步骤：
- 正常配置jdbctemplate
- 正常配置bean
- 配置事物管理器
- 配置事物管理器
- 配置aop切入点,通过切入点把事物链接起来
思路：
接着上一个买书的例子吧，直接拷到新包下，把注解都干掉，需要自动引入的直接set方法
package com.spring.bean; 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); }
package com.spring.bean; import org.springframework.jdbc.core.JdbcTemplate; public class BookShopDaoImpl implements BookShopDao { private JdbcTemplate jdbcTemplate; public void setJdbcTemplate(JdbcTemplate jdbcTemplate) { this.jdbcTemplate = jdbcTemplate; } 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); } }
package com.spring.bean; public interface BookShopService { public void purchase(String username, String isbn); }
package com.spring.bean; public class BookShopServiceImpl implements BookShopService { private BookShopDao bookShopDao; public void setBookShopDao(BookShopDao bookShopDao) { this.bookShopDao = bookShopDao; } @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); } }
package com.spring.bean; import java.util.List; public interface Cashier { public void checkout(String username, List<String> isbns); }
package com.spring.bean; import java.util.List; public class CashierImpl implements Cashier { private BookShopService bookShopService; public void setBookShopService(BookShopService bookShopService) { this.bookShopService = bookShopService; } @Override public void checkout(String username, List<String> isbns) { for(String isbn: isbns){ bookShopService.purchase(username, isbn); } } }
自定义异常不贴了，和上节代码一样
bean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:context="http://www.springframework.org/schema/context" xmlns:tx="http://www.springframework.org/schema/tx" xmlns:aop="http://www.springframework.org/schema/aop" xsi:schemaLocation="http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop-4.0.xsd 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"> <!-- 导入资源文件 --> <context:property-placeholder location="classpath:db.properties"/> <!-- 配置 mysql 数据源 --> <bean id="dataSource" class="org.springframework.jdbc.datasource.DriverManagerDataSource"> <property name="username" value="${jdbc.user}"></property> <property name="password" value="${jdbc.password}"></property> <property name="url" value="${jdbc.jdbcUrl}"></property> <property name="driverClassName" value="${jdbc.driverClass}"></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bean --> <bean id="bookShopDao" class="com.spring.bean.BookShopDaoImpl"> <property name="jdbcTemplate" ref="jdbcTemplate"></property> </bean> <bean id="bookShopService" class="com.spring.bean.BookShopServiceImpl"> <property name="bookShopDao" ref="bookShopDao"></property> </bean> <bean id="cashier" class="com.spring.bean.CashierImpl"> <property name="bookShopService" ref="bookShopService"></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> <!-- 配置事物属性 --> <tx:advice id="txadvice" transaction-manager="transactionManager"> <tx:attributes> <tx:method name="purchase" propagation="REQUIRES_NEW"/> <tx:method name="find*" read-only="true"/> </tx:attributes> </tx:advice> <!-- 配置事物切入点,把事物通过切入点连接起来 --> <aop:config> <aop:pointcut expression="execution(* com.spring.bean.*.*(..))" id="txPointCut"/> <aop:advisor advice-ref="txadvice" pointcut-ref="txPointCut"/> </aop:config> <!-- <aop:config> <aop:pointcut expression=" execution(* com.spring.bean.* . *(..))" id="pointcut"/> <aop:advisor advice-ref="txadvice" pointcut-ref="pointcut"/> </aop:config> --> </beans>
注意，
如果配置文件正确，报错空指针异常，一般是@Autowired的实体，，没用set方法创建实体
报错信息如下：
org.springframework.beans.factory.xml.XmlBeanDefinitionStoreException: Line 15 in XML document from class path resource [beans.xml] is invalid; nested exception is org.xml.sax.SAXParseException; lineNumber: 15; columnNumber: 15; cvc-complex-type.2.4.c: 通配符的匹配很全面, 但无法找到元素 'aop:config' 的声明。
一般是配置文件的顶部没有导入相应的aop schema命名空间，把命名空间加上即可。