标签:测试 java return query 初学 one pen 方法 cas
spring的事务管理,本文的例子是:比如你需要网购一本书,卖书的那一方有库存量以及书的价格,你有账户余额。回想我们在编程中要实现买书这样的功能,由于你的账户表和书的库存量表肯定不是同一张数据库表,所以必定会有一个先后,要么先将账户余额扣除书的价格,紧接着将书的库存量减一,要么反过来。那么问题来了,假如我们先将你的账户余额减掉,然后发现书的库存不足,这时怎么办呢,这就需要事务了,当我们发现书的库存不足时就要回滚事务,将你的余额返回去。只要配置了事务,发生了异常,就回滚。这就是事务的回滚。注:新人理解,如有错误,望指正,谢谢。
配置文件applicationContext.xml:
1 <?xml version="1.0" encoding="UTF-8"?> 2 <beans xmlns="http://www.springframework.org/schema/beans" 3 xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" 4 xmlns:p="http://www.springframework.org/schema/p" 5 xmlns:context="http://www.springframework.org/schema/context" 6 xmlns:tx="http://www.springframework.org/schema/tx" 7 xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-4.1.xsd 8 http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-4.3.xsd 9 http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-4.3.xsd"> 10 11 <!-- 导入资源文件 --> 12 <context:property-placeholder location="classpath:jdbc.properties"/> 13 14 <!-- 配置c3p0数据源 --> 15 <bean id="dataSource" class="com.mchange.v2.c3p0.ComboPooledDataSource"> 16 <property name="user" value="${user}"></property> 17 <property name="password" value="${password}"></property> 18 <property name="driverClass" value="${driverClass}"></property> 19 <property name="jdbcUrl" value="${jdbcUrl}"></property> 20 21 <property name="initialPoolSize" value="${initPoolSize}"></property> 22 <property name="maxPoolSize" value="${maxPoolSize}"></property> 23 </bean> 24 25 <!-- 配置自动扫描的包 --> 26 <context:component-scan base-package="spring"></context:component-scan> 27 28 <!-- 配置spring 的JdbcTemplate --> 29 <bean id="jdbcTemplate" class="org.springframework.jdbc.core.JdbcTemplate"> 30 <property name="dataSource" ref="dataSource"></property> 31 </bean> 32 33 <!-- 配置事务管理器 --> 34 <bean id="transactionManager" 35 class="org.springframework.jdbc.datasource.DataSourceTransactionManager"> 36 <property name="dataSource" ref="dataSource"></property> 37 </bean> 38 39 <!-- 启用事务注解 --> 40 <tx:annotation-driven transaction-manager="transactionManager"/> 41 42 43 </beans>
配置文件jdbc.propertices:
user=root password=123 driverClass=com.mysql.jdbc.Driver jdbcUrl=jdbc\:mysql\:///spring?encoding\=UFT-8 initPoolSize=5 maxPoolSize=20
BookShopDao.java:
package spring.tx; public interface BookShopDao { public int findBookPriceByIsbn(String isbn); public void updataBookStock(String isbn); public void updataUserAccount(String username,int price); }
BookShopDaoImp.java:
1 package spring.tx; 2 3 import org.springframework.beans.factory.annotation.Autowired; 4 import org.springframework.jdbc.core.JdbcTemplate; 5 import org.springframework.stereotype.Repository; 6 7 @Repository("bookShopDao") 8 public class BookShopDaoImp implements BookShopDao { 9 10 @Autowired 11 private JdbcTemplate jdbcTemplate; 12 13 @Override 14 public int findBookPriceByIsbn(String isbn) { 15 String sql = "select price from book where isbn=?"; 16 return jdbcTemplate.queryForObject(sql, Integer.class, isbn); 17 } 18 19 @Override 20 public void updataBookStock(String isbn) { 21 // 检查书的库存是否不够 22 String sql1 = "select stock from book_stock where isbn=?"; 23 if (jdbcTemplate.queryForObject(sql1, Integer.class, isbn) <= 0) { 24 throw new BookStockException("库存不足"); 25 } 26 String sql = "update book_stock set stock=stock-1 where isbn=?"; 27 jdbcTemplate.update(sql, isbn); 28 } 29 30 @Override 31 public void updataUserAccount(String username, int price) { 32 // 检查余额是否足够 33 String sql1 = "select balance from account where username=?"; 34 if (jdbcTemplate.queryForObject(sql1, Integer.class, username) < price) { 35 throw new UserAccountException("余额不足"); 36 } 37 String sql = "update account set balance = balance - ? where username=?"; 38 jdbcTemplate.update(sql, price, username); 39 } 40 41 }
BookShopService.java:
package spring.tx; public interface BookShopService { public void purchase(String username,String isbn); }
BookShopServiceImpl.java:
