一 事务信息配置

• 配置事务管理器及数据库连接池

<bean id="transactionManager" class="org.springframework.jdbc.datasource.DataSourceTransactionManager">
    <property name="dataSource" ref="dataSource"/>
</bean>

• 配置事务注解@Transactional处理，注入事务管理器
  <tx:annotation-driven transaction-manager="transactionManager" proxy-target-class="true"/>
• 注入事务管理器transactionManager到事务调用代理函数TransactionInterceptor中，代理类调用时用于创建并管理事务。

RootBeanDefinition interceptorDef = new RootBeanDefinition(TransactionInterceptor.class);
interceptorDef.setSource(eleSource);
interceptorDef.setRole(2);
AnnotationDrivenBeanDefinitionParser.registerTransactionManager(element, interceptorDef);
interceptorDef.getPropertyValues().add("transactionAttributeSource", new RuntimeBeanReference(sourceName));
String interceptorName = parserContext.getReaderContext().registerWithGeneratedName(interceptorDef);

• TransactionInterceptor实现接口MethodInterceptor用于aop代理调用

public interface MethodInterceptor extends Interceptor {
    
    /**
     * Implement this method to perform extra treatments before and
     * after the invocation. Polite implementations would certainly
     * like to invoke {@link Joinpoint#proceed()}.
     *
     * @param invocation the method invocation joinpoint
     * @return the result of the call to {@link
     * Joinpoint#proceed()}, might be intercepted by the
     * interceptor.
     *
     * @throws Throwable if the interceptors or the
     * target-object throws an exception.  */
    Object invoke(MethodInvocation invocation) throws Throwable;
}

• 封装Advisor类，aop创建代理类时会获取advisor接口实现类，匹配待创建的bean，匹配成功则创建aop代理。

RootBeanDefinition advisorDef = new RootBeanDefinition(BeanFactoryTransactionAttributeSourceAdvisor.class);
advisorDef.setSource(eleSource);
advisorDef.setRole(2);
//pointcut 切入点，通过注解参数初始化
advisorDef.getPropertyValues().add("transactionAttributeSource", new RuntimeBeanReference(sourceName));
//advise 通知，代理调用
advisorDef.getPropertyValues().add("adviceBeanName", interceptorName);
if(element.hasAttribute("order")) {
    advisorDef.getPropertyValues().add("order", element.getAttribute("order"));
}
parserContext.getRegistry().registerBeanDefinition(txAdvisorBeanName, advisorDef);

• aop调用TransactionAttributeSourcePointcut类方法match匹配目标类方法是否需要创建事务代理

@Override
public boolean matches(Method method, Class<?> targetClass) {
    if (TransactionalProxy.class.isAssignableFrom(targetClass)) {
        return false;
    }
    TransactionAttributeSource tas = getTransactionAttributeSource();
    return (tas == null || tas.getTransactionAttribute(method, targetClass) != null);
}

二 事务创建流程

spring事务.png