SpringTransaction事务实现流程源码解析

SET NAMES utf8mb4;
SET FOREIGN_KEY_CHECKS = 0;
-- ----------------------------
-- Table structure for user
-- ----------------------------
DROP TABLE IF EXISTS `user`;
CREATE TABLE `user`  (
  `id` bigint(20) NOT NULL AUTO_INCREMENT,
  `name` varchar(255) CHARACTER SET utf8mb4 COLLATE utf8mb4_general_ci NULL DEFAULT NULL,
  `age` int(11) NULL DEFAULT NULL,
  PRIMARY KEY (`id`) USING BTREE
) ENGINE = InnoDB AUTO_INCREMENT = 1 CHARACTER SET = utf8mb4 COLLATE = utf8mb4_general_ci ROW_FORMAT = Dynamic;
SET FOREIGN_KEY_CHECKS = 1;

    <dependencies>
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <version>5.1.46</version>
        </dependency>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-beans</artifactId>
            <version>5.3.18</version>
        </dependency>
        <!-- spring jdbc 依赖spring-tx -->
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-jdbc</artifactId>
            <version>5.3.18</version>
        </dependency>
        <dependency>
            <groupId>org.apache.commons</groupId>
            <artifactId>commons-dbcp2</artifactId>
            <version>2.7.0</version>
        </dependency>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-context</artifactId>
            <version>5.3.18</version>
        </dependency>
        <dependency>
            <groupId>junit</groupId>
            <artifactId>junit</artifactId>
            <version>4.13.2</version>
        </dependency>
    </dependencies>

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

    <tx:annotation-driven transaction-manager="transactionManager" proxy-target-class="true" mode="proxy"/>

    <tx:annotation-driven transaction-manager="transactionManager" proxy-target-class="true" mode="proxy"/>
    <bean id="transactionManager" class="org.springframework.jdbc.datasource.DataSourceTransactionManager">
        <property name="dataSource" ref="ds"/>
    </bean>

    <bean id="ds" class="org.apache.commons.dbcp2.BasicDataSource" destroy-method="close">
        <property name="driverClassName" value="com.mysql.jdbc.Driver"/>
        <property name="username" value="root"/>
        <property name="passWord" value="root"/>
        <property name="url" value="jdbc:mysql://localhost:3306/db0?useSSL=false"/>
        <property name="initialSize" value="5"/>
        <property name="maxIdle" value="2"/>
        <property name="maxTotal" value="100"/>
    </bean>

    <!-- 配置bean,指定数据源-->
    <bean id="userService" class="service.UserService">
        <property name="dataSource" ref="ds"/>
    </bean>

package service;
import org.springframework.jdbc.core.JdbcTemplate;
import org.springframework.transaction.annotation.Propagation;
import org.springframework.transaction.annotation.Transactional;
import javax.sql.DataSource;
@Transactional(propagation = Propagation.REQUIRED)
public class UserService {
    private JdbcTemplate jdbcTemplate;
    public void setDataSource(DataSource dataSource) {
        this.jdbcTemplate = new JdbcTemplate(dataSource);
    }
    public String getUserName(int id) {
        return jdbcTemplate.query("select * from db0.user where id= ?", rs -> rs.next() ? rs.getString(2) : "", new Object[]{id});
    }
    public void updateUser(int id, String name) {
        jdbcTemplate.update(" update  user set name =? where id= ?", new Object[]{name, id});
//        throw new RuntimeException("error!");
    }
}

import org.junit.Test;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;
import service.UserService;
public class UserServiceTests {
    @Test
    public void testTransaction() {
        ApplicationContext context = new ClassPathXmlApplicationContext("spring.xml");
        UserService userService = context.getBean("userService", UserService.class);
        String name = userService.getUserName(1);
        System.out.println("名字:"+name);
        userService.updateUser(1, "bing");
        String updateName = userService.getUserName(1);
        System.out.println("更新后的名字:" + updateName);
    }
}

package org.springframework.transaction.config;
import org.w3c.dom.Element;
import org.springframework.beans.factory.xml.NamespaceHandlerSupport;

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() {
		reGISterBeanDefinitionParser("advice", new TxAdviceBeanDefinitionParser());
		// 注册事务
		registerBeanDefinitionParser("annotation-driven", new AnnotationDrivenBeanDefinitionParser());
		registerBeanDefinitionParser("jta-transaction-manager", new JtaTransactionManagerBeanDefinitionParser());
	}
}

<tx:annotation-driven transaction-manager="transactionManager" mode="aspectj">

	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);
				// 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"));
				}
				// 事务通知器 transaction advisor, 基于AOP实现的advisor
				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);
			}
		}
	}

@FunctionalInterface
public interface MethodInterceptor extends Interceptor {
	
	Object invoke(MethodInvocation invocation) throws Throwable;
}

	@Override
	@Nullable
	public Object invoke(final MethodInvocation invocation) throws Throwable {
		// Work out the target class: may be {@code null}.
		// The TransactionAttributeSource should be passed the target class
		// as well as the method, which may be from an interface.
		Class<?> targetClass = (invocation.getThis() != null ? AopUtils.getTargetClass(invocation.getThis()) : null);
		// Adapt to TransactionAspectSupport's invokeWithinTransaction...
		return invokeWithinTransaction(invocation.getMethod(), targetClass, invocation::proceed);
	}

	if (txAttr == null || !(tm instanceof CallbackPreferringPlatformTransactionManager)) {
			// Standard transaction demarcation with getTransaction and commit/rollback calls.
			// 创建事务
			TransactionInfo txInfo = createTransactionIfNecessary(tm, txAttr, joinpointIdentification);
			Object retVal = null;
			try {
				// This is an around advice: Invoke the next interceptor in the chain.
				// This will normally result in a target object being invoked.
				retVal = invocation.proceedWithInvocation();
			} catch (Throwable ex) {
				// target invocation exception
				// 根据指定异常进行回滚。
				completeTransactionAfterThrowing(txInfo, ex);
				throw ex;
			} finally {
				cleanupTransactionInfo(txInfo);
			}
			// 提交事务
			commitTransactionAfterReturning(txInfo);
			return retVal;
		}

txInfo.getTransactionManager().rollback(txInfo.getTransactionStatus());