Spring入门第二十八课

Posted 2020-09-20 alittlecomputer

事务的传播行为

当事务方法被另一个事务方法调用时，必须指定事务应该如何传播，例如：方法可能继续在现有事务中运行，也可能开启一个新的事务，并在自己的事务中运行。

事务的传播行为可以由传播属性指定.Spring定义了7中类型的传播行为。

 

默认的传播行为是REQUIRED

直接看代码：

db.properties

jdbc.user=root
jdbc.password=logan123
jdbc.driverClass=com.mysql.jdbc.Driver
jdbc.jdbcUrl=jdbc:mysql://localhost:3306/spring

jdbc.initPoolSize=5
jdbc.maxPoolSize=10

<?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/context http://www.springframework.org/schema/context/spring-context-4.3.xsd
        http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-4.3.xsd">

    <context:component-scan base-package="logan.study.spring.tx"></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Spring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>

package logan.study.spring.tx;

public class UserAccountException extends RuntimeException{

    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
    }
    
    

}

package logan.study.spring.tx;

public class BookStockException extends RuntimeException{

    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
    }
    
    

}

package logan.study.spring.tx;

public interface BookShopService {
    
    public void purchase(String username, String isbn);

}

package logan.study.spring.tx;

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

@Service("bookShopService")
public class BookShopServiceImpl implements BookShopService {
    
    @Autowired
    private BookShopDao bookShopDao;

    //添加事务注解
    @Transactional
    @Override
    public void purchase(String username, String isbn) {
        // TODO Auto-generated method stub
        //1.获取书的单价
        int price = bookShopDao.findBookPriceIsbn(isbn);
        //2.更新书的库存
        bookShopDao.updateBookStock(isbn);
        //3.更新用户余额
        bookShopDao.updateUserAccount(username, price);
        

    }

}

package logan.study.spring.tx;

import java.util.List;

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

}

package logan.study.spring.tx;

import java.util.List;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;
import org.springframework.transaction.annotation.Propagation;
import org.springframework.transaction.annotation.Transactional;
@Service("cashier")
public class CashierImpl implements Cashier{
    
    @Autowired
    private BookShopService bookShopService;

    
    /**
     * 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，调用事务方法的事务被挂起
     */ 
    @Transactional(propagation=Propagation.REQUIRES_NEW)
    @Override
    public void checkout(String username, List<String> isbns) {
        // TODO Auto-generated method stub
        for(String isbn:isbns){
            bookShopService.purchase(username, isbn);
        }
        
    }

}

package logan.study.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;
import org.springframework.jdbc.core.JdbcTemplate;

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 testTransactionalPropagation(){
        cashier.checkout("AA", Arrays.asList("1001","1002"));
    }
    
    @Test
    public void testBookShopService(){
        bookShopService.purchase("AA", "1001");
    }
    
    
    @Test
    public void testBookShopDaoUpdateUserAcount(){
        bookShopDao.updateUserAccount("AA", 100);
    }
    
    @Test
    public void testBookShopDaoUpdateBookStock(){
        bookShopDao.updateBookStock("1001");
    }
    
    @Test
    public void testBookShopDaoFindPriceByIsbn(){
        System.out.println(bookShopDao.findBookPriceIsbn("1001"));
    }

    @Test
    public void test() {
        fail("Not yet implemented");
    }

}