spring学习-4-事务

spring声明式事务：

编写接口

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{@Autowiredprivate BookShopDao bookShopDao;//添加事务注解@Transactional@Overridepublic void purchase(String username, String isbn) {//获取书的单价int price=bookShopDao.findBookPriceByIsbn(isbn);//更新书的库存bookShopDao.updateBookStock(isbn);//更新用户余额bookShopDao.updateUserAccount(username, price);}}

public interface BookShopDao {//根据书号查询价格public int findBookPriceByIsbn(String isbn);//更新图书库存public void updateBookStock(String isbn);//更新用户余额public void updateUserAccount(String username,int price);}

接口实现类

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 {@Autowiredprivate JdbcTemplate jdbcTemplate;@Overridepublic int findBookPriceByIsbn(String isbn) {String sql="select price from book where isbn=?";return jdbcTemplate.queryForObject(sql, Integer.class,isbn);}@Overridepublic void updateBookStock(String isbn) {String sql2="select stock from book_stock where isbn=?";Integer 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);}@Overridepublic void updateUserAccount(String username, int price) {String sql2="select balance from account where username=?";Integer 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);}}

异常处理方法

public class BookStockException extends RuntimeException{/** *  */private static final long serialVersionUID = 1L;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}}

public class UserAccountException extends RuntimeException{/** *  */private static final long serialVersionUID = 1L;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}}

配置文件

<?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:aop="http://www.springframework.org/schema/aop"xmlns:context="http://www.springframework.org/schema/context"xmlns:tx="http://www.springframework.org/schema/tx"xsi:schemaLocation="http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop-4.1.xsdhttp://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsdhttp://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-4.1.xsdhttp://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-4.1.xsd"><context:component-scan base-package="spring.transactionmanager"></context:component-scan><!-- 加载配置文件 --><context:property-placeholder location="classpath:db.properties" /><!-- 数据库连接池 --><bean id="dataSource" class="com.alibaba.druid.pool.DruidDataSource"destroy-method="close"><property name="url" value="${jdbc.url}" /><property name="username" value="${jdbc.username}" /><property name="password" value="${jdbc.password}" /><property name="driverClassName" value="${jdbc.driver}" /><property name="maxActive" value="10" /><property name="minIdle" value="5" /></bean><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>

测试类

import static org.junit.Assert.*;import org.junit.Test;import org.springframework.context.ApplicationContext;import org.springframework.context.support.ClassPathXmlApplicationContext;public class SpringTransactionTest {ApplicationContext ctx=null;BookShopDao bookShopDao=null;BookShopService bookShopService=null;{ctx=new ClassPathXmlApplicationContext("applicationContext.xml");bookShopDao=ctx.getBean(BookShopDao.class);bookShopService=ctx.getBean(BookShopService.class);}@Testpublic void testBookShopService(){bookShopService.purchase("AA", "1001");}@Testpublic void testFindBookPriceByIsbn(){System.out.println(bookShopDao.findBookPriceByIsbn("1001"));}@Testpublic void testUpdateBookStock(){bookShopDao.updateBookStock("1001");}@Testpublic void testUpdateUserAccount(){bookShopDao.updateUserAccount("AA", 100);}}

事务的传播行为：

当事务方法被另一个事务方法调用时，必须指明事务方法该如何传播

@Service("bookShopService")public class BookShopServiceImpl implements BookShopService{@Autowiredprivate BookShopDao bookShopDao;//添加事务注解/* * 使用propagation制定事务的传播行为，即当前事务方法被另外一个事务方法调用时，如何使用事务，默认取值为REQUIRED，即使用调用方法的事务 * REQUIRES_NEW表示该方法必须启动一个新事务，并在一个自己的事务内运行，如果有事务在运行，就因该先挂起它 * */@Transactional(propagation=Propagation.REQUIRES_NEW)@Overridepublic void purchase(String username, String isbn) {//获取书的单价int price=bookShopDao.findBookPriceByIsbn(isbn);//更新书的库存bookShopDao.updateBookStock(isbn);//更新用户余额bookShopDao.updateUserAccount(username, price);}}

购买多本书：

import java.util.List;public interface Casher {public void checkout(String username,List<String> isbns);}

import java.util.List;import org.springframework.beans.factory.annotation.Autowired;import org.springframework.stereotype.Service;import org.springframework.transaction.annotation.Transactional;@Service("casher")public class CasherImpl implements Casher{@Autowiredprivate BookShopService bookShopService;@Transactional@Overridepublic void checkout(String username, List<String> isbns) {for (String isbn : isbns) {bookShopService.purchase(username, isbn);}}}

import static org.junit.Assert.*;import java.util.Arrays;import org.junit.Test;import org.springframework.context.ApplicationContext;import org.springframework.context.support.ClassPathXmlApplicationContext;public class SpringTransactionTest {    ApplicationContext ctx=null;    BookShopDao bookShopDao=null;    BookShopService bookShopService=null;    private Casher casher=null;    {        ctx=new ClassPathXmlApplicationContext("applicationContext.xml");        bookShopDao=ctx.getBean(BookShopDao.class);        bookShopService=ctx.getBean(BookShopService.class);        casher=(Casher) ctx.getBean("casher");    }    @Test    public void testTransactionPropagation(){        casher.checkout("AA", Arrays.asList("1001","1002"));    }}