这里使用Spring3.0+Hibernate3.3作为例子。
例子中的实体类也是用的Hibernate注解里的实体(上一篇Blog)
一、Spring的一些常用注解
1.@Autowired注解(不推荐使用,建议使用@Resource)
@Autowired可以对成员变量、方法和构造函数进行标注,来完成自动装配的工作。@Autowired的标注位置不同,它们都会在Spring在初始化这个bean时,自动装配这个属性。
2.@Resource注解
JSR-250标准注解,推荐使用它来代替Spring专有的@Autowired注解。@Resource的作用相当于@Autowired,只不过@Autowired按byType自动注入,而@Resource默认按byName自动注入罢了。@Resource有两个属性是比较重要的,分别是name和type,Spring将 @Resource注解的name属性解析为bean的名字,而type属性则解析为bean的类型。所以如果使用name属性,则使用byName的自动注入策略,而使用type属性时则使用byType自动注入策略。如果既不指定name也不指定type属性,这时将通过反射机制使用byName自动注入策略。
@Resource装配顺序:
a.如果同时指定了name和type,则从Spring上下文中找到唯一匹配的bean进行装配,找不到则抛出异常
b.如果指定了name,则从上下文中查找名称(id)匹配的bean进行装配,找不到则抛出异常
c.如果指定了type,则从上下文中找到类型匹配的唯一bean进行装配,找不到或者找到多个,都会抛出异常
d.如果既没有指定name,又没有指定type,则自动按照byName方式进行装配(见2);如果没有匹配,则回退为一个原始类型(UserDao)进行匹配,如果匹配则自动装配
3.@Component注解 (不推荐使用)
只需要在对应的类上加上一个@Component注解,就将该类定义为一个Bean了。Spring还提供了更加细化的注解形式:@Repository、@Service、@Controller,它们分别对应存储层Bean,业务层Bean,和展示层Bean。这些注解与@Component的语义是一样的,完全通用,在Spring以后的版本中可能会给它们追加更多的语义。所以,我们推荐使用@Repository、@Service、@Controller来替@Component。
二、Spring3.0的头部文件
<?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:aop="http://www.springframework.org/schema/aop" xmlns:tx="http://www.springframework.org/schema/tx" 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/aop http://www.springframework.org/schema/aop/spring-aop-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/context http://www.springframework.org/schema/context/spring-context-3.0.xsd"> </beans>
三、dao和daoImpl
dao:
package org.e276.dao; import java.util.List; import org.e276.entity.Employee; /** * 接口 * * @author miao * */ public interface EmployeeDao { /** * 根据id查询员工 * * @param id * @return */ public Employee findEmployeeById(Integer id); /** * 删除多个员工 * * @param ids * @return */ public int deleteEmployees(Integer... ids); /** * 查询所有的工资,并按升序排序 * * @return */ public List<Employee> findAllEmployees(); /** * 查询所有大于平均工资的员工信息 * * @return */ public List<Employee> findEmployeeGtAvgSalary(); }
daoImpl:
package org.e276.dao.impl; import java.sql.SQLException; import java.util.List; import org.e276.dao.EmployeeDao; import org.e276.entity.Employee; import org.hibernate.HibernateException; import org.hibernate.Query; import org.hibernate.Session; import org.hibernate.SessionFactory; import org.hibernate.criterion.DetachedCriteria; import org.hibernate.criterion.Order; import org.springframework.beans.factory.annotation.Autowired; import org.springframework.orm.hibernate3.HibernateCallback; import org.springframework.orm.hibernate3.support.HibernateDaoSupport; import org.springframework.stereotype.Repository; /** * 接口实现类 * * @author miao * */ @Repository("employeeDao") public class EmployeeDaoImpl extends HibernateDaoSupport implements EmployeeDao { /** * 注入会话工厂,方法名字在可以随便起,给Spring用来注入 */ @Autowired public void injectSessionFactory(SessionFactory sessionFactory) { super.setSessionFactory(sessionFactory); } @Override public Employee findEmployeeById(Integer id) { return super.getHibernateTemplate().get(Employee.class, id); } @Override public int deleteEmployees(Integer... ids) { int count = 0; for (Integer id : ids) { super.getHibernateTemplate().bulkUpdate("delete from Employee where id=?", id); count++; } return count; } @SuppressWarnings("unchecked") @Override public List<Employee> findAllEmployees() { DetachedCriteria criteria = DetachedCriteria.forClass(Employee.class); criteria.addOrder((Order.asc("salary"))); return super.getHibernateTemplate().findByCriteria(criteria); } @SuppressWarnings({ "unchecked", "rawtypes" }) @Override public List<Employee> findEmployeeGtAvgSalary() { return (List<Employee>) super.getHibernateTemplate().execute(new HibernateCallback() { String sql = "select id, name, sex, salary, birthday, depart_id from employee where salary>(select avg(salary) from employee)"; @Override public Object doInHibernate(Session session) throws HibernateException, SQLException { Query query = session.createSQLQuery(sql).addEntity(Employee.class); return query.list(); } }); } }
四、biz和bizImpl
biz:
