java事务嵌套

Question

方法A:

classA

@Override
@Transactional(propagation = Propagation.REQUIRED)
public void testA(Student student) {
  ......
  try {
             classB.testB(student);
            } catch (CustomException e) {
                log.warn("失败，原因：" + e.getMessage());
                
            } catch (ParamException e) {
                log.warn("失败，原因：" + e.getMessage());
                
            } catch (Exception e) {
                log.error("失败，原因：" + e.getMessage(), e);
            }
}

classB

@Override
@Transactional(rollbackFor=Exception.class,propagation=Propagation.REQUIRES_NEW)

public void testB(Student student) {
   try{
   ......
   } catch (CustomException e) {
        throw e;
    } catch (ParamException e) {
        throw e;
    } catch (Exception e) {
        log.error("出错:" + e.getMessage(), e);
    }  

}
问题：
org.springframework.transaction.UnexpectedRollbackException: Transaction rolled back because it has been marked as rollback-only
该问题偶发，什么情况下会抛出此异常？求解

Answer 1

一般是事务嵌套的问题，就你现在的代码，一般不会出现这个问题的