["slug" being an entity attribute]
Spring Data offers an existsBy query method, which we can define in the PostRepository, as follows:
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@Repository
public interface PostRepository
extends JpaRepository<Post, Long> {
boolean existsBySlug(String slug);
}
[another] option to emulate existence is using a CASE WHEN EXISTS native SQL query:
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@Repository
public interface PostRepository
extends JpaRepository<Post, Long> {
@Query(value = """
SELECT
CASE WHEN EXISTS (
SELECT 1
FROM post
WHERE slug = :slug
)
THEN 'true'
ELSE 'false'
END
""",
nativeQuery = true
)
boolean existsBySlugWithCase(@Param("slug") String slug);
}
Statistical Theory and Method Abstracts (STMA) is now available as a component of Zentralblatt MATH, referred to as STMA-Z. Zentralblatt MATH is the one of the world’s most complete and longest running abstracting and reviewing services in pure and applied mathematics, containing more than 2 million entries drawn from more than 2,300 serials and journals, covering the period from 1868 to the present. STMA-Z contains all entries of ZMATH pertaining to statistics. Former entries of STMA are included to avoid duplication. Entries of Zentralblatt are classified since 1972 according to the Mathematics Subject Classification Scheme. STMA-Z will provide subscribers with specific access to statistical references and related fields.
Custom parsing / setting of handler arguments.
A custom HandlerMethodArgumentResolver might be written extending the RequestParamMethodArgumentResolver laveraging already existent parameter parsing functionlaity.
I had a similar problem and struggling, googling for 1 day. But it was a simple mistake that instead of:
{http://ws.somecompany.com/services}ValidateUser
It should be
{http://ws.somecompany.com/services/}ValidateUser