Spring如何在一个事务中开启另一个事务

@Transactional(propagation =Propagation.REQUIRES_NEW) // 开启一个新事务

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;
import org.springframework.transaction.annotation.Propagation;
import org.springframework.transaction.annotation.Transactional;
import qinfeng.zheng.learnpagequery.domain.UserDO;
import qinfeng.zheng.learnpagequery.mapper.UserMapper;

@Service
public class UserService {
  @Autowired
  private UserMapper userMapper;


  @Transactional(rollbackFor = Exception.class)
  public void doSomething(UserDO userDo) {
    insert(userDo);
    doOther();
  }

  @Transactional(propagation =Propagation.REQUIRES_NEW) // 开启一个新事务
  public void insert(UserDO userDo) {
    userMapper.insert(userDo);
  }

  public void doOther() {
    System.out.println("做一些其它的事,比如调用其它的系统");
  }
}

@EnableAspectJAutoProxy(proxyTargetClass = true, exposeProxy = true)

@Transactional(rollbackFor = Exception.class)
public void doSomething(UserDO userDo) {
  UserService userService = (UserService) AopContext.currentProxy();
  userService.insert(userDo); // 这样insert方法事务生效
  doOther();
}