spring aop模式管理数据库事务

1.搭建项目环境，基于idea下maven环境的搭建，此处贴出pom文件的jar包依赖：

<?xml version="1.0" encoding="UTF-8"?>

<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
  xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
  <modelVersion>4.0.0</modelVersion>

  <groupId>com.cyy</groupId>
  <artifactId>spring_aop</artifactId>
  <version>1.0-SNAPSHOT</version>

  <name>spring_aop</name>
  <!-- FIXME change it to the project's website -->
  <url>http://www.example.com</url>

  <properties>
    <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
    <maven.compiler.source>1.8</maven.compiler.source>
    <maven.compiler.target>1.8</maven.compiler.target>
    <spring.version>4.3.12.RELEASE</spring.version>
  </properties>

  <dependencies>
    <dependency>
      <groupId>junit</groupId>
      <artifactId>junit</artifactId>
      <version>4.11</version>
      <scope>test</scope>
    </dependency>

    <dependency>
      <groupId>org.springframework</groupId>
      <artifactId>spring-aop</artifactId>
      <version>${spring.version}</version>
    </dependency>

    <dependency>
      <groupId>aopalliance</groupId>
      <artifactId>aopalliance</artifactId>
      <version>1.0</version>
    </dependency>

    <dependency>
      <groupId>org.aspectj</groupId>
      <artifactId>aspectjrt</artifactId>
      <version>1.8.11</version>
    </dependency>

    <dependency>
      <groupId>org.springframework</groupId>
      <artifactId>spring-aspects</artifactId>
      <version>${spring.version}</version>
    </dependency>

    <dependency>
      <groupId>org.springframework</groupId>
      <artifactId>spring-tx</artifactId>
      <version>${spring.version}</version>
    </dependency>

    <dependency>
      <groupId>org.springframework</groupId>
      <artifactId>spring-jdbc</artifactId>
      <version>${spring.version}</version>
    </dependency>

    <dependency>
      <groupId>mysql</groupId>
      <artifactId>mysql-connector-java</artifactId>
      <version>5.1.42</version>
    </dependency>

    <dependency>
      <groupId>c3p0</groupId>
      <artifactId>c3p0</artifactId>
      <version>0.9.1.2</version>
    </dependency>

    <dependency>
      <groupId>org.springframework</groupId>
      <artifactId>spring-beans</artifactId>
      <version>${spring.version}</version>
    </dependency>

    <dependency>
      <groupId>org.springframework</groupId>
      <artifactId>spring-core</artifactId>
      <version>${spring.version}</version>
    </dependency>

    <dependency>
      <groupId>org.springframework</groupId>
      <artifactId>spring-context</artifactId>
      <version>${spring.version}</version>
    </dependency>

    <dependency>
      <groupId>org.springframework</groupId>
      <artifactId>spring-expression</artifactId>
      <version>${spring.version}</version>
    </dependency>


  </dependencies>

  <build>
    <pluginManagement><!-- lock down plugins versions to avoid using Maven defaults (may be moved to parent pom) -->
      <plugins>
        <plugin>
          <artifactId>maven-clean-plugin</artifactId>
          <version>3.0.0</version>
        </plugin>
        <!-- see http://maven.apache.org/ref/current/maven-core/default-bindings.html#Plugin_bindings_for_jar_packaging -->
        <plugin>
          <artifactId>maven-resources-plugin</artifactId>
          <version>3.0.2</version>
        </plugin>
        <plugin>
          <artifactId>maven-compiler-plugin</artifactId>
          <version>3.7.0</version>
        </plugin>
        <plugin>
          <artifactId>maven-surefire-plugin</artifactId>
          <version>2.20.1</version>
        </plugin>
        <plugin>
          <artifactId>maven-jar-plugin</artifactId>
          <version>3.0.2</version>
        </plugin>
        <plugin>
          <artifactId>maven-install-plugin</artifactId>
          <version>2.5.2</version>
        </plugin>
        <plugin>
          <artifactId>maven-deploy-plugin</artifactId>
          <version>2.8.2</version>
        </plugin>
      </plugins>
    </pluginManagement>
  </build>
</project>

具体的搭建项目步骤，自行百度解决。

2.转账事务环境搭建：

1）创建表和各个类与接口：

    create database ee19_spring_day03;
    use ee19_spring_day03;
    create table account(
      id int primary key auto_increment,
      username varchar(50),
      money int
    );
    insert into account(username,money) values('jack','10000');
    insert into account(username,money) values('rose','10000');

• 新建service层和dao层以及各自下面的impl层

• 在dao下面新建AccountDao接口，代码如下：

    package com.cyy.dao;
  
