spring_声明式事务： @Transactional

例子、

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

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

<tx:annotation-driven transaction-manager="tx" />
<!--3:给事务方法加注解@Transactional

@Service
public class BookService {

@Autowired
private BookDao bookDao;

/**
* 结账；传入哪个用户买了哪本书
* @param username
* @param isbn
*/
@Transactional
public void checkout(String username,String isbn){
//1、减库存
bookDao.updateStock(isbn);

int price = bookDao.getPrice(isbn);
//2、减余额
bookDao.updateBalance(username,price);
}
}