package org.e276.biz; import java.util.List; import org.e276.entity.Employee; import org.springframework.transaction.annotation.Transactional; /** * 业务接口 * * @author miao * */ public interface EmployeeBiz { /** * 根据id查询员工 * * @param id * @return */ public Employee findEmployeeById(Integer id); /** * 删除多个员工,支持注解事务 * * @param ids * @return */ @Transactional public int deleteEmployees(Integer... ids); /** * 查询所有的工资,并按升序排序 * @return */ public List<Employee> findAllEmployees(); /** * 查询所有大于平均工资的员工信息 * @return */ public List<Employee> findEmployeeGtAvgSalary(); }
bizImpl:
package org.e276.biz.impl; import java.util.List; import org.e276.biz.EmployeeBiz; import org.e276.dao.EmployeeDao; import org.e276.entity.Employee; import org.springframework.beans.factory.annotation.Autowired; import org.springframework.stereotype.Service; /** * 业务接口实现类 * @author miao * */ @Service("employeeBiz") public class EmployeeBizImpl implements EmployeeBiz { //无需set方法 @Autowired private EmployeeDao employeeDao; @Override public Employee findEmployeeById(Integer id) { return employeeDao.findEmployeeById(id); } @Override public int deleteEmployees(Integer... ids) { return employeeDao.deleteEmployees(ids); } @Override public List<Employee> findAllEmployees() { return employeeDao.findAllEmployees(); } @Override public List<Employee> findEmployeeGtAvgSalary() { return employeeDao.findEmployeeGtAvgSalary(); } }
五、Spring的配置文件
<?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:aop="http://www.springframework.org/schema/aop" xmlns:tx="http://www.springframework.org/schema/tx" 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/aop http://www.springframework.org/schema/aop/spring-aop-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/context http://www.springframework.org/schema/context/spring-context-3.0.xsd"> <!-- 哪个包里面的类由Spring管理 --> <context:component-scan base-package="org.e276" /> <!-- 表示隐式的向Spring容器注册 --> <context:annotation-config /> <!-- 会话工厂 --> <bean id="sessionFactory" class="org.springframework.orm.hibernate3.annotation.AnnotationSessionFactoryBean"> <property name="configLocation" value="file:src/hibernate.cfg.xml"> </property> </bean> <!-- 事务管理器 --> <bean id="transactionManager" class="org.springframework.orm.hibernate3.HibernateTransactionManager"> <property name="sessionFactory"> <ref bean="sessionFactory" /> </property> </bean> <!-- 有关注解式事务的配置 --> <tx:annotation-driven transaction-manager="transactionManager" /> </beans>
六、测试类
package org.e276.test; import java.util.List; import org.e276.biz.EmployeeBiz; import org.e276.entity.Employee; import org.junit.After; import org.junit.AfterClass; import org.junit.Before; import org.junit.BeforeClass; import org.junit.Test; import org.springframework.context.ApplicationContext; import org.springframework.context.support.ClassPathXmlApplicationContext; /** * 测试类 * * @author miao * */ public class SpringEmployee { static ApplicationContext context; EmployeeBiz employeeBiz; @BeforeClass public static void setUpBeforeClass() throws Exception { context = new ClassPathXmlApplicationContext("applicationContext.xml"); } @AfterClass public static void tearDownAfterClass() throws Exception { context = null; } @Before public void setUp() throws Exception { employeeBiz = context.getBean("employeeBiz", EmployeeBiz.class); } @After public void tearDown() throws Exception { employeeBiz = null; } /** * 根据id查询员工 */ public void findEmployeeById() { Employee employee = employeeBiz.findEmployeeById(1000); System.out.println(employee); } /** * 删除多条记录 删除编号50,100,150的员工 */ public void deleteEmployees() { int row = employeeBiz.deleteEmployees(50, 100, 150); System.out.println("共" + row + "条记录被删除!"); } /** * 查询所有的员工,并按工资升序排序 */ public void findAllEmployees() { List<Employee> list = employeeBiz.findAllEmployees(); for (Employee employee : list) { System.out.println(employee); } } /** * 查询所有大于平均工资的员工信息 */ @Test public void findEmployeeGtAvgSalary() { List<Employee> list = employeeBiz.findEmployeeGtAvgSalary(); for (Employee employee : list) { System.out.println(employee); } } }
七、demo