13Spring - Spring转账Demo（了解事务及AOP）

Spring的转账案例

1）代码准备

1）创建业务层

public interface AccountService {
    public void transfer(String from, String to, Double money);
}

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public class AccountServiceImpl implements AccountService {
    // 业务层注入 DAO:
    private AccountDao accountDao;

    public void setAccountDao(AccountDao accountDao) {
        this.accountDao = accountDao;
    }

    @Override
    /**
     * from:转出的账号
     * to:转入的账号
     * money：转账金额
     */
    public void transfer(String from, String to, Double money) {
        accountDao.outMoney(from, money);
        accountDao.inMoney(to, money);
    }
}

2）创建DAO类

public interface AccountDao {

    public void outMoney(String from, Double money);

    public void inMoney(String to, Double money);
}

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public class AccountDaoImpl extends JdbcDaoSupport implements AccountDao {

    @Override
    public void outMoney(String from, Double money) {
        this.getJdbcTemplate().update("update account set money = money - ? where
                name = ? ", money,from);
    }

    @Override
    public void inMoney(String to, Double money) {
        this.getJdbcTemplate().update("update account set money = money + ? where
                name = ? ", money,to);
    }
}

3）配置业务层和DAO类

<!-- 配置业务层的类 -->
<bean  id="accountService" class="cn.itcast.transaction.demo1.AccountServiceImpl">
		<property name="accountDao" ref="accountDao"/>
</bean>

<!-- 配置 DAO 的类 -->
<bean id="accountDao" class="cn.itcast.transaction.demo1.AccountDaoImpl">
		<property name="dataSource" ref="dataSource"/>
</bean>

3）测试

@RunWith(SpringJUnit4ClassRunner.class)
@ContextConfiguration("classpath:applicationContext2.xml")
public class SpringDemo4 {
    @Resource(name = "accountService")
    private AccountService accountService;

    @Test
    // 转账的测试:
    public void demo1() {
        accountService.transfer("会希", "凤姐", 1000d);
    }
}

第一种 - Spring的编程式事务

1)配置事务管理器

<bean  id="transactionManager" class="org.springframework.jdbc.datasource.DataSourceTransactionManager">
		<property name="dataSource" ref="dataSource"/>
</bean>

2）配置事务管理模板

<bean id="transactionTemplate" class="org.springframework.transaction.support.TransactionTemplate">
		<property name="transactionManager" ref="transactionManager"/>
</bean>

3）业务层注入事务管理模板

<!-- 配置业务层的类 -->
<bean id="accountService" class="cn.itcast.transaction.demo1.AccountServiceImpl">
	
	<property name="accountDao" ref="accountDao"/>
	
	<!-- 注入事务管理模板 -->
	<property name="transactionTemplate" ref="transactionTemplate"/>
</bean>

4）代码实现

 public void transfer(final String from, final String to, final Double money) {
        transactionTemplate.execute(new TransactionCallbackWithoutResult() {
            @Override
            protected void doInTransactionWithoutResult(TransactionStatus status) {
                accountDao.outMoney(from, money);
                int d = 1 / 0;
                accountDao.inMoney(to, money);
            }
        });
    }

第二种 - Spring的声明式事务AOP（XML的方式）

1)配置事务管理器

<bean  id="transactionManager" class="org.springframework.jdbc.datasource.DataSourceTransactionManager">
		<property name="dataSource" ref="dataSource"/>
</bean>

2)配置事务通知

<!-- 配置事务的增强 -->
<tx:advice id="txAdvice" transaction-manager="transactionManager">
<tx:attributes>
		<!-- isolation="DEFAULT" 隔离级别
		     propagation="REQUIRED" 传播行为
		     read-only="false"  只读
		     timeout="-1"  过期时间
		     rollback-for="" -Exception
		     no-rollback-for="" +Exception
		-->
		<tx:method name="transfer" propagation="REQUIRED"/>
</tx:attributes>
</tx:advice>

3)配置AOP事务

<aop:config>
	<aop:pointcut  expression="execution(*cn.itcast.transaction.demo2.AccountServiceImpl.transfer(..))" id="pointcut1"/>
	<aop:advisor advice-ref="txAdvice" pointcut-ref="pointcut1"/>
</aop:config>

第二种 - Spring的声明式事务AOP（注解的方式）

1)配置事务管理器

<bean  id="transactionManager" class="org.springframework.jdbc.datasource.DataSourceTransactionManager">
		<property name="dataSource" ref="dataSource"/>
</bean>

2)开启事务管理的注解

<tx:annotation-driven transaction-manager="transactionManager"/>

3)在使用事务的类上添加一个注解：@Transactional