Spring框架七大模块简单介绍

Spring中MVC模块代码详解

ORM模块对Hibernate、JDO、TopLinkiBatis等ORM框架提供支持

ORM模块依赖于dom4j.jar、antlr.jar等包

在Spring里，Hibernate的资源要交给Spring管理，Hibernate以及其SessionFactory等知识Spring一个特殊的Bean，有Spring负责实例化与销毁。因此DAO层只需要继承HibernateDaoSupport，而不需要与Hibernate的API打交道，不需要开启、关闭Hibernate的Session、Transaction，Spring会自动维护这些对象

public interface ICatDao{ public void createCat(Cat cat); public List<Cat> listCats(); public int getCatsCount(); public Cat findCatByName(String name); } import org.springframework.orm.hibernate3.support.HibernateDaoSupport; public class CatDaoImpl extends HibernateDaoSupportimplements ICatDao{ public void createCat(Cat cat){ this.getHibernateTemplate().persist(cat); } public List<Cat> listCats(){ return this. getHibernateTemplate().find("select cfrom Cat c"); } public int getCatsCount(){ Number n = (Number)this.getSession(true).createQuery("selectcount(c) from Cat c").uniqueResult(); return n.intValue(); } public Cat findCatByName(String name){ List<Cat> catList =this.getHibernateTemplate().find("select c from Cat where c.name = ?",name); if(catList.size()>0) return catList.get(0); return null; } } <bean id="sessionFactory" class="org.springframework.orm.hibernate3.annotation.AnnotationSessionFactoryBean" destroy-method="destroy"> <property name="dataSource" ref="dataSource" /> <!-- 该Package下的所有类都会被当做实体类加载--> <property name="annotatedPackages" value="classpath:/com/clf/orm" /> <property name="anotatedClasses"> <list> <value>com.clf.spring.orm.Cat</value> <value>com.clf.spring.orm.Dog</value> </list> <property name="hibernateProperties"> <props> <prop key="hiberante.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">create</prop> </props> </property> <bean id="catDao" class="com.clf.spring.orm.CatDaoImpl"> <property name="sessionFactory" ref=" sessionFactory"/> </bean>

如果使用XML配置的实体类，则改为

<bean id="sessionFactory" class="org.springframework.orm.hibernate3.LocalSessionFactoryBean" destroy-method="destroy"> <property name="mappingResources"> <list> <value>classpath:/com/clf/orm/Cat.hbm.xml</value> </list> </property> …… </bean>

Spring默认在DAO层添加事务，DAO层的每个方法为一个事务。Spring+Hibernate编程中，习惯的做法实在DAO层上再添加一个Service层，然后把事务配置在Service层

public interface ICatService{ public void createCat(Cat cat); public List<Cat> listCats(); public int getCatsCount(); }

分层的做法是，程序调用Service层，Service层调用DAO层，DAO层调用Hibernate实现数据访问，原则上不允许跨曾访问。分层使业务层次更加清晰

public class CatServiceImpl implements ICatService{ private IDao catDao; public IDao getCatDao(){ return catDao; } public void setCatDao(IDao dao){ this.catDao = dao; } public void createCat(Cat cat){ catDao.createCat(cat); } public List<Cat> listCats(){ return catDao.listCats(); } public int getCatsCount(){ return catDao.getCatsCount(); } }

然后再Service层配置事务管理

<!-- 事务管理器--> <bean id="hibernateTransactionManager" class=" org.springframework.orm.hibernate3.HibernateTransactionManager "> <property name="sessionFactory" ref="sessionFactory"/> </bean> <!-- 事务管理规则--> <bean id="hibernateTransactionAttributeSource" class=" org.springframework.transaction.interceptor.NameMatchTransactionAttributeSource"> <property name="properties"> <props><!-- 为所有方法加上事务--> <propkeypropkey="*">PROPGATION_REQUIRED</prop> </property> </bean> <!-- 事务工厂代理类，将Service实现类、事务管理器、事务管理规则组装在一起--> <bean id="catService" class="org.springframework.transaction.interceptor.TransactionProxyFactoryBean"> <property name="transactionManager" ref=" hibernateTransactionManager"> <property name="target"> <bean class="com.clf.spring.orm.CatServiceImpl" > <property name="catDao" ref="catDao"/> </bean> </property> <property name="transactionAttributeSource" ref=" hibernateTransactionAttributeSource" /> </bean>

总结

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