Spring IOC 源码学习声明式事务的入口点

一、Spring 声明式事务的入口点

对于XML入口点

XML配置定义

xml 复制代码

<?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:tx="http://www.springframework.org/schema/tx"
	   xsi:schemaLocation="
		http://www.springframework.org/schema/beans
		https://www.springframework.org/schema/beans/spring-beans.xsd
		http://www.springframework.org/schema/tx
		https://www.springframework.org/schema/tx/spring-tx.xsd
		http://www.springframework.org/schema/aop
		https://www.springframework.org/schema/aop/spring-aop.xsd">
	<tx:annotation-driven></tx:annotation-driven>

	<!-- dao bean-->
	<bean id="jdbcTemplate" class="org.springframework.jdbc.core.JdbcTemplate" >
		<property name="dataSource" ref = "dataSource"></property>
	</bean>

	<!-- service bean-->
	<bean id="bookService" class="org.yang.learn.spring.tx.BookService" >
		<property name="jdbcTemplate" ref="jdbcTemplate"></property>
	</bean>
	<!-- 数据源 bean-->
	<bean id="dataSource" class="com.alibaba.druid.pool.DruidDataSource" >
		<property name="driverClassName" value="com.mysql.cj.jdbc.Driver"></property>
		<property name="url"
				  value="jdbc:mysql://192.168.40.171:3306/workflow_test?serverTimezone=Asia/Shanghai&amp;characterEncoding=utf8&amp;useSSL=false"/>
		<property name="username" value="user_dev"></property>
		<property name="password" value="dev-sny.com"></property>
	</bean>
	<!-- 事务管理bean-->
	<bean id="transactionManager" class="org.springframework.jdbc.support.JdbcTransactionManager" >
		<constructor-arg ref="dataSource"></constructor-arg>
	</bean>
	<aop:config>
		<!--切点配置	-->
		<aop:pointcut id="serviceOperation"
					  expression="execution(* org.yang.learn.spring.tx.BookService.*(..))"/>
		<!-- 通知/增强 配置 (关键是这个通知指向 txAdvice '事务增强')-->
		<aop:advisor pointcut-ref="serviceOperation"  advice-ref="txAdvice"/>
	</aop:config>

	<tx:advice id="txAdvice" transaction-manager="transactionManager">
		<tx:attributes>
			<tx:method name="get*" read-only="true"/>
			<tx:method name="insertWithTransaction" propagation="REQUIRED" />
			<tx:method name="insertWithNoTransaction" propagation="NEVER" />
		</tx:attributes>
	</tx:advice>
</beans>

在XML中配置 tx:.. 启用tx标签, 在解析XML自定义标签时, 会拿到 TxNamespaceHandler 命名空间处理器, 其主要工作就是注册事务相关的标签的解析器

tx:advice 标签解析器：负责XML相关的标签解析 TxAdviceBeanDefinitionParser
tx:annotation-driven 标签解析器：负责注解相关的解析 AnnotationDrivenBeanDefinitionPar

org.springframework.transaction.config.TxNamespaceHandler

java 复制代码

public class TxNamespaceHandler extends NamespaceHandlerSupport {

	static final String TRANSACTION_MANAGER_ATTRIBUTE = "transaction-manager";

	static final String DEFAULT_TRANSACTION_MANAGER_BEAN_NAME = "transactionManager";


	static String getTransactionManagerName(Element element) {
		return (element.hasAttribute(TRANSACTION_MANAGER_ATTRIBUTE) ?
				element.getAttribute(TRANSACTION_MANAGER_ATTRIBUTE) : DEFAULT_TRANSACTION_MANAGER_BEAN_NAME);
	}


	@Override
	public void init() {
		//  <tx:advice> 标签解析器：负责解析XML <tx:advice> 事务标签配置 TxAdviceBeanDefinitionParser
		registerBeanDefinitionParser("advice", new TxAdviceBeanDefinitionParser());
		//  <tx:annotation-driven> 标签解析器：负责解析注解相关的事务配置 AnnotationDrivenBeanDefinitionParser
		registerBeanDefinitionParser("annotation-driven", new AnnotationDrivenBeanDefinitionParser());
		// JTA 规范的分布式事务管理器(管理跨多个资源的事务) TODO
		registerBeanDefinitionParser("jta-transaction-manager", new JtaTransactionManagerBeanDefinitionParser());
	}
}

启用事务注解支持

java 复制代码

class AnnotationDrivenBeanDefinitionParser implements BeanDefinitionParser {

	/**
	 * Parses the {@code <tx:annotation-driven/>} tag. Will
	 * {@link AopNamespaceUtils#registerAutoProxyCreatorIfNecessary register an AutoProxyCreator}
	 * with the container as necessary.
	 */
	@Override
	@Nullable
	public BeanDefinition parse(Element element, ParserContext parserContext) {
		registerTransactionalEventListenerFactory(parserContext);
		String mode = element.getAttribute("mode");
		if ("aspectj".equals(mode)) {
			// mode="aspectj"
			registerTransactionAspect(element, parserContext);
			if (ClassUtils.isPresent("jakarta.transaction.Transactional", getClass().getClassLoader())) {
				registerJtaTransactionAspect(element, parserContext);
			}
		}
		else {
			// 默认是  proxy 模式
			// mode="proxy"
			AopAutoProxyConfigurer.configureAutoProxyCreator(element, parserContext);
		}
		return null;
	}

