService --> <bean id="userService" class="com.ssh.dao.UserService"> <property name="userDao" ref="userDao"/> </bean> <!-- 配置 Spring 的声明式事务,需要引入aspectjweaver的依赖 --> <!-- 1. 配置数据源DataSource(必须) --> <!-- 2. 配置事务管理器 --> <bean id="txManager" class="org.springframework.orm.hibernate4.HibernateTransactionManager"> <property name="sessionFactory" ref="sessionFactory"></property> </bean> <!-- 3. 配置事务建议者(属性) --> <tx:advice id="txAdivce" transaction-manager="txManager"> <tx:attributes> <tx:method name="get*" read-only="true"/> <tx:method name="*" propagation="REQUIRED"/> </tx:attributes> </tx:advice> <!-- 4. 配置AOP切面 --> <aop:config> <aop:pointcut expression="execution(* com.ssh.service.*.*(..))" id="pointcut"/> <aop:advisor advice-ref="txAdivce" pointcut-ref="pointcut"/> </aop:config> <!-- 5. 不能在hibernate中配置<property name="current_session_context_class">thread</property>,否则Spring不会自动开启事务 --> </beans>
3. Spring整合Struts2
- 引入依赖:struts2-spring-plugin
- 在web.xml中配置struts2的核心过滤器及spring的监听器
<!-- 配置sprin监听器,在服务器启动时初始化IoC容器 --> <listener> <listener-class>org.springframework.web.context.ContextLoaderListener</listener-class> </listener> <!-- 默认寻找WEB-INF下的applicationContext.xml --> <context-param> <param-name>contextConfigLocation</param-name> <param-value>classpath:applicationContext*.xml</param-value> </context-param> <!-- 配置struts2过滤器 --> <filter> <filter-name>struts2</filter-name> <filter-class>org.apache.struts2.dispatcher.ng.filter.StrutsPrepareAndExecuteFilter</filter-class> </filter> <filter-mapping> <filter-name>struts2</filter-name> <url-pattern>/*</url-pattern> </filter-mapping>
- 在applicationContext.xml中注入Action
//创建一个SuperActon继承ActionSupport并实现Web元素相关的接口 <bean id="superAction" class="com.ssh.action.SuperAction" /> <!-- 必须声明 scope 属性为 prototype (非单例) --> //创建自己的Action继承SuperAction便可以直接使用request,session等对象 <bean id="userAction" class="com.ssh.action.UserAction" parent="superAction" scope="prototype"> <property name="userService" ref="userService"/> </bean>
- 配置struts.xml
<!-- class属性的值对应beans.xml中注入的Action的id名 --> <action name="user_*" class="userAction" method="{1}"> <result name="success">/success.jsp</result> </action>
二、使用注解+XML配置:
- 以下仅为不同于XML的配置
- 配置struts.xml文件时action的class值要写成Action类的全名
- 配置 applicationContext.xml:
<!-- 配置dataSource和sessionFactory --> <!-- 扫描包下的注解持久化类 --> <property name="packagesToScan" value="com.ssh.entity"></property> <!-- 开启注解式依赖与注入 --> <context:component-scan base-package="com.ssh"/> <!-- <context:annotation-config /> --> <!-- 开启注解式事务 --> <bean id="transactionManager" class="org.springframework.orm.hibernate4.HibernateTransactionManager"> <property name="sessionFactory" ref="sessionFactory"></property> </bean> <tx:annotation-driven transaction-manager="transactionManager"/>
- 注解类的配置:
@Controller @Scope("prototype") public class UserAction extends ActionSupport { @Resource private UserService userService; } @Service @Transactional public class UserService { @Resource private UserDaoImpl userDao; } @Repository("userDao") public class UserDaoImpl implements UserDao { @Resource private SessionFactory sessionFactory; } //若使用继承HibernateDaoSupport的方式,则不能直接注入SessionFactory @Repository public class UserDaoImpl extends HibernateDaoSupport implements UserDao { @Resource public void setSuperSessionFactory(SessionFactory sessionFactory) { super.setSessionFactory(sessionFactory); } }
LazyInitializationException问题:
- 问题:一对多映射时,获取一方对象时同时获取到的是多方的代理对象(延迟加载),在view层调用时抛出org.hibernate.LazyInitializationException:could not initialize proxy - no Session,即代理对象不能被初始化
- 原因:在service层添加了事务,事务提交时将session关闭了,所以在view层就不能再使用session获取数据。
- 解决办法:
- 修改一对多映射中的set的lazy属性值为false。
- 获取一方对象时使用迫切左外连接(left join fetch)同时初始化其关联的多方对象。
- 在web.xml中配置一个过滤器:OpenSessionInViewFilter
<!-- 此过滤器必须配置在struts2过滤器的前面 --> <filter> <filter-name>OpenSessionInViewFilter</filter-name> <filter-class>org.springframework.orm.hibernate4.support.OpenSessionInViewFilter</filter-class> </filter> <filter-mapping> <filter-name>OpenSessionInViewFilter</filter-name> <url-pattern>*.action</url-pattern> </filter-mapping>
以上即为SSH配置的基本过程,若有不足之处还望大家提出自己的想法及意见。
时间: 2024-09-30 07:24:18