Spring@querydslpredicate问题

Question

Spring Boot1.3.2.释放

QueryDSL 3.7.2

因此，我的实体是这样设置的：

person.java

@Data
@Entity
@Audited
public class Person {

    @Id
    private long id;

    private String name;

    private List<Pet> pets = new ArrayList<>();

}

Pet.java

@Data
@Entity
@Audited
public class Pet {

    @Id
    private long id;

    private int age;

}

public final ListPath<com.test.Pet, com.test.QPet> pets = this.<com.test.Pet, com.test.QPet>createList("pets", com.test.Pet.class, com.test.QPet.class, PathInits.DIRECT2);

10:21:37,523 ERROR [org.springframework.boot.context.web.ErrorPageFilter] (http-/127.0.0.1:8080-1) Forwarding to error page from request [/list] due to exception [null]: java.lang.NullPointerException
    at org.springframework.util.ReflectionUtils.getField(ReflectionUtils.java:143) [spring-core-4.2.4.RELEASE.jar:4.2.4.RELEASE]
    at org.springframework.data.querydsl.binding.QuerydslPredicateBuilder.reifyPath(QuerydslPredicateBuilder.java:185) [spring-data-commons-1.11.2.RELEASE.jar:]
    at org.springframework.data.querydsl.binding.QuerydslPredicateBuilder.reifyPath(QuerydslPredicateBuilder.java:188) [spring-data-commons-1.11.2.RELEASE.jar:]
    at org.springframework.data.querydsl.binding.QuerydslPredicateBuilder.getPath(QuerydslPredicateBuilder.java:167) [spring-data-commons-1.11.2.RELEASE.jar:]
    at org.springframework.data.querydsl.binding.QuerydslPredicateBuilder.invokeBinding(QuerydslPredicateBuilder.java:136) [spring-data-commons-1.11.2.RELEASE.jar:]
    at org.springframework.data.querydsl.binding.QuerydslPredicateBuilder.getPredicate(QuerydslPredicateBuilder.java:111) [spring-data-commons-1.11.2.RELEASE.jar:]
    at org.springframework.data.web.querydsl.QuerydslPredicateArgumentResolver.resolveArgument(QuerydslPredicateArgumentResolver.java:106) [spring-data-commons-1.11.2.RELEASE.jar:]
    at org.springframework.data.web.querydsl.QuerydslPredicateArgumentResolver.resolveArgument(QuerydslPredicateArgumentResolver.java:48) [spring-data-commons-1.11.2.RELEASE.jar:]
    at org.springframework.web.method.support.HandlerMethodArgumentResolverComposite.resolveArgument(HandlerMethodArgumentResolverComposite.java:78) [spring-web-4.2.4.RELEASE.jar:4.2.4.RELEASE]

Field field = ReflectionUtils.findField(entityPath.getClass(), path.getSegment());
Object value = ReflectionUtils.getField(field, entityPath);

http://localhost:8080/test-app/list？name=bob

我的预期是，通过使用？pets.age=5，将构建以下谓词：

QPerson.person.pets.any().age.eq(5)

在Spring的QuerydslPredicate支持下，这是可能的吗？还是应该从查询参数手动构建谓词？

final BooleanBuilder petBuilder = new BooleanBuilder();
petBuilder.and(QPet.firstName.equals("Bob").or(QPet.lastName.equals("Bob")));

如果这些都不可能，那么我将继续手动创建谓词，并将其传递到存储库。

Answer 1

您可以使用QueryDSLBinderCustomizer来实现您的目的。以下是一些可以帮助您解决问题的示例代码：

public interface PersonRepository extends JpaRepository<Job, Integer>,
        QueryDslPredicateExecutor<Person>, QuerydslBinderCustomizer<QJob> {

    @Override
    public default void customize(final QuerydslBindings bindings, final QPerson person)     {
        bindings.bind(person.pets.any().name).first((path, value) -> {
            return path.eq(value);
        });
    }
}