第十一讲 使用注解开发

一、spring配置文件（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: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.xsd

     http://www.springframework.org/schema/tx

     http://www.springframework.org/schema/tx/spring-tx.xsd

     http://www.springframework.org/schema/aop

     http://www.springframework.org/schema/aop/spring-aop.xsd

     http://www.springframework.org/schema/context

     http://www.springframework.org/schema/context/spring-context.xsd" >

      <!-- 配置数据源 -->

      < bean id = "dataSource"

           class = "org.springframework.jdbc.datasource.DriverManagerDataSource" >

            < property name = "driverClassName" value = "com.mysql.jdbc.Driver" ></ property >

            < property name = "url" value = "jdbc:mysql://localhost:3306/test" ></ property >

            < property name = "username" value = "root" ></ property >

            < property name = "password" value = "123456" ></ property >

      </ bean >

      <!-- 声明式事务配置 -->

      <!-- 配置事务管理器 -->

      < bean id = "txManager"

           class = "org.springframework.jdbc.datasource.DataSourceTransactionManager" >

            < property name = "dataSource" ref = "dataSource" />

      </ bean >

      <!-- 配置事务通知 -->

      < tx:advice id = "txAdvice" transaction-manager = "txManager" >

            < tx:attributes >

                 <!-- 配置哪些方法使用什么样的事务，配置事务的传播特性 -->

                 < tx:method name = "add" propagation = "REQUIRED" />

                 < tx:method name = "insert" propagation = "REQUIRED" />

                 < tx:method name = "update" propagation = "REQUIRED" />

                 < tx:method name = "delete" propagation = "REQUIRED" />

                 < tx:method name = "remove*" propagation = "REQUIRED" />

                 < tx:method name = "get" read-only = "true" />

                 < tx:method name = "*" propagation = "REQUIRED" />

            </ tx:attributes >

      </ tx:advice >

      < aop:config >

            <!-- 切入点应该是service.impl下的所有类的所有方法，这里为了方便测试所以直接用了dao.impl -->

            < aop:pointcut expression = "execution(* com.liujie.dao.impl.*.*(..))"

                 id = "pointcut" />

            < aop:advisor advice-ref = "txAdvice" pointcut-ref = "pointcut" />

      </ aop:config >

      <!-- 声明式事务配置结束 -->

      <!-- 配置sqlSessionFactory -->

      < bean id = "sqlSessionFactory" class = "org.mybatis.spring.SqlSessionFactoryBean" >

            < property name = "dataSource" ref = "dataSource" ></ property >

            < property name = "configLocation" value = "classpath:mybatis-config.xml" ></ property >

      </ bean >

      <!-- 自动扫描所配置包下的所有注解

           dao：@Repository("userDao")

           service：@Service("userService")

           action：@Controller("userAction") @Scope("prototype")

           属性的注入：@Autowired

      -->

      <context:component-scan base-package="com.liujie"></context:component-scan>

</ beans >

二、spring注解：

      UserDaoImpl.java：

@Repository("userDao") public class UserDaoImpl extends SqlSessionDaoSupport implements UserDao {       @Autowired       @Override       public void setSqlSessionFactory(SqlSessionFactory sqlSessionFactory ) {             super .setSqlSessionFactory( sqlSessionFactory );      }             public List<User> getAll() {             return this .getSqlSession().selectList( "com.liujie.model.UserMapper.getAll" );      } }

< bean id = "userDao" class = "com.liujie.dao.impl.UserDaoImpl" >             < property name = "sqlSessionFactory" ref = "sqlSessionFactory" ></ property >       </ bean >

@Repository("userDao")，相当于是创建一个 id="userDao"的 bean； @Autowired，可以写在要注入的 属性上面，也可以写在要注入 的 属性的setter方法上面，注入的值是 id=属性名的 bean。

      UserServiceImpl.java：

@Service ( "userService" ) public class UserServiceImpl implements UserService {       @Autowired       private UserDao userDao ;             public void setUserDao(UserDao userDao ) {             this . userDao = userDao ;      }             public List<User> getAll() {             return userDao .getAll();      } }

为什么上面UserDaoImpl.java里面， @Repository("userDao")中一定要写 "userDao"呢？    因为这里要 注入UserDao的属性名为userDao，如果UserDaoImpl.java里面直接写 @Repository，默认创建的bean的    id=类名（userDaoImpl），所以要么在UserDaoImpl.java里面写 @Repository("userDao")，要么把这里 private UserDao userDao改    写为 private UserDao userDaoImpl。

      UserAction.java：

@Controller ( "userAction" )

@Scope("prototype")

public class UserAction {

      private List<User> list ;

     

      @Autowired

      private UserService userService ;

     

      public void setUserService(UserService userService ) {

            this . userService = userService ;

     }

     

      public List<User> getList() {

            return list ;

     }

     

      public void setList(List<User> list ) {

            this . list = list ;

     }

     

      public String list() {

            list = userService .getAll();

            return "success" ;

     }

     

}

三、总结：

< bean id = "userDao" class = "com.liujie.dao.impl.UserDaoImpl" >             < property name = "sqlSessionFactory" ref = "sqlSessionFactory" ></ property >       </ bean >             < bean id = "userService" class = "com.liujie.service.impl.UserServiceImpl" >             < property name = "userDao" ref = "userDao" ></ property >       </ bean >             < bean id = "userAction" class = "com.liujie.action.UserAction" scope = "prototype" >             < property name = "userService" ref = "userService" ></ property >       </ bean >

其实就是用注解的方式来生成这3个bean。