public interface BookShopDao {

    /**
     * 根据书号查询书的价格
     */

    Book findBookPriceByIsbn(String isbn);

    /**
     * 根据书号查询书的价格
     * @param isbn
     * @param stock
     * @return
     */
    int updateBookStock(String isbn);

    /**
     * 根据书号查询书的价格
     * @param username
     * @param balance
     * @return
     */
    int updateAccount(String username, Integer price);
}

@Repository
public class BookShopDaoImpl implements BookShopDao {

    @Autowired
    private JdbcTemplate template;

    @Override
    public Book findBookPriceByIsbn(String isbn) {
        String sql = "SELECT * FROM book WHERE isbn=?";
        RowMapper<Book> rowMapper = new BeanPropertyRowMapper<>(Book.class);
        return template.queryForObject(sql, rowMapper, isbn);
    }

    @Override
    public int updateBookStock(String isbn) {
        //判断库存是否足够
        String sql = "SELECT stock from book_stock WHERE isbn = ?";
        Integer bookCount = template.queryForObject(sql, Integer.class, isbn);
        if (bookCount <= 0) {
            throw new RuntimeException("库存不足，没有书了");
        }
        sql = "UPDATE book_stock SET stock = stock-1 WHERE isbn = ?";
        return template.update(sql, isbn);
    }

    @Override
    public int updateAccount(String username, Integer price) {
        //判断余额是否足够
        String sql = "SELECT balance from account WHERE username = ?";
        Integer balance = template.queryForObject(sql, Integer.class, username);
        if (balance <= price) {
            throw new RuntimeException("余额不足");
        }
        sql = "UPDATE account  SET balance  = balance - ? WHERE username = ?";
        return template.update(sql, price, username);
    }
}

public interface BookShopService {

    Book buyBook(String isbn, String username);
}

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


    @Autowired
    private BookShopDao bookShopDao;

    /**
     * 买书 :账户余额减少，库存减少
     * @param isbn
     * @param username
     * @param stock
     * @param balance
     * @return
     */
    @Transactional
    @Override
    public Book buyBook(String isbn, String username) {
        //根据书号查询书的价格
        Book book  = bookShopDao.findBookPriceByIsbn(isbn);
        String  price = book.getPrice();
        //判断库存是否足够
        int updateBookStockResult = bookShopDao.updateBookStock(isbn);
        //判断余额是否足够
        int updateAccountResult =  bookShopDao.updateAccount(username,Integer.valueOf(price));
        return book;
    }
}

　　　<!--包扫描-->
    <context:component-scan base-package="com.jdy.spring2020.scan"/>
    <!--引入外部配置文件-->
    <context:property-placeholder location="classpath:jdbc.properties"/>
    <!-- 一、数据源-->
    <bean id="dataSource" class="com.mchange.v2.c3p0.ComboPooledDataSource">
        <property name="jdbcUrl" value="${jdbc.jdbcUrl}"/>
        <property name="driverClass" value="${jdbc.driverClass}"/>
        <property name="user" value="${jdbc.user}"/>
        <property name="password" value="${jdbc.password}"/>
    </bean>

    <!--二、JDBC模板-->
    <bean id="template" class="org.springframework.jdbc.core.JdbcTemplate">
        <property name="dataSource" ref="dataSource"/>
    </bean>

    <!-- 三、配置事务管理器 -->
    <bean id="transactionManager" class="org.springframework.jdbc.datasource.DataSourceTransactionManager">
        <property name="dataSource" ref="dataSource"/>
    </bean>

    <!-- 四、启用事务注解 transaction-manager:用来指定事务管理器，如果事务管理器的id值时transaction-manager，可以省略不进行指定 -->
    <tx:annotation-driven transaction-manager="transactionManager" proxy-target-class="true"/>

public class TX_Test {
    private BookShopDao bookShopDao;
    private BookShopService bookShopService;