注册三剑客

java 复制代码

/**
 * Inner class to just introduce an AOP framework dependency when actually in proxy mode.
 */
private static class AopAutoProxyConfigurer {

	public static void configureAutoProxyCreator(Element element, ParserContext parserContext) {
		AopNamespaceUtils.registerAutoProxyCreatorIfNecessary(parserContext, element);

		String txAdvisorBeanName = TransactionManagementConfigUtils.TRANSACTION_ADVISOR_BEAN_NAME;
		if (!parserContext.getRegistry().containsBeanDefinition(txAdvisorBeanName)) {
			Object eleSource = parserContext.extractSource(element);

			// Create the TransactionAttributeSource definition.
			RootBeanDefinition sourceDef = new RootBeanDefinition(
					"org.springframework.transaction.annotation.AnnotationTransactionAttributeSource");
			sourceDef.setSource(eleSource);
			sourceDef.setRole(BeanDefinition.ROLE_INFRASTRUCTURE);
			String sourceName = parserContext.getReaderContext().registerWithGeneratedName(sourceDef);

			// Create the TransactionInterceptor definition.
			RootBeanDefinition interceptorDef = new RootBeanDefinition(TransactionInterceptor.class);
			interceptorDef.setSource(eleSource);
			interceptorDef.setRole(BeanDefinition.ROLE_INFRASTRUCTURE);
			registerTransactionManager(element, interceptorDef);
			interceptorDef.getPropertyValues().add("transactionAttributeSource", new RuntimeBeanReference(sourceName));
			String interceptorName = parserContext.getReaderContext().registerWithGeneratedName(interceptorDef);

			/**
			 * 其中构建事务增强器(BeanFactoryTransactionAttributeSourceAdvisor)
			 * - **Pointcut（切点）**: 默认匹配所有标注 `@Transactional` 的类 / 方法（由 `TransactionAttributeSourcePointcut` 实现）
			 * - **Advice（通知）**: 即 `TransactionInterceptor`（事务拦截器）
			 * - **TransactionAttributeSource（注解解析器）**:即 `AnnotationTransactionAttributeSource`, 负责解析 `@Transactional` 注解的属性（传播行为、隔离级别等）。
			 */
			// Create the TransactionAttributeSourceAdvisor definition.
			RootBeanDefinition advisorDef = new RootBeanDefinition(BeanFactoryTransactionAttributeSourceAdvisor.class);
			advisorDef.setSource(eleSource);
			advisorDef.setRole(BeanDefinition.ROLE_INFRASTRUCTURE);
			advisorDef.getPropertyValues().add("transactionAttributeSource", new RuntimeBeanReference(sourceName));
			advisorDef.getPropertyValues().add("adviceBeanName", interceptorName);
			if (element.hasAttribute("order")) {
				advisorDef.getPropertyValues().add("order", element.getAttribute("order"));
			}
			parserContext.getRegistry().registerBeanDefinition(txAdvisorBeanName, advisorDef);

			CompositeComponentDefinition compositeDef = new CompositeComponentDefinition(element.getTagName(), eleSource);
			compositeDef.addNestedComponent(new BeanComponentDefinition(sourceDef, sourceName));
			compositeDef.addNestedComponent(new BeanComponentDefinition(interceptorDef, interceptorName));
			compositeDef.addNestedComponent(new BeanComponentDefinition(advisorDef, txAdvisorBeanName));
			parserContext.registerComponent(compositeDef);
		}
	}
}

事务注解支持的三剑客

AnnotationTransactionAttributeSource
↓（解析注解）
TransactionInterceptor
↓（执行事务逻辑）
BeanFactoryTransactionAttributeSourceAdvisor
↓（组装切点+通知）

总结一下XML入口, 就是无论 xml 支持还是注解支持都会构造 org.springframework.transaction.interceptor.TransactionInterceptor 这个核心 advice 事务拦截器

对于注解的入口

java 复制代码

@EnableTransactionManagement
public class TXMain {

	@Transactional
	public static void main(String[] args) throws Exception {
		System.out.println("==========================================================");
		//ApplicationContext context = new ClassPathXmlApplicationContext("application-tx.xml");
		AnnotationConfigApplicationContext context = new AnnotationConfigApplicationContext(TXMain.class);
		BookService bookService = context.getBean("bookService", BookService.class);
		Book book = new Book();
		book.setName("30秒精通javascript,一分钟精通java");
		book.setCode(""+System.currentTimeMillis());
//		bookService.insertWithTransaction(book );
		bookService.insertWithNoTransaction(book);
		System.out.println("bookService = "+bookService);
		System.out.println("bookService getList = "+bookService.getList());
		System.out.println("==========================================================");
	}
}