    /**
     * @Author: Cyy
     * @Description:
     * @Date:Created in 22:37 2018/8/1
     */
    public interface AccountDao {
    
        public void out(String outer, Integer money) ;
        public void in(String inner, Integer money) ;
    
    }
  

• 在dao下的impl下新建实现类AccountDaoImpl，继承自JdbcDaoSupport，实现其中的方法：

    package com.cyy.dao.impl;
    
    import com.cyy.dao.AccountDao;
    import org.springframework.jdbc.core.support.JdbcDaoSupport;
    
    /**
     * @Author: Cyy
     * @Description:
     * @Date:Created in 22:37 2018/8/1
     */
    public class AccountDaoImpl extends JdbcDaoSupport implements AccountDao {
        @Override
        public void out(String outer, Integer money) {
    
            this.getJdbcTemplate().update("update account set money = money - ? where username = ?", money,outer);
        }
    
        @Override
        public void in(String inner, Integer money) {
            this.getJdbcTemplate().update("update account set money = money + ? where username = ?", money,inner);
        }
    }
  

• 新建service下AccountService接口：

    package com.cyy.service;
    
    /**
     * @Author: Cyy
     * @Description:
     * @Date:Created in 22:40 2018/8/1
     */
    public interface AccountService {
    
        public void transfer(String outer, String inner, Integer money);
    }
  

• 新建service.impl下AccountServiceImpl实现类：

    package com.cyy.service.impl;
    
    import com.cyy.dao.AccountDao;
    import com.cyy.service.AccountService;
    import org.springframework.beans.factory.annotation.Autowired;
    import org.springframework.beans.factory.annotation.Qualifier;
    
    /**
     * @Author: Cyy
     * @Description:
     * @Date:Created in 22:40 2018/8/1
     */
    public class AccountServiceImpl  implements AccountService{
    
    
        public void setAccountDao(AccountDao accountDao) {
            this.accountDao = accountDao;
        }
    
        private AccountDao accountDao;
    
    
        @Override
        public void transfer(String outer, String inner, Integer money) {
            // TODO Auto-generated method stub
            accountDao.out(outer, money);
            //断电
    //        int i = 1 / 0;
            accountDao.in(inner, money);
        }
    }
  

2）完善配置文件

• 在main下新建与java的同级目录resources，并且标记为Resources Root;
• 在resources下新建spring上下文文件applicationContext.xml，配置初始配置内容如下：

<?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:aop="http://www.springframework.org/schema/aop"
       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-3.1.xsd
        http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-3.1.xsd
        http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-3.1.xsd
       http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop-3.1.xsd">
    <context:property-placeholder location="classpath:jdbc.properties"/>

    <bean id="dataSource" class="com.mchange.v2.c3p0.ComboPooledDataSource">
        <property name="driverClass" value="${jdbc.driver}"/>
        <property name="jdbcUrl" value="${jdbc.url}"/>
        <property name="user" value="${jdbc.username}"/>
        <property name="password" value="${jdbc.password}"/>
    </bean>
    
    <bean id="accountDao" class="com.cyy.dao.impl.AccountDaoImpl">
        <property name="dataSource" ref="dataSource"/>
    </bean>
    
    <bean id="accountService" class="com.cyy.service.impl.AccountServiceImpl">
        <property name="accountDao" ref="accountDao"/>
    </bean>
    
</beans>

• 在resources下新建jdbc.properties配置文件：

jdbc.driver=com.mysql.jdbc.Driver
jdbc.url=jdbc:mysql://localhost:3306/ee19_spring_day03
jdbc.username=root
jdbc.password=

3）测试文件的配置

• 在main同级的test文件下的java下新建test文件（其实已经maven自动生成了），如图：

  
  image.png

配置代码：

package com.cyy;


import com.cyy.service.AccountService;
import org.junit.Test;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;

/**
 * Unit test for simple App.
 */
public class AppTest 
{
    /**
     * Rigorous Test :-)
     */
    @Test
    public void demo01(){
        String xmlPath = "applicationContext.xml";
        ApplicationContext applicationContext = new ClassPathXmlApplicationContext(xmlPath);
        AccountService accountService =  (AccountService) applicationContext.getBean("accountService");
        accountService.transfer("rose", "jack", 1000);
    }

}

3.测试运行

原本数据库jack和rose的money都是10000的：

image.png

此处在AccountServiceImpl暂时注销掉了
// int i = 1 / 0;
先保证事务的正确运行查看效果，点击运行AppTest类：

image.png

测试通过，再来查看数据库：

image.png

已经成功实现了转账1000块的功能，这次把 // int i = 1 / 0;注释去掉，
并且恢复数据库原本数值，再次点击AppTest类运行：

image.png

异常报错，再去查看数据库：

image.png

事务没有正确回滚，导致事务的ACID特性被破坏，所以接下来，我们将通过几种方式实现事务的管理。

4.手动事务管理

• 修改AccountService接口：

package com.cyy.service;

