步驟:
- 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切入點,通過切入點把事物鏈接起來
思路:
接着上一個買書的例子吧,直接拷到新包下,把注解都干掉,需要自動引入的直接set方法
package com.spring.bean; public interface BookShopDao { //根據書號獲取書的單價 public int findBookPriceByIsbn(String isbn); //更新數的庫存. 使書號對應的庫存 - 1 public void updateBookStock(String isbn); //更新用戶的賬戶余額: 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) { //檢查書的庫存是否足夠, 若不夠, 則拋出異常 String sql2 = "SELECT stock FROM book_stock WHERE isbn = ?"; int stock = jdbcTemplate.queryForObject(sql2, Integer.class, isbn); if(stock == 0){ throw new BookStockException("庫存不足!"); } String sql = "UPDATE book_stock SET stock = stock -1 WHERE isbn = ?"; jdbcTemplate.update(sql, isbn); } @Override public void updateUserAccount(String username, int price) { //驗證余額是否足夠, 若不足, 則拋出異常 String sql2 = "SELECT balance FROM account WHERE username = ?"; int balance = jdbcTemplate.queryForObject(sql2, Integer.class, username); if(balance < price){ throw new UserAccountException("余額不足!"); } 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. 獲取書的單價 int price = bookShopDao.findBookPriceByIsbn(isbn); //2. 更新數的庫存 bookShopDao.updateBookStock(isbn); //3. 更新用戶余額 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); } } }
自定義異常不貼了,和上節代碼一樣
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"> <!-- 導入資源文件 --> <context:property-placeholder location="classpath:db.properties"/> <!-- 配置 mysql 數據源 --> <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, 該對象可以使用具名參數, 其沒有無參數的構造器, 所以必須為其構造器指定參數 --> <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> <!-- 配置事務管理器 --> <bean id="transactionManager" class="org.springframework.jdbc.datasource.DataSourceTransactionManager"> <property name="dataSource" ref="dataSource"></property> </bean> <!-- 配置事物屬性 --> <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> <!-- 配置事物切入點,把事物通過切入點連接起來 --> <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,
如果配置文件正確,報錯空指針異常,一般是@Autowired的實體,,沒用set方法創建實體
報錯信息如下:
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, 但無法找到元素 'aop:config' 的聲明。
一般是配置文件的頂部沒有導入相應的aop schema命名空間,把命名空間加上即可。