Spring_事务-注解代码

applicationContext.xml

<?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/tx http://www.springframework.org/schema/tx/spring-tx-4.0.xsd
http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-4.0.xsd">

<context:component-scan base-package="com.atguigu.spring"></context:component-scan>

<!-- 导入资源文件 -->
<context:property-placeholder location="classpath:db.properties"/>

<!-- 配置 C3P0 数据源 -->
<bean id="dataSource"
class="com.mchange.v2.c3p0.ComboPooledDataSource">
<property name="user" value="${jdbc.user}"></property>
<property name="password" value="${jdbc.password}"></property>
<property name="jdbcUrl" value="${jdbc.jdbcUrl}"></property>
<property name="driverClass" value="${jdbc.driverClass}"></property>

<property name="initialPoolSize" value="${jdbc.initPoolSize}"></property>
<property name="maxPoolSize" value="${jdbc.maxPoolSize}"></property>
</bean>

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

<!-- 配置 NamedParameterJdbcTemplate, 该对象可以使用具名参数, 其没有无参数的构造器, 所以必须为其构造器指定参数 -->
<bean id="namedParameterJdbcTemplate"
class="org.springframework.jdbc.core.namedparam.NamedParameterJdbcTemplate">
<constructor-arg ref="dataSource"></constructor-arg>
</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>

BookShopDao.JAVA

package com.atguigu.spring.tx;

public interface BookShopDao {

//根据书号获取书的单价
public int findBookPriceByIsbn(String isbn);

//更新数的库存. 使书号对应的库存 - 1
public void updateBookStock(String isbn);

//更新用户的账户余额: 使 username 的 balance - price
public void updateUserAccount(String username, int price);
}

BookShopDaoImpl.JAVA

package com.atguigu.spring.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 updateBookStock(String isbn) {
//检查书的库存是否足够, 若不够, 则抛出异常
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) {
//验证余额是否足够, 若不足, 则抛出异常
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);
}

}

BookShopService.JAVA

package com.atguigu.spring.tx;

public interface BookShopService {

public void purchase(String username, String isbn);

}

BookShopServiceImpl.JAVA

package com.atguigu.spring.tx;

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

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

@Autowired
private BookShopDao bookShopDao;

//添加事务注解
//1.使用 propagation 指定事务的传播行为, 即当前的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: 事务自己的事务, 调用的事务方法的事务被挂起.
//2.使用 isolation 指定事务的隔离级别, 最常用的取值为 READ_COMMITTED
//3.默认情况下 Spring 的声明式事务对所有的运行时异常进行回滚. 也可以通过对应的
//属性进行设置. 通常情况下去默认值即可.
//4.使用 readOnly 指定事务是否为只读. 表示这个事务只读取数据但不更新数据,
//这样可以帮助数据库引擎优化事务. 若真的事一个只读取数据库值的方法, 应设置 readOnly=true
//5.使用 timeout 指定强制回滚之前事务可以占用的时间.
// @Transactional(propagation=Propagation.REQUIRES_NEW,
// isolation=Isolation.READ_COMMITTED,
// noRollbackFor={UserAccountException.class})
@Transactional(propagation=Propagation.REQUIRES_NEW,
isolation=Isolation.READ_COMMITTED,
readOnly=false,
timeout=3)
@Override
public void purchase(String username, String isbn) {

try {
Thread.sleep(5000);
} catch (InterruptedException e) {}

//1. 获取书的单价
int price = bookShopDao.findBookPriceByIsbn(isbn);

//2. 更新数的库存
bookShopDao.updateBookStock(isbn);

//3. 更新用户余额
bookShopDao.updateUserAccount(username, price);
}

}

Cashier.JAVA

package com.atguigu.spring.tx;

import java.util.List;

public interface Cashier {

public void checkout(String username, List<String> isbns);

}

CashierImpl.JAVA

package com.atguigu.spring.tx;

import java.util.List;

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

@Service("cashier")
public class CashierImpl implements Cashier {

@Autowired
private BookShopService bookShopService;

@Transactional
@Override
public void checkout(String username, List<String> isbns) {
for(String isbn: isbns){
bookShopService.purchase(username, isbn);
}
}

}

BookStockException.JAVA

package com.atguigu.spring.tx;

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
}

}

UserAccountException.JAVA

package com.atguigu.spring.tx;

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
}

}

SpringTransactionTest.JAVA

package com.atguigu.spring.tx;

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 {

private ApplicationContext ctx = null;
private BookShopDao bookShopDao = null;
private BookShopService bookShopService = null;
private Cashier cashier = null;

{
ctx = new ClassPathXmlApplicationContext("applicationContext.xml");
bookShopDao = ctx.getBean(BookShopDao.class);
bookShopService = ctx.getBean(BookShopService.class);
cashier = ctx.getBean(Cashier.class);
}

@Test
public void testTransactionlPropagation(){
cashier.checkout("AA", Arrays.asList("1001", "1002"));
}

@Test
public void testBookShopService(){
bookShopService.purchase("AA", "1001");
}

@Test
public void testBookShopDaoUpdateUserAccount(){
bookShopDao.updateUserAccount("AA", 200);
}

@Test
public void testBookShopDaoUpdateBookStock(){
bookShopDao.updateBookStock("1001");
}

@Test
public void testBookShopDaoFindPriceByIsbn() {
System.out.println(bookShopDao.findBookPriceByIsbn("1001"));
}

}