解决Could not commit JPA transaction RollbackException: Transaction marked as rollbackOnly

项目测试发生问题，方法正常结束，但是报了

Could not commit JPA transaction; nested exception is javax.persistence.RollbackException: Transaction marked as rollbackOnly org.springframework.transaction.TransactionSystemException: Could not commit JPA transaction; nested exception is javax.persistence.RollbackException: Transaction marked as rollbackOnly
    at org.springframework.orm.jpa.JpaTransactionManager.doCommit(JpaTransactionManager.java:521)
    at org.springframework.transaction.support.AbstractPlatformTransactionManager.processCommit(AbstractPlatformTransactionManager.java:754)
    at org.springframework.transaction.support.AbstractPlatformTransactionManager.commit(AbstractPlatformTransactionManager.java:723)
    at org.springframework.transaction.interceptor.TransactionAspectSupport.commitTransactionAfterReturning(TransactionAspectSupport.java:393)
    at org.springframework.transaction.interceptor.TransactionInterceptor.invoke(TransactionInterceptor.java:120)
    at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:172)
    at org.springframework.aop.framework.Cglib2AopProxy$DynamicAdvisedInterceptor.intercept(Cglib2AopProxy.java:622)

错误，问什么不能提交呢?

经过查找发现了这么一段话

I finally understood the problem:
 
methodA() {
    methodB()
}
 
@Transactional(noRollbackFor = Exception.class)
methodB() {
    ...
    try {
        methodC()
    } catch (...) {...}
    log("OK");
}
 
@Transactional
methodC() {
    throw new ...();
}
What happens is that even though the methodB has the right annotation, the methodC does not. When the exception is thrown, the second @Transactional marks the first transaction as Rollback only anyway.

原来，在一个transactional中如果有另一transaction发生了异常，即使你捕捉了这个异常，那么Transaction也会被定义成RollbackOnly，这也正是事务管理的原则，可是我的系统哪里出异常了呢？

原来，spring jpa JpaRepository的实现方法中用ID删除的源码是这样的

@Transactional
    public void delete(ID id) {
 
        Assert.notNull(id, ID_MUST_NOT_BE_NULL);
 
        T entity = findOne(id);
 
        if (entity == null) {
            throw new EmptyResultDataAccessException(String.format("No %s entity with id %s exists!",
                    entityInformation.getJavaType(), id), 1);
        }
 
        delete(entity);
    }

他是这样实现的，先查找这个ID的对象看是否存在如果不存在则直接抛出一个非检查型异常，就不再执行delete操作。这和我平常习惯认为的不太一样，一般我习惯删除没有的记录不会报错，执行sql也是这样的。而我只是在外面捕捉了这个异常，所以发生的这样的问题。