Spring入门初体验（3）----声明式事务（基于注解）

1.首先来建立需要的数据库表

-- ----------------------------
-- Table structure for `account`
-- ----------------------------
DROP TABLE IF EXISTS `account`;
CREATE TABLE `account` (
  `username` varchar(45) NOT NULL DEFAULT '',
  `balance` int(160) DEFAULT NULL,
  PRIMARY KEY (`username`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8;

-- ----------------------------
-- Records of account
-- ----------------------------
INSERT INTO `account` VALUES ('AA', '40');

-- ----------------------------
-- Table structure for `book`
-- ----------------------------
DROP TABLE IF EXISTS `book`;
CREATE TABLE `book` (
  `isbn` int(11) NOT NULL DEFAULT '0',
  `book_name` varchar(45) DEFAULT NULL,
  `price` int(11) DEFAULT NULL,
  PRIMARY KEY (`isbn`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8;

-- ----------------------------
-- Records of book
-- ----------------------------
INSERT INTO `book` VALUES ('1001', 'java', '60');
INSERT INTO `book` VALUES ('1002', 'oracle', '70');

-- ----------------------------
-- Table structure for `book_stock`
-- ----------------------------
DROP TABLE IF EXISTS `book_stock`;
CREATE TABLE `book_stock` (
  `isbn` varchar(45) NOT NULL DEFAULT '',
  `stock` int(11) DEFAULT NULL,
  PRIMARY KEY (`isbn`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8;

-- ----------------------------
-- Records of book_stock
-- ----------------------------
INSERT INTO `book_stock` VALUES ('1001', '1');
INSERT INTO `book_stock` VALUES ('1002', '8');

-- ----------------------------
-- Table structure for `departments`
-- ----------------------------
DROP TABLE IF EXISTS `departments`;
CREATE TABLE `departments` (
  `ID` int(11) NOT NULL DEFAULT '0',
  `DEPT_NAME` varchar(45) DEFAULT NULL,
  PRIMARY KEY (`ID`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8;

-- ----------------------------
-- Records of departments
-- ----------------------------
INSERT INTO `departments` VALUES ('1', '财务部');
INSERT INTO `departments` VALUES ('2', '开发部');
INSERT INTO `departments` VALUES ('3', '人事部');
INSERT INTO `departments` VALUES ('4', '公关部');

-- ----------------------------
-- Table structure for `employees`
-- ----------------------------
DROP TABLE IF EXISTS `employees`;
CREATE TABLE `employees` (
  `ID` int(11) NOT NULL DEFAULT '0',
  `LAST_NAME` varchar(25) DEFAULT NULL,
  `EMAIL` varchar(25) DEFAULT NULL,
  `DEPT_ID` int(11) DEFAULT NULL,
  PRIMARY KEY (`ID`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8;

-- ----------------------------
-- Records of employees
-- ----------------------------
INSERT INTO `employees` VALUES ('0', 'AA', 'aa@@@tain.com', '1');
INSERT INTO `employees` VALUES ('1', 'Tom', '123@qq.com', '1');
INSERT INTO `employees` VALUES ('2', 'tian', '323@qq.com', '2');
INSERT INTO `employees` VALUES ('3', 'Jerry', 'ff@qq.com', '3');
INSERT INTO `employees` VALUES ('4', 'Rose', 'aa@164.com', '3');
INSERT INTO `employees` VALUES ('5', 'tianjun', 'cc@sina.com', '2');
INSERT INTO `employees` VALUES ('6', 'AA', 'aa@@@tain.com', '1');
INSERT INTO `employees` VALUES ('7', 'BB', 'bb@@@tain.com', '2');
INSERT INTO `employees` VALUES ('8', 'CC', 'cc@@@tain.com', '3');
INSERT INTO `employees` VALUES ('9', 'DD', 'dd@@@tain.com', '4');
INSERT INTO `employees` VALUES ('10', 'EE', 'ee@@@tain.com', '5');
INSERT INTO `employees` VALUES ('11', 'FF', '123@qq.com', '2');

配置spring的xml文件如下：主要是配置事务管理器和启动事务管理器。

<?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:context="http://www.springframework.org/schema/context"
	xmlns:tx="http://www.springframework.org/schema/tx"
	xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd
		http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-4.1.xsd
		http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-4.1.xsd">
	<!-- 导入文件资源 -->

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


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


	<bean id="dataSource"
		class="org.springframework.jdbc.datasource.DriverManagerDataSource">
		<property name="driverClassName">
			<value>com.mysql.jdbc.Driver</value>
		</property>
		<property name="url">
			<value>jdbc:mysql://localhost:3306/spring4</value>
		</property>
		<property name="username">
			<value>root</value>
		</property>
		<property name="password">
			<value>123</value>
		</property>
	</bean>

	<!-- 配置JDBCTemplate -->
	<bean id="jdbcTemplate" class="org.springframework.jdbc.core.JdbcTemplate">
		<property name="dataSource" ref="dataSource"></property>
	</bean>


