Morphia 2.0.0-RC1查询在我保存了一个对象后返回空列表。

Question

我正试图让Morphia与mongoDB一起工作，并且能够将我的对象保存到数据库中。但是当我试图检索所有对象时，我得到的是一个空列表。

我使用的是mongo db java driver 3.12.0和Morphia 2.0.0-rc1。旧的execute方法从2.0开始就被废弃了，但是参考指南没有更新。我看了一下github上的代码，直接调用iterator而不是使用execute before似乎是现在正确的方法。

更新：通过添加任何过滤器，我得到了结果？

public class MongoDBConnectorTest {
@Test
public void test() {
    //MongoDatabase db = MongoDBConnector.getClient().getDatabase("lottoDB");
    //MongoCollection<Lotto> lottoCollection = db.getCollection("lotto", Lotto.class);

    Datastore lottoDatastore = LottoDataStore.getLottoDataStore().getDataStore();

    //System.out.println(db.getName());

    final Lotto lotto = new Lotto();
    lotto.setHighestPriceMoney(100000);

    // Insert lotto object
    //lottoCollection.insertOne(lotto);
    lottoDatastore.save(lotto);

    // Find it again
    //final Query<Lotto> query = lottoDatastore.find(Lotto.class);
    //List<Lotto> lottos = (List<Lotto>) query.iterator().toList();
    final Query<Lotto> query = lottoDatastore.find(Lotto.class);
    final List<Lotto> lottos = query.iterator().toList();
    final Lotto lotto2 = query.first();
    //Lotto lotto2 = query.first();

    System.out.println("Lotto found:");
    System.out.println(lottos.size());
    System.out.println(lotto2);

}
}

LottoDataStore.java

public class LottoDataStore {
private static LottoDataStore lottoDataStore = null;
protected final Datastore datastore;

public static LottoDataStore getLottoDataStore() {
    if(lottoDataStore == null) lottoDataStore = new LottoDataStore();

    return lottoDataStore;
}

private LottoDataStore() {
    this.datastore = Morphia.createDatastore(MongoDBConnector.getClient().getMongoClient(), "lottoDB");
    // tell Morphia where to find your classes
    // can be called multiple times with different packages or classes
    datastore.getMapper().mapPackage("com.j.productdata.model.entity.lotto");
    datastore.ensureIndexes();
}

public Datastore getDataStore() {
    return datastore;
}

}

Lotto.java

@Entity("lotto")
public class Lotto {
@Id
protected String alias = "lotto";

@BsonProperty(value = "highest_price_money")
protected int highestPriceMoney;

@BsonProperty(value = "average_price_money")
protected int averagePriceMoney;

@BsonProperty(value = "min_cost")
protected int minCost;

@BsonProperty(value = "min_cost_highest_price_money")
protected int minCostHighestPriceMoney;

List<LottoResult> results;

public Lotto() {

}

public String getAlias() {
    return alias;
}



public void setAlias(String alias) {
    this.alias = alias;
}



public int getHighestPriceMoney() {
    return highestPriceMoney;
}



public void setHighestPriceMoney(int highestPriceMoney) {
    this.highestPriceMoney = highestPriceMoney;
}



public int getAveragePriceMoney() {
    return averagePriceMoney;
}



public void setAveragePriceMoney(int averagePriceMoney) {
    this.averagePriceMoney = averagePriceMoney;
}



public int getMinCost() {
    return minCost;
}



public void setMinCost(int minCost) {
    this.minCost = minCost;
}



public int getMinCostHighestPriceMoney() {
    return minCostHighestPriceMoney;
}



public void setMinCostHighestPriceMoney(int minCostHighestPriceMoney) {
    this.minCostHighestPriceMoney = minCostHighestPriceMoney;
}



public List<LottoResult> getResults() {
    return results;
}



public void setResults(List<LottoResult> results) {
    this.results = results;
}



@Override
public String toString() {
    return "Lotto [id=" + alias + ", highestPriceMoney=" + highestPriceMoney + ", minCost=" + minCost
            + ", minCostHighestPriceMoney=" + minCostHighestPriceMoney + ", results=" + results + "]";
}


}

Answer 1

这对我来说，使用 复制者 和2.0.0-RC1。 我不太清楚是什么原因导致你没有看到结果。 不过，代码中也有一些奇怪的地方。 你的代码里有很多驱动注释。 就目前而言，这很好，但Morphia并没有使用这些注释。

这可能是你映射的包与 Lotto 寿命，但我希望得到一个关于缺失的信息的错误。Codec 在这种情况下，。