@EnableTransactionManagement 注解导入了 TransactionManagementConfigurationSelector 默认选中的是 ProxyTransactionManagementConfiguration

java 复制代码

public class TransactionManagementConfigurationSelector extends AdviceModeImportSelector<EnableTransactionManagement> {

	/**
	 * Returns {@link ProxyTransactionManagementConfiguration} or
	 * {@code AspectJ(Jta)TransactionManagementConfiguration} for {@code PROXY}
	 * and {@code ASPECTJ} values of {@link EnableTransactionManagement#mode()},
	 * respectively.
	 */
	@Override
	protected String[] selectImports(AdviceMode adviceMode) {
		return switch (adviceMode) {
		
			case PROXY -> new String[] {AutoProxyRegistrar.class.getName(),
					ProxyTransactionManagementConfiguration.class.getName()};
			case ASPECTJ -> new String[] {determineTransactionAspectClass()};
		};
	}

	private String determineTransactionAspectClass() {
		return (ClassUtils.isPresent("jakarta.transaction.Transactional", getClass().getClassLoader()) ?
				TransactionManagementConfigUtils.JTA_TRANSACTION_ASPECT_CONFIGURATION_CLASS_NAME :
				TransactionManagementConfigUtils.TRANSACTION_ASPECT_CONFIGURATION_CLASS_NAME);
	}

}

同样注解的三剑客

AnnotationTransactionAttributeSource
↓（解析注解）
TransactionInterceptor
↓（执行事务逻辑）
BeanFactoryTransactionAttributeSourceAdvisor
↓（组装切点+通知）

org.springframework.transaction.annotation.ProxyTransactionManagementConfiguration

java 复制代码

/*
 * Copyright 2002-2021 the original author or authors.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      https://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.springframework.transaction.annotation;

import org.springframework.beans.factory.config.BeanDefinition;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.context.annotation.ImportRuntimeHints;
import org.springframework.context.annotation.Role;
import org.springframework.transaction.config.TransactionManagementConfigUtils;
import org.springframework.transaction.interceptor.BeanFactoryTransactionAttributeSourceAdvisor;
import org.springframework.transaction.interceptor.TransactionAttributeSource;
import org.springframework.transaction.interceptor.TransactionInterceptor;

/**
 * {@code @Configuration} class that registers the Spring infrastructure beans
 * necessary to enable proxy-based annotation-driven transaction management.
 *
 * @author Chris Beams
 * @author Sebastien Deleuze
 * @since 3.1
 * @see EnableTransactionManagement
 * @see TransactionManagementConfigurationSelector
 */
@Configuration(proxyBeanMethods = false)
@Role(BeanDefinition.ROLE_INFRASTRUCTURE)
@ImportRuntimeHints(TransactionRuntimeHints.class)
public class ProxyTransactionManagementConfiguration extends AbstractTransactionManagementConfiguration {

	@Bean(name = TransactionManagementConfigUtils.TRANSACTION_ADVISOR_BEAN_NAME)
	@Role(BeanDefinition.ROLE_INFRASTRUCTURE)
	public BeanFactoryTransactionAttributeSourceAdvisor transactionAdvisor(
			TransactionAttributeSource transactionAttributeSource, TransactionInterceptor transactionInterceptor) {

		BeanFactoryTransactionAttributeSourceAdvisor advisor = new BeanFactoryTransactionAttributeSourceAdvisor();
		advisor.setTransactionAttributeSource(transactionAttributeSource);
		advisor.setAdvice(transactionInterceptor);
		if (this.enableTx != null) {
			advisor.setOrder(this.enableTx.<Integer>getNumber("order"));
		}
		return advisor;
	}

	@Bean
	@Role(BeanDefinition.ROLE_INFRASTRUCTURE)
	public TransactionAttributeSource transactionAttributeSource() {
		// Accept protected @Transactional methods on CGLIB proxies, as of 6.0.
		return new AnnotationTransactionAttributeSource(false);
	}

	@Bean
	@Role(BeanDefinition.ROLE_INFRASTRUCTURE)
	public TransactionInterceptor transactionInterceptor(TransactionAttributeSource transactionAttributeSource) {
		TransactionInterceptor interceptor = new TransactionInterceptor();
		interceptor.setTransactionAttributeSource(transactionAttributeSource);
		if (this.txManager != null) {
			interceptor.setTransactionManager(this.txManager);
		}
		return interceptor;
	}

}

Spring IOC 源码学习 声明式事务的入口点

一、Spring 声明式事务的入口点

对于XML入口点

启用事务注解支持

事务注解支持的三剑客

对于注解的入口

同样注解的三剑客

Spring IOC 源码学习声明式事务的入口点