Question

我正在与Strongloop / Loopback一起开发Android应用程序。我已将数据存储在MySQL数据库中，并且使用Strongloop / Loopback进行映射时没有问题。但是，使用Strongloop / Loopback从数据库中检索值时，列表始终返回一个大小但值为null的列表。无法弄清楚出了什么问题。任何人都可以帮我吗？非常感谢:)）

这是我从Strongloop访问时对数据库的json响应：

[
  {
"rewards_image_name": "http://x.x.x.x/projects/images/rewards_1.png",
"rewards_equivalent_points": "10",
"id": 1 }, {
"rewards_image_name": "http://x.x.x.x/projects/images/rewards_2.png",
"rewards_equivalent_points": "20",
"id": 2 }, {
"rewards_image_name": "http://x.x.x.x/projects/images/rewards_3.png",
"rewards_equivalent_points": "30",
"id": 3 }, {
"rewards_image_name": "http://x.x.x.x/projects/images/rewards_4.png",
"rewards_equivalent_points": "40",
"id": 4 }
]

以下是获取列表的代码：

    StrongloopClient strongloopClient = new StrongloopClient(this.context);
    RestAdapter adapter = strongloopClient.getLoopBackAdapter("Rewards", "GET");
    StrongloopRewardsModelRepository strongloopRewardsModelRepository = adapter.createRepository(StrongloopRewardsModelRepository.class);       
    strongloopRewardsModelRepository.findAll(new ListCallback<StrongloopRewardsModel>() {

        @Override
        public void onSuccess(List<StrongloopRewardsModel> arg0) {
            Log.e("", "GetAllRewards success:  " + arg0.get(0).getEquivalentPoints());

        }

        @Override
        public void onError(Throwable arg0) {
            Log.e("", "GetAllRewards error: " + arg0);
        }
    });

这是StrongloopClient：

public class StrongloopClient {

private Context context;
private RestAdapter adapter;

public StrongloopClient(Context contxt) {
    context = contxt;
}

    public RestAdapter getLoopBackAdapter(String transaction, String operation) {
    if (adapter == null) {
        adapter = new RestAdapter(context, "http://192.168.44.101:3000/api");
        adapter.getContract().addItem(
                new RestContractItem("/" + transaction, operation),
                transaction);
    }
    return adapter;
}

以下是存储库的代码：

public class StrongloopRewardsModelRepository extends ModelRepository<StrongloopRewardsModel>{

public StrongloopRewardsModelRepository() {
    super("Rewards", "Rewards", StrongloopRewardsModel.class);  
    }
}

这是模特：

public class StrongloopRewardsModel extends Model {

private Integer rewardsImageId;
private String rewardImageName;
private String equivalentPoints;

public Integer getRewardsImageId() {
    return rewardsImageId;
}
public void setRewardsImageId(Integer rewardsImageId) {
    this.rewardsImageId = rewardsImageId;
}
public String getRewardImageName() {
    return rewardImageName;
}
public void setRewardImageName(String rewardImageName) {
    this.rewardImageName = rewardImageName;
}
public String getEquivalentPoints() {
    return equivalentPoints;
}
public void setEquivalentPoints(String equivalentPoints) {
    this.equivalentPoints = equivalentPoints;
}
}

Answer 1

最后，我发现了什么是错的。 POJO应该与models.json中创建的模型的字段匹配。谢谢你的时间。

但是，我的另一个问题是，当我使用过滤器进行查询时，例如将过滤器作为传递给Strongloop适配器的“参数”的一部分传递，它似乎返回所有模型实例而不是过滤的模型实例。我的问题中的代码相同，只是getLoopbackAdapter（“Rewards”，“GET”）变为“Rewards？filter [where] [rewards_equivalent_points] = 10”，“GET”）。任何想法为什么它表现如此？谢谢:)）

Answer 2

这是因为您的搜索没有找到任何实例。我不确定您是否需要在您的应用上处理此问题，或者SDK是否需要处理此问题。

例如，当尝试通过rest接口按元素[1]进行搜索时，它会转换为404（未找到）：rest：{after：convertNullToNotFoundError}

https://github.com/strongloop/loopback-datasource-juggler/blob/master/lib/dao.js#L771

Strongloop / Loopback findAll功能返回null

2 个答案: