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。