Infobip Spring Data JPA Querydsl provides new functionality that enables the user to leverage the full power of Querydsl API on top of Spring Data repository infrastructure.
- News
- Features and examples
- Setup
- Domain Driven Design concerns
- Requirements
- Further reading
- Running tests
- Contributing
- License
Changed scope of SimpleExtendedQueryDslJpaRepository to public.
Upgrade to Spring Data 2 (Spring Boot 2).
Breaking change: new repository methods introduced in Spring Data 2 CrudRepository#findById(Object)
and
QuerydslPredicateExecutor#findOne(Predicate)
replace old ExtendedQueryDslJpaRepository.findOneById(Object)
and ExtendedQueryDslJpaRepository.findOneByPredicate(Predicate)
(they were removed).
All examples have corresponding tests in the project and can be found here.
Example which uses union clause (unions aren't available in JPA):
List<Person> actual = repository.jpaSqlQuery(query -> query
.union(
repository.jpaSqlSubQuery(subQuery ->
subQuery.select(person)
.from(person)
.where(person.firstName.like("John"))),
repository.jpaSqlSubQuery(subQuery ->
subQuery.select(person)
.from(person)
.where(person.firstName.like("Jan%")))
)
.orderBy(person.firstName.asc(), person.lastName.asc())
.fetch()
);
For examples how to construct projections refer to the official documentation - section result handling.
Here is an example that uses constructor:
@Value
public class PersonProjection {
private final String firstName;
private final String lastName;
}
...
List<PersonProjection> actual = repository.query(query -> query
.select(Projections.constructor(PersonProjection.class, person.firstName, person.lastName))
.from(person)
.fetch());
Query exposes full API of JPAQuery (QueryDslPredicateExecutor only exposes where clause (Predicate) and order clause (OrderSpecifier)).
This along with Querydsl 4 API improvement can lead to code that looks more like regular SQL:
List<Person> actual = repository.query(query -> query
.select(person)
.from(person)
.where(person.firstName.in("John", "Jane"))
.orderBy(person.firstName.asc(), person.lastName.asc())
.limit(1)
.offset(1)
.fetch());
repository.update(query -> query
.set(person.firstName, "John")
.where(person.firstName.eq("Johny"))
.execute());
long numberOfAffectedRows = repository.deleteWhere(person.firstName.like("John%"));
QueryDslPredicateExecutor#findAll methods return Iterable which can be cumbersome to use. Those methods were overridden and now return a List which is easier to use and is easier to convert to Stream.
Query execution is always done inside the repository implementation (loan pattern) in a transaction so transactions don't have to be handled manually (like they do if you are manually managing JPAQuery and other Querydsl constructs).
JPA support for stored procedures is quite cumbersome and it also requires a reference to EntityManager which leads to code like this:
@PersistenceContext
private EntityManager entityManager
...
@SuppressWarnings("unchecked")
public List<Person> delete(Person personToDelete) {
return (List<Person>) entityManager
.createStoredProcedureQuery("Person_Delete")
.registerStoredProcedureParameter("FirstName", String.class, ParameterMode.IN)
.registerStoredProcedureParameter("LastName", String.class, ParameterMode.IN)
.setParameter("FirstName", personToDelete.getFirstName())
.setParameter("LastName", personToDelete.getLastName())
.getResultList(); // returns untyped List => unchecked
}
For this case, executeStoredProcedure method was added which supports Q class attributes:
public List<Person> delete(Person personToDelete) {
return repository.executeStoredProcedure(
"Person_Delete",
builder -> builder.addInParameter(person.firstName, personToDelete.getFirstName())
.addInParameter(person.lastName, personToDelete.getLastName())
.getResultList());
}
- Dependency:
<dependency>
<groupId>com.infobip</groupId>
<artifactId>infobip-spring-data-jpa-querydsl</artifactId>
<version>${infobip-spring-data-jpa-querydsl.version}</version>
</dependency>
As this project depends on querydsl-apt with jpa classifier you don't need to set up explicit Maven build phase for Q classes generation. For building Q classes without Maven, make sure your IDE has Annotation processing enabled.
- Add @EnableExtendedRepositories to your Main class:
@EnableExtendedRepositories // replaces @EnableJpaRepositories
@SpringBootApplication
public class Main {
public static void main(String[] args) {
new SpringApplicationBuilder(Main.class).run(args);
}
}
- Refactor repository interfaces to use
ExtendedQueryDslJpaRepository
instead ofJpaRepository
andQueryDslPredicateExecutor
(note that ExtendedQueryDslJpaRepository extends and provides the API of both):
// ExtendedQueryDslJpaRepository replaces both JpaRepository and QueryDslPredicateExecutor
interface FooRepository extends ExtendedQueryDslJpaRepository<Foo, ID> {
}
- Done
If you need other features from @EnableJpaRepositories
you can use:
@EnableJpaRepositories(repositoryBaseClass = SimpleExtendedQueryDslJpaRepository.class)
In following example one could argue that database related logic has leaked from repository to service layer:
class FooService {
private final FooRepository repository;
...
List<Foo> findAll(String barName, Long limit, Long offset) {
...
return repository.query(query -> query.select(foo)
.from(foo)
.where(foo.bar.name.eq(barName))
.limit(limit)
.offset(offset)
.fetch());
}
}
In order to prevent this, you can customize the repository.
First, create a custom repository:
interface FooCustomRepository {
List<Foo> findAll(String barName, Long limit, Long offset);
}
Make FooRepository
extend FooCustomRepository
:
interface FooRepository extends ExtendedQueryDslJpaRepository<Foo, ID>, FooCustomRepository {
}
Provide an implementation for FooCustomRepository
:
class FooCustomRepositoryImpl implements FooCustomRepository {
private final ExtendedQueryDslJpaRepository<Foo, ID> repository;
FooCustomRepositoryImpl(@Lazy ExtendedQueryDslJpaRepository<Foo, ID> repository) {
this.repository = repository;
}
@Override
public List<Foo> findAll(String barName, Long limit, Long offset) {
return repository.query(query -> query.select(foo)
.from(foo)
.where(foo.bar.name.eq(barName))
.limit(limit)
.offset(offset)
.fetch());
}
}
Refactor service layer to use the new method:
class FooService {
private final FooRepository repository;
...
List<Foo> findAll(String barName, Long limit, Long offset) {
...
return repository.findAll(barName, limit, offset);
}
}
- Java 8
- Hibernate (if you need support for other JPA implementors please open an issue)
- Spring Data
- Querydsl
- Querydsl documentation
- Atlassian Querydsl examples
- Querydsl google group
- Spring Data JPA documentation
Tests require SQL Server DB.
Easies way to set it up on your machine is to use docker:
docker run -e 'ACCEPT_EULA=Y' -e 'SA_PASSWORD=<YourStrong!Passw0rd>' -p 1433:1433 -d microsoft/mssql-server-linux:2017-latest
If you have an idea for a new feature or want to report a bug please use the issue tracker.
Pull requests are welcome!
This library is licensed under the Apache License, Version 2.0.