关于spring+hibernate整合的一些问题
三大框架的整合,在dao的实现层,由于使用的是hibernate4+spring3,hibernate4拥有更好的事物管理机制,所以dao层不需要再继承HibernateSupportDao类,(目前没有找到好的方法获取session),所以采用最原始的方法: 关于获取session的做法可以这样,通过注入sessionFactory属性然后用最基本的方法进行获取
(一):通过sessionFactory.openSession()方法获取session。此方法获取一个新的session,该session需要手动进行关闭(一般都不采用这个,因为手动关太麻烦了)
(二):通过sessionFactory.getCurrentSession()方法获取session。此方法可以获取与线程绑定的session,此方法获到的session,Spring框架会帮你进行管理,说白了就是会自动进行关闭(推荐此方法,方便省事)。但要用这个方法,一般都会抛出一个异常
该异常的意思在线程中没有找到这个session(估计是没创建吧,有兴趣的话可以深入百度下),我在网上搜了下,测试有两种方法可以解决这个问题:
1. 在spring配置文件中加上事物管理器代码,同时加上注解进行事物配置(当然也可以使用声明式事物)
<bean id="transactionManager" class="org.springframework.orm.hibernate4.HibernateTransactionManager">
<property name="sessionFactory" ref="sessionFactory" /> <!-- 事务中获取session时,是从这里获取的 -->
</bean>
<tx:annotation-driven transaction-manager="transactionManager"/>
然后再在你的接口dao(注意这里是接口,不是实现dao)的方法中添加事物的注解,例如这样
即可解决这个问题,不过当获取关联对象的时候会有懒加载的问题(这里就不说这个问题)
2.说到第二种方法,跟第一种方法有点类似, 唯一不同的是可以在实现dao的实现层加入注解(不在接口层加),不过这里要引入cglib-nodep-2.1_3.jar包,不然就会报错。
好了说到这里,顺便记录下maven配置SSH用到的pom.xml文件:
<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/maven-v4_0_0.xsd">
<modelVersion>4.0.0</modelVersion>
<groupId>SSH</groupId>
<artifactId>SSH</artifactId>
<packaging>war</packaging>
<version>0.0.1-SNAPSHOT</version>
<name>SSH Maven Webapp</name>
<url>http://maven.apache.org</url>
<dependencies>
<dependency>
<groupId>junit</groupId>
<artifactId>junit</artifactId>
<version>3.8.1</version>
<scope>test</scope>
</dependency>
<dependency>
<groupId>org.apache.struts</groupId>
<artifactId>struts2-core</artifactId>
<version>2.3.16</version>
<exclusions>
<exclusion>
<groupId>javassist</groupId>
<artifactId>javassist</artifactId>
</exclusion>
</exclusions>
</dependency>
<!-- spring3 -->
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-core</artifactId>
<version>3.1.2.RELEASE</version>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-context</artifactId>
<version>3.1.2.RELEASE</version>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-jdbc</artifactId>
<version>3.1.2.RELEASE</version>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-beans</artifactId>
<version>3.1.2.RELEASE</version>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-web</artifactId>
<version>3.1.2.RELEASE</version>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-expression</artifactId>
<version>3.1.2.RELEASE</version>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-orm</artifactId>
<version>3.1.2.RELEASE</version>
</dependency>
<dependency>
<groupId>org.apache.struts</groupId>
<artifactId>struts2-spring-plugin</artifactId>
<version>2.3.4.1</version>
</dependency>
<!-- log4j -->
<dependency>
<groupId>log4j</groupId>
<artifactId>log4j</artifactId>
<version>1.2.17</version>
</dependency>
<dependency>
<groupId>junit</groupId>
<artifactId>junit</artifactId>
<version>4.12</version>
<scope>test</scope>
</dependency>
<!-- hibernate4 -->
<dependency>
<groupId>org.hibernate</groupId>
<artifactId>hibernate-core</artifactId>
<version>4.1.7.Final</version>
</dependency>
<!-- mysql数据库驱动 -->
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
<version>5.1.21</version>
</dependency>
<!-- druid -->
<dependency>
<groupId>com.alibaba</groupId>
<artifactId>druid</artifactId>
<version>0.2.8</version>
</dependency>
<!-- aspectjweaver -->
<dependency>
<groupId>org.aspectj</groupId>
<artifactId>aspectjweaver</artifactId>
<version>1.7.0</version>
