Hibernate 带有枚举字段的搜索/Lucene 范围查询不返回任何结果

Question

When using Hibernate Search with the following enum field:

public class UserSkill {
    @Enumerated
    @Field
    private UserSkillLevel level; // <- this is the field we're using on the ranged query
}

public class User { // <- this is the root class
    @IndexedEmbedded
    private Set<UserSkill> skills = new HashSet<>();
}

This is the enum:

public enum UserSkillLevel {
    JUNIOR,
    CONFIRMED,
    ADVANCED,
    EXPERT
}

When attempting to do a ranged query:

var fullTextEntityManager = Search.getFullTextEntityManager(entityManager);

var queryBuilder = fullTextEntityManager.getSearchFactory().buildQueryBuilder().forEntity(User.class).get();

var bq = new BooleanQuery.Builder();

var q = queryBuilder.range().onField("skills.level").above(UserSkillLevel.ADVANCED).createQuery();
bq.add(q, BooleanClause.Occur.MUST);

return fullTextEntityManager.createFullTextQuery(bq.build(), User.class).getResultList();

The problem is that no results are being returned, even if a user has a advanced or expert skill.

Answer 1

Enums are indexes as strings by default, so the range you asked for is actually "every skill level whose name is alphabetically after the word 'ADVANCED'" .

Thus I'd expect this to match everything instead; maybe you forgot to reindex your data after you changed your mapping?

Regardless... If you want to index your enums as their ordinal, implement a custom bridge:

public class EnumAsIntegerBridge implements MetadataProvidingFieldBridge {
    @Override
    public void configureFieldMetadata(String name, FieldMetadataBuilder builder) {
        builder.field( name, FieldType.INTEGER );
    }

    @Override
    public void set(String name, Object value, Document document, LuceneOptions luceneOptions) {
        Enum<?> enum = (Enum<?>) value;

        if ( enum != null ) {
            luceneOptions.addNumericFieldToDocument( name, enum.ordinal(), document );
        }
    }
}

Then use it in your mapping:

public class UserSkill {
    @Enumerated
    @Field(bridge = @FieldBridge(impl = EnumAsIntegerBridge.class))
    private UserSkillLevel level;
}

public class User {
    @IndexedEmbedded
    private Set<UserSkill> skills = new HashSet<>();
}

And pass the ordinal instead of the enum to the query:

var q = queryBuilder.range().onField("skills.level").above(UserSkillLevel.ADVANCED.ordinal()).createQuery();