1 package spring.tx; 2 3 import org.springframework.beans.factory.annotation.Autowired; 4 import org.springframework.jdbc.core.JdbcTemplate; 5 import org.springframework.stereotype.Repository; 6 7 @Repository("bookShopDao") 8 public class BookShopDaoImp implements BookShopDao { 9 10 @Autowired 11 private JdbcTemplate jdbcTemplate; 12 13 @Override 14 public int findBookPriceByIsbn(String isbn) { 15 String sql = "select price from book where isbn=?"; 16 return jdbcTemplate.queryForObject(sql, Integer.class, isbn); 17 } 18 19 @Override 20 public void updataBookStock(String isbn) { 21 // 检查书的库存是否不够 22 String sql1 = "select stock from book_stock where isbn=?"; 23 if (jdbcTemplate.queryForObject(sql1, Integer.class, isbn) <= 0) { 24 throw new BookStockException("库存不足"); 25 } 26 String sql = "update book_stock set stock=stock-1 where isbn=?"; 27 jdbcTemplate.update(sql, isbn); 28 } 29 30 @Override 31 public void updataUserAccount(String username, int price) { 32 // 检查余额是否足够 33 String sql1 = "select balance from account where username=?"; 34 if (jdbcTemplate.queryForObject(sql1, Integer.class, username) < price) { 35 throw new UserAccountException("余额不足"); 36 } 37 String sql = "update account set balance = balance - ? where username=?"; 38 jdbcTemplate.update(sql, price, username); 39 } 40 41 }
Cashier.java:
package spring.tx; import java.util.List; public interface Cashier { public void checkout(String username,List<String> isbns); }
CashierImpl.java:
1 package spring.tx; 2 3 import java.util.List; 4 5 import org.springframework.beans.factory.annotation.Autowired; 6 import org.springframework.stereotype.Service; 7 import org.springframework.transaction.annotation.Propagation; 8 import org.springframework.transaction.annotation.Transactional; 9 10 @Service("cashier") 11 public class CashierImpl implements Cashier { 12 13 @Autowired 14 private BookShopService bookShopService; 15 16 17 @Transactional 18 @Override 19 public void checkout(String username, List<String> isbns) { 20 for (int i = 0; i < isbns.size(); i++) { 21 bookShopService.purchase(username, isbns.get(i)); 22 } 23 } 24 25 }
定义两个异常类:
1 package spring.tx; 2 3 public class BookStockException extends RuntimeException{ 4 5 /** 6 * 7 */ 8 private static final long serialVersionUID = 1L; 9 10 public BookStockException() { 11 super(); 12 // TODO Auto-generated constructor stub 13 } 14 15 public BookStockException(String message, Throwable cause, boolean enableSuppression, boolean writableStackTrace) { 16 super(message, cause, enableSuppression, writableStackTrace); 17 // TODO Auto-generated constructor stub 18 } 19 20 public BookStockException(String message, Throwable cause) { 21 super(message, cause); 22 // TODO Auto-generated constructor stub 23 } 24 25 public BookStockException(String message) { 26 super(message); 27 // TODO Auto-generated constructor stub 28 } 29 30 public BookStockException(Throwable cause) { 31 super(cause); 32 // TODO Auto-generated constructor stub 33 } 34 35 36 }
package spring.tx; public class UrAccountExceptionse 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 } }
测试方法:
package spring.tx.test; import java.util.ArrayList; import java.util.List; import org.junit.Test; import org.springframework.context.ApplicationContext; import org.springframework.context.support.ClassPathXmlApplicationContext; import spring.tx.BookShopDao; import spring.tx.BookShopService; import spring.tx.Cashier; public class SpringTransactionTest { private ApplicationContext ctx=null; private BookShopDao bookShopDao; private BookShopService bookShopService; private Cashier cashier; { ctx=new ClassPathXmlApplicationContext("applicationContext.xml"); bookShopDao =(BookShopDao) ctx.getBean("bookShopDao"); bookShopService=(BookShopService) ctx.getBean("bookShopService"); cashier =(Cashier) ctx.getBean("cashier"); } @Test public void testTransactionPropagation(){ List<String > isbns=new ArrayList<String>(); isbns.add("1001"); isbns.add("1002"); cashier.checkout("aaa", isbns); } @Test public void testBookShopService() { bookShopService.purchase("aaa", "1001"); } @Test public void testupdataBookStock(){ bookShopDao.updataBookStock("1001"); } @Test public void testUpdataUserAccount(){ bookShopDao.updataUserAccount("aaa", 200); } @Test public void testBookShopDao(){ int price=bookShopDao.findBookPriceByIsbn("1001"); System.out.println(price); } }
标签:测试 java return query 初学 one pen 方法 cas
原文地址:http://www.cnblogs.com/hyyq/p/6705626.html