如何解决不将 mongodb 文档 id 转换为 pojo 字段？

我正在从 mongodb 检索一些文档，然后将该文档转换为 json。生成的json如下

{"_id": {"$oid": "60f84fc822818919d59e3ad2"},"Metadata": [{"country": "USA","authors": [{"author": "Ayn Rand","books": [{"name": "The Fountainhead","code": "TFH"}]}]}]}

我创建了一个 POJO 来解析它，其他所有内容都被正确解析，但“_id”部分没有被解析。任何建议为什么它没有被解析？

以下是我的 POJO

import com.fasterxml.jackson.annotation.JsonProperty;

public class MetadataCollection {
    @JsonProperty("_id")
    private MetadataId id;

    private List<Metadata> Metadata;

    public MetadataId getId() {
        return id;
    }

    public void setId(MetadataId id) {
        this.id = id;
    }

    public List<Metadata> getMetadata() {
        return Metadata;
    }

    public void setMetadata(List<Metadata> Metadata) {
        this.Metadata = Metadata;
    }
}

和

import com.fasterxml.jackson.annotation.JsonProperty;

public class MetadataId {
    @JsonProperty("$oid")
    private String id;

    public String getId() {
        return id;
    }

    public void setId(String id) {
        this.id = id;
    }
}

我尝试使用“id”、“@Id”、“$oid”以及来自其他答案 like this 的一些建议。我使用的方法如下

public List<MetadataCollection> getAuthorsMetadata() {
        Gson gson = new Gson();
        MongoCollection<Document> MetadataCollection = mDatabase.getCollection("authors_Metadata");
        MongoCursor<Document> findIterableDocuments = MetadataCollection.find().cursor();

        List<MetadataCollection> returnMetadata = new ArrayList<>();
        while (findIterableDocuments.hasNext()) {
            Document currentDocument = findIterableDocuments.next();

            String jsonString = currentDocument.toJson();

            MetadataCollection Metadata = gson.fromJson(jsonString,MetadataCollection.class);

            returnMetadata.add(Metadata);
        }
        mongoClient.close();
        return returnMetadata;
    }

解决方法

暂无找到可以解决该程序问题的有效方法，小编努力寻找整理中！

如果你已经找到好的解决方法，欢迎将解决方案带上本链接一起发送给小编。

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var document = new BsonDocument{
{ "$where","this.StarTime!=this.EndTime"},
{ "Closed",1},
{ "StarTime",new BsonDocument("$gte",request.Stime)},
{ "EndTime",new BsonDocument("$lte",request.Etime)},
{ "TotalSecond",new BsonDocument(para,request.TotalMin * 60)}
};
var list= collection.Find(document);

var document = new BsonDocument{
{ "$where","this.StarTime-this.EndTime>10"},
{ "Closed",1},
{ "StarTime",new BsonDocument("$gte",request.Stime)},
{ "EndTime",new BsonDocument("$lte",request.Etime)},
{ "TotalSecond",new BsonDocument(para,request.TotalMin * 60)}
};
var list= collection.Find(document);

  @Getter
  @AllArgsConstructor
  public class O {
    private Set<String> abc;

  }

  @Test
  void test() throws Exception {

    Map map = new ObjectMapper().convertValue(new O(Set.of("abc","def")),Map.class);
    assertFalse(List.class.isAssignableFrom(map.get("abc").getClass())); // Already fails
    assertTrue(Set.class.isAssignableFrom(map.get("abc").getClass()));
  }

<dependency>
    <groupId>org.mongodb</groupId>
    <artifactId>mongodb-driver</artifactId>
    <version>3.8.0</version>
</dependency>

public class DiagnoseDocument {
    private ObjectId id;
    private String time;
    private String instance;
    private ArrayList<DiagnsoeResult> result;
}


public class DiagnsoeResult {
    private String instance_name;
    private String rule_name;
    private String problem_level;
    private String problem_name;
    private String problem_detail;
    private String advice;
}

//复制集连接MongoDB
String uriString = getURIString(primary);
// 需要针对对象中的类型设置Codec
CodecProvider pojoCodecProvider = PojoCodecProvider.builder().register(DiagnoseDocument.class, DiagnsoeResult.class).build();
CodecRegistry pojoCodecRegistry = fromRegistries(fromCodecs(new StringCodec(), new ObjectIdCodec(), new BsonArrayCodec()), fromProviders(pojoCodecProvider));
MongoClient mongoClient = new MongoClient(new MongoClientURI(uriString));
MongoDatabase database = mongoClient.getDatabase("mydb");
//对Collection中的类型设置Codec
MongoCollection<DiagnoseDocument> collection = database.getCollection("soar", DiagnoseDocument.class).withCodecRegistry(pojoCodecRegistry);
collection.insertOne(diagnoseDocument);