Spring（六）spring之事務管理

通過給賬戶贈送積分的例子引入事務的話題：

未使用事務：

賬戶加減積分Dao：

public interface AccountDao {
	void upScore(int score,int id);
	void downScore(int score,int id);
}

賬戶加減積分實現類：

public class AccountDaoImpl extends JdbcDaoSupport implements AccountDao {

	@Override
	public void upScore(int score, int id) {
		getJdbcTemplate().update("update t_user set score = score + ? where id = ?", score,id);
	}

	@Override
	public void downScore(int score, int id) {
		getJdbcTemplate().update("update t_user set score = score - ? where id = ?", score,id);
	}
}

賬戶贈送積分Service：

public interface AccountService {
	void sendScore(int senderId,int accepterId,int score);
}

賬戶贈送積分實現類：

public class AccountServiceImpl implements AccountService {

	private AccountDao accountDao;
	
	@Override
	public void sendScore(int senderId, int accepterId, int score) {
		accountDao.downScore(score, senderId);
		accountDao.upScore(score, accepterId);
	}

	public AccountDao getAccountDao() {
		return accountDao;
	}

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

spring的配置文件：

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
	xmlns="http://www.springframework.org/schema/beans" xmlns:context="http://www.springframework.org/schema/context"
	xmlns:aop="http://www.springframework.org/schema/aop"
	xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-4.2.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-4.2.xsd http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop-4.2.xsd ">

	<context:property-placeholder location="classpath:db.properties" />

	<bean name="dataSource" class="com.mchange.v2.c3p0.ComboPooledDataSource">
		<property name="jdbcUrl" value="${jdbc.jdbcUrl}"></property>
		<property name="driverClass" value="${jdbc.driverClass}"></property>
		<property name="user" value="${jdbc.user}"></property>
		<property name="password" value="${jdbc.password}"></property>
	</bean>

	<bean name="accountDao" class="com.milan.transaction.AccountDaoImpl">
		<property name="dataSource" ref="dataSource"></property>
	</bean>
	
	<bean name="accountService" class="com.milan.transaction.AccountServiceImpl"> 
		<property name="accountDao" ref="accountDao"></property>
	</bean>
	
</beans>	

測試類：

@RunWith(SpringJUnit4ClassRunner.class)
@ContextConfiguration("classpath:applicationContext-transaction.xml")
public class TestDemo {

	@Resource(name="accountService")
	private AccountService service;
	
	@Test
	public void test(){
		service.sendScore(3, 4, 100);
	}
	
}

說明：測試id爲3的賬戶給id爲4的賬戶充值100積分，測試通過。（圖略）

若sendScore方法過程報錯，則會造成只減積分，沒加積分的情況，故此添加spring事務處理

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注意：以上代碼沒有添加事務
==========================================================

spring事務實現方式（一）

spring配置文件中添加：事務核心管理器，事務模板對象

	<!-- 事務核心管理器，依賴於連接池 -->
	<bean name="transactionManager" class="org.springframework.jdbc.datasource.DataSourceTransactionManager">
		<property name="dataSource" ref="dataSource"></property>
	</bean>
	<!-- 事務模板對象 -->
	<bean name="transactionTemplate" class="org.springframework.transaction.support.TransactionTemplate">
		<property name="transactionManager" ref="transactionManager"></property>
	</bean>

將賬戶Service實現類的sendScore方法添加事務處理：

public class AccountServiceImpl implements AccountService {

	private AccountDao accountDao;
	
	private TransactionTemplate template;
	
	@Override
	public void sendScore(int senderId, int accepterId, int score) {
		template.execute(new TransactionCallbackWithoutResult() {
			@Override
			protected void doInTransactionWithoutResult(TransactionStatus arg0) {
				accountDao.downScore(score, senderId);
				int i = 1/0;
				accountDao.upScore(score, accepterId);
			}
		});
	}

	public AccountDao getAccountDao() {
		return accountDao;
	}

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

	public TransactionTemplate getTemplate() {
		return template;
	}

	public void setTemplate(TransactionTemplate template) {
		this.template = template;
	}
}

spring事務實現方式（二）

spring配置文件：

	<!-- 事務核心管理器，依賴於連接池 -->
	<bean name="transactionManager" class="org.springframework.jdbc.datasource.DataSourceTransactionManager">
		<property name="dataSource" ref="dataSource"></property>
	</bean>
	<!-- 事務模板對象 -->
	<bean name="transactionTemplate" class="org.springframework.transaction.support.TransactionTemplate">
		<property name="transactionManager" ref="transactionManager"></property>
	</bean>

	<!-- 配置事務通知 -->
	<tx:advice id="txAdvice" transaction-manager="transactionManager">
		<tx:attributes>
			<!--
			 	isolation:隔離級別
			 	propagation:傳播行爲
			 	read-only:是否只讀
			 -->
			<tx:method name="sendScoreByXml" isolation="REPEATABLE_READ" propagation="REQUIRED" read-only="false" />
			
			<!-- 可以使用通配符*進行批量配置 -->
			<tx:method name="add*" isolation="REPEATABLE_READ" propagation="REQUIRED" read-only="false" />
			<tx:method name="delete*" isolation="REPEATABLE_READ" propagation="REQUIRED" read-only="false" />
			<tx:method name="update*" isolation="REPEATABLE_READ" propagation="REQUIRED" read-only="false" />
			<tx:method name="find*" isolation="REPEATABLE_READ" propagation="REQUIRED" read-only="true" />
		
		</tx:attributes>
	</tx:advice>
	
	<!-- 配置織入 -->
	<aop:config>
		<aop:pointcut expression="execution(* com.milan.transaction.*ServiceImpl.*(..))" id="txPc"/>
		<aop:advisor advice-ref="txAdvice" pointcut-ref="txPc" />
	</aop:config>

spring事務實現方式（三）

使用註解管理：

spring配置文件：

	<!-- 開啓使用註解管理事務 -->
	<!-- <tx:annotation-driven/> -->

Service實現類中添加@Transactional註解

	@Override
	@Transactional(isolation=Isolation.REPEATABLE_READ,propagation=Propagation.REQUIRED,readOnly=false)
	public void sendScoreByHere(int senderId, int accepterId, int score) {
		accountDao.downScore(score, senderId);
		//int i = 1/0;
		accountDao.upScore(score, accepterId);
	}