    {
        ApplicationContext context = new ClassPathXmlApplicationContext("application_tx.xml");
        bookShopService= context.getBean("bookShopServiceImpl", BookShopServiceImpl.class);
        bookShopDao= context.getBean("bookShopDaoImpl", BookShopDaoImpl.class);
    }

    /**
     * 买书
     */
    @Test
    public void test_method01() {
        bookShopService.buyBook("ISBN-001","Jerry");
    }
}

@Service("cashierimpl")
public class Cashierimpl implements Cashier  {

    @Autowired
    private BookShopService bookShopService;
　　　
　　
　　 //结账操作，买了多本书，账户余额只够买一本
    @Transactional
    @Override
    public void checkOut(List<String> isbns, String username) {
        for (String isbn : isbns) {
            Book book  = bookShopService.buyBook(isbn,username);
        }
    }
}

public interface Cashier {
    /**
     * 收银台结算
     * @param isbns
     * @param username
     */
    void checkOut(List<String> isbns, String username);
}

@Service("cashierimpl")
public class Cashierimpl implements Cashier  {

    @Autowired
    private BookShopService bookShopService;

    @Override
    @Transactional(propagation = Propagation.REQUIRES_NEW)
    public void checkOut(List<String> isbns, String username) {
        for (String isbn : isbns) {
            Book book  = bookShopService.buyBook(isbn,username);
        }
    }
} 

public class Cashierimpl implements Cashier  {

    @Autowired
    private BookShopService bookShopService;

    @Override
    @Transactional(propagation = Propagation.REQUIRES_NEW ,isolation= Isolation.READ_COMMITTED)
    public void checkOut(List<String> isbns, String username) {
        for (String isbn : isbns) {
            Book book  = bookShopService.buyBook(isbn,username);
        }
    }
}

public class Cashierimpl implements Cashier  {

    @Autowired
    private BookShopService bookShopService;

    @Override
    @Transactional(propagation = Propagation.REQUIRES_NEW ,isolation= Isolation.READ_COMMITTED,
            rollbackFor = {IOException.class, SQLException.class},
            noRollbackFor= {NullPointerException.class}
            )
    public void checkOut(List<String> isbns, String username) {
        for (String isbn : isbns) {
            Book book  = bookShopService.buyBook(isbn,username);
        }
    }
}

public class Cashierimpl implements Cashier  {

    @Autowired
    private BookShopService bookShopService;

    @Override
    @Transactional(propagation = Propagation.REQUIRES_NEW ,isolation= Isolation.READ_COMMITTED,
            rollbackFor = {IOException.class, SQLException.class},
            noRollbackFor= {NullPointerException.class},
            readOnly = true,
            timeout = 30
            )
    public void checkOut(List<String> isbns, String username) {
        for (String isbn : isbns) {
            Book book  = bookShopService.buyBook(isbn,username);
        }
    }
}

　　<!-- 配置事务切面 -->
    <aop:config>
        <aop:pointcut 
            expression="execution(* com.atguigu.tx.component.service.BookShopServiceImpl.purchase(..))" 
            id="txPointCut"/>
        <!-- 将切入点表达式和事务属性配置关联到一起 -->
        <aop:advisor advice-ref="myTx" pointcut-ref="txPointCut"/>
    </aop:config>
    
    <!-- 配置基于XML的声明式事务  -->
    <tx:advice id="myTx" transaction-manager="transactionManager">
        <tx:attributes>
            <!-- 设置具体方法的事务属性 -->
            <tx:method name="find*" read-only="true"/>
            <tx:method name="get*" read-only="true"/>
            <tx:method name="purchase" 
                isolation="READ_COMMITTED" 
    　　　　　　　no-rollback-for="java.lang.ArithmeticException,java.lang.NullPointerException"
                propagation="REQUIRES_NEW"
                read-only="false"
                timeout="10"/>
        </tx:attributes>
    </tx:advice>