解析json响应android改造

Question

我正在尝试解析Android Studio中服务器的响应。 但是我没有在Arraylist中获得所有值。

我已经创建了ItemData.java和ItemResponse.java

我正在使用getItemData方法调用Api：

public void getItemData() {
        Call<ItemDataResponse> call = service.getData(token, "200");
        call.enqueue(new Callback<ItemDataResponse>() {
            @Override
            public void onResponse(@NonNull Call<ItemDataResponse> call, @NonNull Response<ItemDataResponse> response) {

                Log.d("dataFromServer", response.body.toString());

            }

            @Override
            public void onFailure(@NonNull Call<ItemDataResponse> call, @NonNull Throwable t) {
                progressDoalog.dismiss();
                Toast.makeText(LiveVehiclesActivity.this, "Something went wrong...Please try later!", Toast.LENGTH_SHORT).show();
            }
        });
    } 

这是Json的回应：

{
   "code":"1",
   "items":[
      {
         "item_id":"200",
         "speed":"2"
      },
      {
         "item_id":"201",
         "speed":"0"
      }
   ]
}

ItemsResponse.java：

public class ItemDataResponse implements Serializable {
    @SerializedName("code")
    private String code;

    @SerializedName("items")
    @Expose
    private List<ItemData> items;



    public String getResponsecode() {
        return responsecode;
    }

    public void setResponsecode(String responsecode) {
        this.responsecode = responsecode;
    }

    public List<ItemData> getItems() {
        return items;
    }

    public void setItems(List<ItemData> items) {
        this.items = items;
    }
}

ItemData.java

import com.google.gson.annotations.Expose;
import com.google.gson.annotations.SerializedName;

public class ItemData {

@SerializedName("item_id")
@Expose
private String itemId;
@SerializedName("speed")
@Expose
private String speed;

public String getItemId() {
return itemId;
}

public void setItemId(String itemId) {
this.itemId = itemId;
}

public String getSpeed() {
return speed;
}

public void setSpeed(String speed) {
this.speed = speed;
}

}

在调试模式下运行后，我得到如下响应：

code:"1"
items=null

Answer 1

您应该修改

class ItemData {
    private String item_id;
    private String speed;

    public String getItem_id() {
        return item_id;
    }

    public void setItem_id(String item_id) {
        this.item_id = item_id;
    }

    public String getSpeed() {
        return speed;
    }

    public void setSpeed(String speed) {
        this.speed = speed;
    }
}

Answer 2

ItemData模型似乎与JSON响应不一致。 即

{
    "item_id":"200",
    "speed":"2"
}

应该映射到：

class ItemData implements Serializable {

    @SerializedName("item_id")
    private String itemId;

    @SerializedName("speed")
    private String speed;

    // getters and setters

}

Answer 3

对于包含“ _”的字段，请使用SerializedName属性。 在这里，您的ItemData类中的item_id在映射时遇到问题。

import com.google.gson.annotations.Expose;
import com.google.gson.annotations.SerializedName;

public class ItemData {

@SerializedName("item_id")
@Expose
private String itemId;
@SerializedName("speed")
@Expose
private String speed;

public String getItemId() {
return itemId;
}

public void setItemId(String itemId) {
this.itemId = itemId;
}

public String getSpeed() {
return speed;
}

public void setSpeed(String speed) {
this.speed = speed;
}

}

请同时更改您的ItemDataResponse类

public class ItemDataResponse {

@SerializedName("code")
@Expose
private String code;
@SerializedName("items")
@Expose
private List<Item> items = null;

public String getCode() {
return code;
}

public void setCode(String code) {
this.code = code;
}

public List<Item> getItems() {
return items;
}

public void setItems(List<Item> items) {
this.items = items;
}

}