CrudRepository中不见merge或update的踪影

看CrudRepository接口，进去一看，说好的crud，可是怎么不见merge或update呢？

再一看save注释：

 

/**
     * Saves a given entity. Use the returned instance for further operations as the save operation might have changed the
     * entity instance completely.
     *
     * @param entity
     * @return the saved entity
     */
    <S extends T> S save(S entity);

这。。。

点进去看一看有哪些实现。。。

只有SimpleJpaRepository中的实现：

 

/*
     * (non-Javadoc)
     * @see org.springframework.data.repository.CrudRepository#save(java.lang.Object)
     */
    @Transactional
    public <S extends T> S save(S entity) {

        if (entityInformation.isNew(entity)) {
            em.persist(entity);
            return entity;
        } else {
            return em.merge(entity);
        }
    }