</dependency>
<!-- jstl -->
<dependency>
<groupId>javax.servlet</groupId>
<artifactId>jstl</artifactId>
<version>1.2</version>
</dependency>
<dependency>
<groupId>javax.servlet.jsp</groupId>
<artifactId>jsp-api</artifactId>
<version>2.2.1-b03</version>
<scope>provided</scope>
</dependency>
<!-- fastJson -->
<dependency>
<groupId>com.alibaba</groupId>
<artifactId>fastjson</artifactId>
<version>1.1.24</version>
</dependency>
<!-- servlet -->
<dependency>
<groupId>javax.servlet</groupId>
<artifactId>servlet-api</artifactId>
<version>2.5</version>
<scope>provided</scope>
</dependency>
<!-- https://mvnrepository.com/artifact/commons-dbcp/commons-dbcp -->
<dependency>
<groupId>commons-dbcp</groupId>
<artifactId>commons-dbcp</artifactId>
<version>1.4</version>
</dependency>
</dependencies>
<build>
<finalName>SSH</finalName>
</build>
</project>
web.xml文件
<?xml version="1.0" encoding="UTF-8"?>
<web-app version="2.5" xmlns="http://java.sun.com/xml/ns/javaee"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://java.sun.com/xml/ns/javaee
http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd">
<context-param>
<param-name>contextConfigLocation</param-name>
<param-value>classpath:/Spring.xml</param-value>
</context-param>
<!-- 配置Spring监听器 -->
<listener>
<listener-class>org.springframework.web.context.ContextLoaderListener</listener-class>
</listener>
<!-- 配置Struts2的主过滤器 -->
<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>
<welcome-file-list>
<welcome-file>index.jsp</welcome-file>
</welcome-file-list>
</web-app>
相关的Spring配置文件
<?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:tx="http://www.springframework.org/schema/tx"
xmlns:aop="http://www.springframework.org/schema/aop"
xsi:schemaLocation="http://www.springframework.org/schema/beans
http://www.springframework.org/schema/beans/spring-beans-3.0.xsd
http://www.springframework.org/schema/tx
http://www.springframework.org/schema/tx/spring-tx-3.0.xsd
http://www.springframework.org/schema/aop
http://www.springframework.org/schema/aop/spring-aop-3.0.xsd">
<!-- 配置数据源 -->
<bean id="dataSource" class="org.apache.commons.dbcp.BasicDataSource">
<property name="driverClassName" value="com.mysql.jdbc.Driver"></property>
<property name="url" value="jdbc:mysql://localhost:3306/test4"></property>
<property name="username" value="root"></property>
<property name="password" value="123"></property>
</bean>
<bean id="sessionFactory" class="org.springframework.orm.hibernate4.LocalSessionFactoryBean">
<property name="dataSource">
<ref bean="dataSource" />
</property>
<property name="hibernateProperties">
<props>
<prop key="hibernate.dialect">org.hibernate.dialect.MySQLDialect</prop>
<prop key="show_sql">true</prop>
</props>
</property>
<property name="mappingResources">
<list>
<value>entity/Student.hbm.xml</value>
<value>entity/Classes.hbm.xml</value>
</list>
</property>
</bean>
<bean id="stuAction" class="action.StuAction">
<property name="sd" ref="stuDao"></property>
</bean>
<bean id="stuDao" class="daoImpl.StuDaoImpl">
<property name="sessionFactory" ref="sessionFactory"></property>
</bean>
<bean id="transactionManager" class="org.springframework.orm.hibernate4.HibernateTransactionManager">
<property name="sessionFactory" ref="sessionFactory" /> <!-- 事务中获取session时,是从这里获取的 -->
</bean>
<tx:annotation-driven transaction-manager="transactionManager"/>
<!-- <aop:config proxy-target-class="true"></aop:config>-->
</beans>