本地事务系列之二：使用PlatformTransactionManager

Spring的事务管理器接口：

public interface PlatformTransactionManager {

	TransactionStatus getTransaction(TransactionDefinition definition) throws TransactionException; // 获取事务状态

	void commit(TransactionStatus status) throws TransactionException; // 提交事务

	void rollback(TransactionStatus status) throws TransactionException; // 回滚事务
}

Spring提供的实现


这里是单数据源，可以使用DataSourceTransactionManager：
FruitShop实现类：

public class TransactionalApiJdbcFruitShop extends JdbcDaoSupport implements FruitShop {
	private PlatformTransactionManager txManager;

	public void setTxManager(PlatformTransactionManager txManager) {
		this.txManager = txManager;
	}

	@Override
	public boolean purchase(int fruitId, String userName, int count) {
		TransactionDefinition definition = new DefaultTransactionDefinition();
		TransactionStatus status = txManager.getTransaction(definition);

		String querySql = "SELECT PRICE FROM FRUIT WHERE ID = ?";
		String upStockSql = "UPDATE FRUIT_STOCK SET STOCK = STOCK - ? WHERE ID = ?";
		String upAccountSql = "UPDATE ACCOUNT SET BALANCE = BALANCE - ? WHERE USERNAME = ?";

		try {
			int price = getJdbcTemplate().queryForInt(querySql, new Object[] { fruitId });
			getJdbcTemplate().update(upStockSql, new Object[] { count, fruitId });
			getJdbcTemplate().update(upAccountSql, new Object[] { price * count, userName });
			txManager.commit(status);
		} catch (DataAccessException e) {
			txManager.rollback(status);
			throw e;
		} catch (TransactionException e) {
			txManager.rollback(status);
			throw e;
		}
		return true;
	}
}

beans-fruitshop.xml文件：

<bean id="dataSource" class="org.springframework.jdbc.datasource.DriverManagerDataSource">
  <property name="driverClassName" value="com.mysql.jdbc.Driver" />
  <property name="url" value="jdbc:mysql://localhost:3306/spring?characterEncoding=utf8" />
  <property name="username" value="spring" />
  <property name="password" value="123456" />
</bean>

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

<bean id="txApiFruitShop" class="com.john.tx.service.impl.TransactionalApiJdbcFruitShop">
  <property name="dataSource" ref="dataSource" /><!--JdbcDaoSupport的子类需要指定dataSource-->
  <property name="txManager" ref="txManager" />
</bean>

测试：

@RunWith(SpringJUnit4ClassRunner.class)
@ContextConfiguration(locations = { "classpath:/beans-fruitshop.xml" })
public class JdbcFruitShopTest {
	@Resource(name = "txApiFruitShop")
	FruitShop txApiFruitShop;

	@Test
	public void txApiTest() {
		int fruitId = 1;
		String userName = "user1";
		int count = 3;
		txApiFruitShop.purchase(fruitId, userName, count);
	}
}