/**
 * @Author: Cyy
 * @Description:
 * @Date:Created in 22:40 2018/8/1
 */
public interface AccountService {

//    public void transfer(String outer, String inner, Integer money);
    public void transfer(final String outer,final String inner,final Integer money);
}

• 将AccountServiceImpl中原来的transfer注释掉，添加以下代码：

    private TransactionTemplate transactionTemplate;
    public void setTransactionTemplate(TransactionTemplate transactionTemplate) {
        this.transactionTemplate = transactionTemplate;
    }
    @Override
    public void transfer(final String outer,final String inner,final Integer money) {
        transactionTemplate.execute(new TransactionCallbackWithoutResult() {

            @Override
            protected void doInTransactionWithoutResult(TransactionStatus arg0) {
                accountDao.out(outer, money);
                //断电
                int i = 1/0;
                accountDao.in(inner, money);
            }
        });

    }

• 修改applicationContext.xml配置文件：

<bean id="accountService" class="com.cyy.service.impl.AccountServiceImpl">
    <property name="accountDao" ref="accountDao"/>
    <property name="transactionTemplate" ref="transactionTemplate"/>
</bean>
<!-- 手动模式，使用TransactionTemplate -->
 <bean id="txManager" class="org.springframework.jdbc.datasource.DataSourceTransactionManager">
    <property name="dataSource" ref="dataSource"/>
</bean>

<bean id="transactionTemplate" class="org.springframework.transaction.support.TransactionTemplate">
    <property name="transactionManager" ref="txManager"/>
</bean>

• 再次点击AppTest类运行测试，运行结果：

image.png

如期报错,再去查看数据库：

image.png

如期实现了手动的事务管理，通过spring底层使用 TransactionTemplate 事务模板进行操作。

5.代理工厂实现的事务管理

• 修改AccountService接口和AccountServiceImpl类以及applicationContext.xml为原本的配置；

然后新增如下配置：

 <bean id="txManager" class="org.springframework.jdbc.datasource.DataSourceTransactionManager">
   <property name="dataSource" ref="dataSource"/>
 </bean>
    <bean id="proxyAccountService" class="org.springframework.transaction.interceptor.TransactionProxyFactoryBean">
    <property name="proxyInterfaces" value="com.cyy.service.AccountService"/>
    <property name="target" ref="accountService"/>
    <property name="transactionManager" ref="txManager"/>
    <property name="transactionAttributes">
        <props>
            <prop key="transfer">PROPAGATION_REQUIRED,ISOLATION_DEFAULT</prop>
        </props>
    </property>
</bean> 

• 在AppTest中新建demo2方法：

    @Test
    public void demo02(){
        String xmlPath = "applicationContext.xml";
        ApplicationContext applicationContext = new ClassPathXmlApplicationContext(xmlPath);
        AccountService accountService =  (AccountService) applicationContext.getBean("proxyAccountService");
        accountService.transfer("jack", "rose", 1000);
    }
  

• 测试结果：

image.png

一样报错，但是数据库没有实现错误转账，如图：

image.png

6.基于xml的aop事务配置

• 修改applicationContext.xml配置文件：

    <!--事务管理器的配置-->
     <bean id="txManager" class="org.springframework.jdbc.datasource.DataSourceTransactionManager">
       <property name="dataSource" ref="dataSource"/>
   </bean>
    <!-- 基于xml的aop事务配置 -->
    <tx:advice id="txAdvice" transaction-manager="txManager">
        <tx:attributes>
            <tx:method name="transfer" propagation="REQUIRED" isolation="DEFAULT"/>
        </tx:attributes>
    </tx:advice>
  
    <aop:config>
        <aop:advisor advice-ref="txAdvice" pointcut="execution(* com.cyy.service.impl.*.*(..))"/>
    </aop:config>
  

• 运行测试AppTest类的demo1()方法：

image.png

数据库：

image.png

7.基于注解的aop事务配置

• 在applicationContext.xml中将以上代理类的配置替换成

     <tx:annotation-driven transaction-manager="txManager"/>
  

• 在需要进行事务操作的类或者方法上进行加上注解 @Transactional，同时可以配置事务传播级别和事务隔离级别，例如：

  @Transactional(propagation = Propagation.REQUIRED,isolation = Isolation.DEFAULT)
  

简单解释一下，这里的传播级别设置的是REQUIRED,即支持当前事务，如果当前没有事务，就新建一个事务，一般默认采用此配置;隔离级别DEFAULT，使用数据库默认的事务隔离级别（MySQL 事务默认隔离级别是可重复读）。

• 再次查看测试结果：

  
  image.png

报错，数据库：

image.png