1.Spring框架配置事务

1.1基于schema的自动代理

<beans xmlns="http://www.springframework.org/schema/beans"
       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
       xmlns:p="http://www.springframework.org/schema/p"
       xmlns:tx="http://www.springframework.org/schema/tx"
       xmlns:aop="http://www.springframework.org/schema/aop"
       xsi:schemaLocation="http://www.springframework.org/schema/beans
        http://www.springframework.org/schema/beans/spring-beans-4.0.xsd
        http://www.springframework.org/schema/aop
        http://www.springframework.org/schema/aop/spring-aop-4.0.xsd
        http://www.springframework.org/schema/tx
        http://www.springframework.org/schema/tx/spring-tx-4.0.xsd">

    <!--对数据源进行代理，使数据源具有感知事务上下文的能力，当某些场景下显示获取数据库连接时，保证获取到的连接是绑定了当前事务的连接（和通过DataSourceUtils.getConnection()获取连接的效果一致）-->
    <bean id="dataSourceProxy" class="org.springframework.jdbc.datasource.TransactionAwareDataSourceProxy"
        p:targetDataSource-ref="dataSource"/>

    <!--声明式事务管理器-->
    <bean id="txManager"
          class="org.springframework.jdbc.datasource.DataSourceTransactionManager"
        p:dataSource-ref="dataSourceProxy"/>

    <!--基于schema的自动代理-->
    <aop:config>
        <!--切点 匹配com.fxy子包下的所有方法-->
        <aop:pointcut id="serviceMethod"
                      expression="execution(* com.fxy..*.*.service..*.*(..))"/>
        <!--切面-->
        <aop:advisor pointcut-ref="serviceMethod" advice-ref="txAdvice"/>
    </aop:config>
    <!--增强 新增变更删除方法 遇到检查型异常和非检查型异常均回滚-->
    <tx:advice id="txAdvice" transaction-manager="txManager">
        <tx:attributes>
            <tx:method name="get*" read-only="true"/>
            <tx:method name="list*" read-only="true"/>
            <tx:method name="save*" rollback-for="Exception"/>
            <tx:method name="update*" rollback-for="Exception"/>
            <tx:method name="delete*" rollback-for="Exception"/>
            <tx:method name="*" rollback-for="Exception"/>
        </tx:attributes>
    </tx:advice>
</beans>

查看tx:advice标签，可以追踪到TransactionInterceptor类，其实现了MethodInterceptor接口，会在目标方法前后实施增强（即使用txManager，在方法执行前关闭Connection对象自动提交，方法执行完成后执行Connection对象提交方法，异常时执行Connection对象回滚方法）。

1.2使用@transactional注解

<beans xmlns="http://www.springframework.org/schema/beans"
       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
       xmlns:p="http://www.springframework.org/schema/p"
       xmlns:tx="http://www.springframework.org/schema/tx"
       xmlns:aop="http://www.springframework.org/schema/aop"
       xsi:schemaLocation="http://www.springframework.org/schema/beans
        http://www.springframework.org/schema/beans/spring-beans-4.0.xsd
        http://www.springframework.org/schema/aop
        http://www.springframework.org/schema/aop/spring-aop-4.0.xsd
        http://www.springframework.org/schema/tx
        http://www.springframework.org/schema/tx/spring-tx-4.0.xsd">

    <!--对数据源进行代理，使数据源具有感知事务上下文的能力，当某些场景下显示获取数据库连接时，保证获取到的连接是绑定了当前事务的连接（和通过DataSourceUtils.getConnection()获取连接的效果一致）-->
    <bean id="dataSourceProxy" class="org.springframework.jdbc.datasource.TransactionAwareDataSourceProxy"
        p:targetDataSource-ref="dataSource"/>

    <!--声明式事务管理器-->
    <bean id="txManager"
          class="org.springframework.jdbc.datasource.DataSourceTransactionManager"
        p:dataSource-ref="dataSourceProxy"/>

    <!--对使用transactional注解的bean进行加工，织入事务管理切面 -->
    <tx:annotation-driven transaction-manager="txManager"/>
</beans>

2.SpringBoot框架配置事务

2.1@Transactional注解

2.1.1SpringBoot自动装配事务管理器

package org.springframework.boot.autoconfigure.jdbc;

import javax.sql.DataSource;
import org.springframework.beans.factory.ObjectProvider;
import org.springframework.boot.autoconfigure.AutoConfigureOrder;
import org.springframework.boot.autoconfigure.condition.ConditionalOnClass;
import org.springframework.boot.autoconfigure.condition.ConditionalOnMissingBean;
import org.springframework.boot.autoconfigure.condition.ConditionalOnSingleCandidate;
import org.springframework.boot.autoconfigure.transaction.TransactionManagerCustomizers;
import org.springframework.boot.context.properties.EnableConfigurationProperties;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.core.env.Environment;
import org.springframework.jdbc.core.JdbcTemplate;
import org.springframework.jdbc.datasource.DataSourceTransactionManager;
import org.springframework.jdbc.support.JdbcTransactionManager;
import org.springframework.transaction.TransactionManager;

@Configuration(
    proxyBeanMethods = false
)
@ConditionalOnClass({JdbcTemplate.class, TransactionManager.class})
@AutoConfigureOrder(2147483647)
@EnableConfigurationProperties({DataSourceProperties.class})
public class DataSourceTransactionManagerAutoConfiguration {
	public DataSourceTransactionManagerAutoConfiguration() {
    }

    @Configuration(
        proxyBeanMethods = false
    )
    @ConditionalOnSingleCandidate(DataSource.class)
    static class JdbcTransactionManagerConfiguration {
        JdbcTransactionManagerConfiguration() {
        }

        @Bean
        @ConditionalOnMissingBean({TransactionManager.class})
        DataSourceTransactionManager transactionManager(Environment environment, DataSource dataSource, ObjectProvider<TransactionManagerCustomizers> transactionManagerCustomizers) {
            DataSourceTransactionManager transactionManager = this.createTransactionManager(environment, dataSource);
            transactionManagerCustomizers.ifAvailable((customizers) -> {
                customizers.customize(transactionManager);
            });
            return transactionManager;
        }

        private DataSourceTransactionManager createTransactionManager(Environment environment, DataSource dataSource) {
            return (DataSourceTransactionManager)((Boolean)environment.getProperty("spring.dao.exceptiontranslation.enabled", Boolean.class, Boolean.TRUE) ? new JdbcTransactionManager(dataSource) : new DataSourceTransactionManager(dataSource));
        }
    }
}

2.2SpringBoot多数据源配置

2.2.1给数据源指定事务管理器

   @Bean("db1TxManager")
   public DataSourceTransactionManager db1TxManager(@Qualifier("db1DataSource") DataSource dataSource ){
       DataSourceTransactionManager txManager = new DataSourceTransactionManager();
       txManager.setDataSource(dataSource);
       return txManager;
   }
   @Bean("db2TxManager")
   public DataSourceTransactionManager db2TxManager(@Qualifier("db2DataSource") DataSource dataSource ){
       DataSourceTransactionManager txManager = new DataSourceTransactionManager();
       txManager.setDataSource(dataSource);
       return txManager;
   }

2.2.2注解上指定事务管理器

@Service("baseService1")
@Transactional("db1TxManager")
public class BaseService1 {
...
}