Spring Boot事务使用

Spring Boot实现事务特别特别简单，没有多余操作，一个注解@Transactional搞定

依赖的Jar包pom.xml

Spring Boot中实现事务没有额外的Jar包，还是基本的数据库访问包，比如Mybatis

<dependency>
    <groupId>org.mybatis.spring.boot</groupId>
    <artifactId>mybatis-spring-boot-starter</artifactId>
    <version>1.3.2</version>
</dependency>
<dependency>
    <groupId>mysql</groupId>
    <artifactId>mysql-connector-java</artifactId>
    <version>8.0.13</version>
</dependency>

注解事务@Transactional

@Service
public class PersonService {
    @Resource
    private PersonMapper personMapper;

    @Resource
    private CompanyMapper companyMapper;

    @Transactional(rollbackFor = {RuntimeException.class, Error.class})
    public void saveOne(Person person) {
        Company company = new Company();
        company.setName(person.getName());
        companyMapper.insertOne(company);
        personMapper.insertOne(person);
    }
}

ps：网络上还说要在@SpringBootApplication上添加注解@EnableTransactionManagement，已经不需要配置

默认回滚策略

默认遇到throw new RuntimeException("…");会回滚
需要捕获的throw new Exception("…");不会回滚

指定回滚策略

• 指定回滚

@Transactional(rollbackFor=Exception.class)
public void methodName() {
   // 不会回滚
   throw new Exception("...");
}

• 指定不回滚

@Transactional(noRollbackFor=Exception.class)
public ItemDaoImpl getItemDaoImpl() {
    // 会回滚
    throw new RuntimeException("注释");
}

注解属性

• @Transactional(rollbackFor = Exception.class)：触发回滚的异常，默认是RuntimeException和Error
• @Transactional(propagation = Propagation.REQUIRED)：如果有事务，那么加入事务，没有的话新建一个(不写的情况下)
• @Transactional(propagation = Propagation.NOT_SUPPORTED)：容器不为这个方法开启事务
• @Transactional(propagation = Propagation.REQUIRED, readOnly=true)：readOnly=true只读，不能更新，删除
• @Transactional(propagation = Propagation.REQUIRED, timeout=30)：设置超时时间
• @Transactional(propagation = Propagation.REQUIRED, isolation=Isolation.DEFAULT): 事务的隔离级别，即数据库隔离级别，默认是Isolation.DEFAULT也就是数据库自身的默认隔离级别，比如MySQL是ISOLATION_REPEATABLE_READ可重复读