	<!-- 配置 事务管理器 -->
	<bean id="transactionManager"
		class="org.springframework.jdbc.datasource.DataSourceTransactionManager	">
		<property name="dataSource" ref="dataSource"></property>
	</bean>
	
	<!-- 启用事务注解 -->
	<tx:annotation-driven transaction-manager="transactionManager"/>

</beans>

Dao基类和继承类

package com.tian.tx;

public interface BookShopDao {
	
	public int findBookPriceByISBN(String ISBN);
	
	//跟新数的库存，是书号对应的库存减一
	public void updateBookStack(String isbn);
	
	//跟新用户的账户余额：username的(balance-price)
	public void updateUserAccount(String username,int price);
	
	
}

package com.tian.tx;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.jdbc.core.JdbcTemplate;
import org.springframework.stereotype.Repository;


@Repository("bookShopDao")
public class BookShopDaoImpl implements BookShopDao {
	
	@Autowired
	private JdbcTemplate jdbcTemplate;
	

	@Override
	public int findBookPriceByISBN(String ISBN) {
		String sql = "select price from book where isbn=?";
		return jdbcTemplate.queryForObject(sql, Integer.class, ISBN);
	}

	@Override
	public void updateBookStack(String isbn) {

		String sql2="select stock from book_stock where isbn=?";
		int stock = jdbcTemplate.queryForObject(sql2, Integer.class, isbn);
		if(stock<0){
			throw new BookStockException("库存不足！");
		}
		
		String sql = "update book_stock set stock = stock-1 where isbn = ?";
		jdbcTemplate.update(sql, isbn);
		
	}

	@Override
	public void updateUserAccount(String username, int price) {
		// TODO Auto-generated method stub
		String sql2="select balance from account where username=?";
		int balance = jdbcTemplate.queryForObject(sql2, Integer.class, username);
		if(balance < price){
			throw new UserAccountException("余额不足！");
		}
		
		String sql = "update account set balance = balance -? where username= ?";
		jdbcTemplate.update(sql,price,username);
	}

}

最后就是来是来实现业务逻辑的service类

package com.tian.tx;

public interface BookShopService {

	public void purchase(String username,String isbn);
}

package com.tian.tx;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;
import org.springframework.transaction.annotation.Transactional;

@Service("bookShopService")
public class BookShopServiceImpl implements BookShopService {

	@Autowired
	private BookShopDao bookShopDao;
	
	
	@Transactional
	public void purchase(String username, String isbn) {
		int price = bookShopDao.findBookPriceByISBN(isbn);
		
		bookShopDao.updateBookStack(isbn);
		
		bookShopDao.updateUserAccount(username, price);
	}

}

补充：两个自定义的抛出异常的类：

package com.tian.tx;

public class BookStockException extends RuntimeException {

	public BookStockException() {
		super();
		// TODO Auto-generated constructor stub
	}

	public BookStockException(String message, Throwable cause,
			boolean enableSuppression, boolean writableStackTrace) {
		super(message, cause, enableSuppression, writableStackTrace);
		// TODO Auto-generated constructor stub
	}

	public BookStockException(String message, Throwable cause) {
		super(message, cause);
		// TODO Auto-generated constructor stub
	}

	public BookStockException(String message) {
		super(message);
		// TODO Auto-generated constructor stub
	}

	public BookStockException(Throwable cause) {
		super(cause);
		// TODO Auto-generated constructor stub
	}

}

package com.tian.tx;



public class UserAccountException extends RuntimeException {

	public UserAccountException() {
		super();
		// TODO Auto-generated constructor stub
	}

	public UserAccountException(String message, Throwable cause,
			boolean enableSuppression, boolean writableStackTrace) {
		super(message, cause, enableSuppression, writableStackTrace);
		// TODO Auto-generated constructor stub
	}

	public UserAccountException(String message, Throwable cause) {
		super(message, cause);
		// TODO Auto-generated constructor stub
	}

	public UserAccountException(String message) {
		super(message);
		// TODO Auto-generated constructor stub
	}

	public UserAccountException(Throwable cause) {
		super(cause);
		// TODO Auto-generated constructor stub
	}

}

最后就是测试：

private ApplicationContext ctx =null;
	private BookShopDao bookDao = null;
	
	private BookShopService bs =null;
	{
		ctx = new ClassPathXmlApplicationContext("applicationContext.xml");
		bookDao = ctx.getBean(BookShopDao.class);
		
		bs = ctx.getBean(BookShopService.class);
	}
	
	@Test
	public void test4(){
		bs.purchase("AA", "1001");
	}
	

大家可以上试下如果没有注解@Transaction，执行的结果是，余额会抛出异常，但是库存stock依然会减一，就是东西没卖，库存变了，不合理；加了事务注解后，就会自动回滚了，余额异常，库存不变，符合常识。