SpringBoot中异步执行事务REQUIRED和REQUIRED

SpringBoot中异步执行事务REQUIRED和REQUIRED_NEW的区别

springboot中事务的使用方式

在spring的bean中，要开启数据库事务只需要在方法中标注注解

@Transactional

注解常用的参数有

Class[] rollbackFor() default {} 指定回滚异常
Propagation propagation() default Propagation.REQUIRED 事务的传播机制
Isolation isolation() default Isolation.DEFAULT 事务的隔离级别

事务传播机制REQUIRED和REQUIRED_NEW

REQUIRED是默认的级别，如果当前没有事务，创建新事务；如果有事务，加入当前事务

REQUIRED_NEW 如果无论当前有没有事务，开启一个新的事务

Spring异步注解@Async

启动类中加入注解@EnableAsync

@Async注解标注在方法中，使方法异步执行

测试

通过调用接口新增数据

test1方法中保存了code为-1的一条数据

test2方法中保存了code为0~9的十条数据，插入第四条数据会抛出异常报错

    @Resourceprivate TestBaseService testBaseService;@Resourceprivate ApplicationContext applicationContext;@GetMapping("/add")@Transactional(rollbackFor = Exception.class, propagation = Propagation.REQUIRED)public void test1() {TestBaseEntity preEntity = new TestBaseEntity();preEntity.setCode("-1");testBaseService.save(preEntity);TestBaseController bean = applicationContext.getBean(TestBaseController.class);for (int i = 0; i < 10; i++) {TestBaseEntity entity = new TestBaseEntity();entity.setCode(String.valueOf(i));bean.test2(entity, i);}}//@Async//@Transactional(rollbackFor = Exception.class, propagation = Propagation.REQUIRES_NEW)public void test2(TestBaseEntity entity, int i) {testBaseService.save(entity);if (i == 4) {throw new RuntimeException("异常");}}

调用接口，发现没有数据新增

因为只设置了一个事务，有异常会导致事务回滚;有一条失败全部失败

test1设置事务提交后，再执行test2

@GetMapping("/add")
@Transactional(rollbackFor = Exception.class, propagation = Propagation.REQUIRED)
public void testTransactional() {TestBaseEntity preEntity = new TestBaseEntity();preEntity.setCode("-1");testBaseService.save(preEntity);TestBaseController bean = applicationContext.getBean(TestBaseController.class);for (int i = 0; i < 10; i++) {TestBaseEntity entity = new TestBaseEntity();entity.setCode(String.valueOf(i));int finalI = i;TransactionSynchronizationManager.registerSynchronization(new TransactionSynchronization() {@Overridepublic void afterCommit() {bean.saveTest(entity, finalI);TransactionSynchronization.super.afterCommit();}});}
}

结果图

可以看到 -1 ~ 4都新增成功了

因为手动将test1的事务提交了，而test2没有事务，所有即便报错也没有回滚，code=4正常插入

test2传播机制设置为REQUIRED_NEW

@Transactional(rollbackFor = Exception.class, propagation = Propagation.REQUIRES_NEW)public void test2(TestBaseEntity entity, int i) {testBaseService.save(entity);if (i == 4) {throw new RuntimeException("异常");}}

调用接口，结果如下

test1的事务不会因为test2的报错而受到影响，执行的10次test2每次都是一个新的事务

当code=4时，发生异常，当前事务回滚，程序返回，所以code=4的数据回滚了，后面的5-9根本没有执行新增插入

test2传播机制设置为REQUIRED_NEW，开启@Async注解

@Async
@Transactional(rollbackFor = Exception.class, propagation = Propagation.REQUIRES_NEW)public void test2(TestBaseEntity entity, int i) {testBaseService.save(entity);if (i == 4) {throw new RuntimeException("异常");}}