如何在 JPA 中使用规范

Question

I am implementing search functionality in my application. I am using Specification in findAll() and it is working perfectly. But when ever i am trying to achive in other methods like findByFirstName() it is not working

I am including what i did so far.

AircraftSpecification.java

public class AircraftSpecification {

    private AircraftSpecification() {}

    public static Specification<Aircraft> textInAllColumns(String text) {

        if (!text.contains("%")) {
            text = "%"+text+"%";
        }
        final String finalText = text;

        return new Specification<Aircraft>() {
            private static final long serialVersionUID = 1L;

            @Override
            public Predicate toPredicate(Root<Aircraft> root, CriteriaQuery<?> cq, CriteriaBuilder builder) {
                  List<SingularAttribute<Aircraft, ?>> tempAttributes = new ArrayList<>();
                  for (SingularAttribute<Aircraft, ?> attribute : root.getModel().getDeclaredSingularAttributes()) {
                      if (attribute.getJavaType().getSimpleName().equalsIgnoreCase("string")) {
                          tempAttributes.add(attribute);
                      }
                  }

                  final Predicate[] predicates = new Predicate[tempAttributes.size()];

                  for (int i = 0; i < tempAttributes.size(); i++) {
                      predicates[i] = builder.like(builder.lower(root.get(tempAttributes.get(i).getName())), finalText.toLowerCase());
                  }
                  return builder.or(predicates);
              }
        };
    }
}

When i am calling

aircraftRepository.findAll(Specification.where(AircraftSpecification.textInAllColumns(searchText)));

it giving me proper data.

But when i am calling

aircraftRepository.findAllByName(name, Specification.where(AircraftSpecification.textInAllColumns(searchText)));

It throwing Exception.

Exception Is:

org.springframework.dao.InvalidDataAccessApiUsageException: At least 2 parameter(s) provided but only 1 parameter(s) present in query.; nested exception is java.lang.IllegalArgumentException: At least 2 parameter(s) provided but only 1 parameter(s) present in query.

Can any one help me how to use Specification other than findAll method.

Answer 1

You can't combine derived queries where Spring Data derives the query to execute from the method name with Specification . Just make the name part of a query a Specification as well and combine the two with and.

The resulting call could look like this or similar:

aircraftRepository.findAll(
        byName("Alfred")
       .and(textInAllColumns(searchText))
);