Criteria.byExample return a "_class" condition

[V0idk]

here is my code:

    @Test
    void testCount() throws IOException {
        Example<FileChange> example = Example.of(FileChange.builder().programmingLanguage("Python").build());
        Query query = new Query(Criteria.byExample(example));
        List<FileChange> bad = mongoTemplate.find(query, FileChange.class); // not working, return empty

        Query query1 = new Query();
        query1.addCriteria(Criteria.where("programming_language").is("Python"));
        List<FileChange> good = mongoTemplate.find(query1, FileChange.class);       
}

// relative object

@Data
@AllArgsConstructor
@NoArgsConstructor
@Builder
@Document("file_change")
public class FileChange {

    @Id
    private ObjectId id;

    @Field("file_change_id")
    private String fileChangeId;

    @Field("hash")
    private String hash;

    @Field("filename")
    private String filename;

    @Field("old_path")
    private String oldPath;

    @Field("new_path")
    private String newPath;

    @Field("change_type")
    private String changeType;

    @Field("diff")
    private String diff;

    @Field("num_lines_added")
    private String numLinesAdded;

    @Field("num_lines_deleted")
    private String numLinesDeleted;

    @Field("code_after")
    private String codeAfter;

    @Field("code_before")
    private String codeBefore;

    @Field("nloc")
    private String nloc;

    @Field("complexity")
    private String complexity;

    @Field("token_count")
    private String tokenCount;

    @Field("programming_language")
    private String programmingLanguage;
}

[christophstrobl]

Thanks for getting in touch. Please do not post images here but take the time to provide a complete minimal sample (something that we can unzip or git clone, build, and deploy) that reproduces the problem. Thank you.

[V0idk]

bad command:
{
    "find": "file_change",
    "filter": {
        "programming_language": "Python",
        "_class": {
            "$in": [
                "xxx.analysis.infrastructure.persist.mongo.po.FileChange"
            ]
        }
    },
    "$db": "gts",
    "lsid": {
        "id": {
            "$binary": {
                "base64": "bJQRN0tNRxWfh0ITGqj2ZA==",
                "subType": "04"
            }
        }
    }
}

good command:
{
    "find": "file_change",
    "filter": {
        "programming_language": "Python"
    },
    "$db": "gts",
    "lsid": {
        "id": {
            "$binary": {
                "base64": "bJQRN0tNRxWfh0ITGqj2ZA==",
                "subType": "04"
            }
        }
    }
}

[V0idk]

I find the follow code add "_class" to condition:

    private Document updateTypeRestrictions(Document query, Example<?> example) {
        Document result = new Document();
        if (this.isTypeRestricting(example)) {
            result.putAll(query);
            **this.converter.getTypeMapper().writeTypeRestrictions(result, this.getTypesToMatch(example));** 
            return result;
        } else {
            Iterator var4 = query.entrySet().iterator();

            while(var4.hasNext()) {
                Map.Entry<String, Object> entry = (Map.Entry)var4.next();
                if (!this.converter.getTypeMapper().isTypeKey((String)entry.getKey())) {
                    result.put((String)entry.getKey(), entry.getValue());
                }
            }

[V0idk]

after change code to, it works

 Example<FileChange> example = Example.of(FileChange.builder().programmingLanguage("Python").build(), UntypedExampleMatcher.matching());

I think it's a bug the framwork add updateTypeRestrictions default, no doc have point that

[christophstrobl]

Glad it works for you now.
Query by Example, its behaviour as well as the UntypedExampleMatcher are described in the reference documentation.