android - 如何使用 Gson 显示来自 JSON 的数据

Question

我有 json 数据的 URL 链接，我在我的应用程序的 RecyclerView 中显示颜色名称、颜色代码等数据，形状数据除外。 如何显示形状数据？？？ 这是我的 Json 网址链接:https://raw.githubusercontent.com/ianbar20/JSON-Volley-Tutorial/master/Example-JSON-Files/Example-Array.JSON

这是我的 AboutTask 类

public class AboutTask extends AsyncTask<JSONObject, String, AboutResponse> {

OkHttpClient okHttpClient = new OkHttpClient();
Gson gson = new Gson();

@Override
protected AboutResponse doInBackground(JSONObject... params) {
    try {

        JSONObject jsonObject = params[0];

        //String url = "http://bitstobyte.in/api/about";
        String url = "https://raw.githubusercontent.com/ianbar20/JSON-Volley-Tutorial/master/Example-JSON-Files/Example-Array.JSON";

        Request request = new Request.Builder().url(url).build();

        Response response = okHttpClient.newCall(request).execute();

        if (!response.isSuccessful()) {
            Log.v("About_Answer", "About_Failed");
            throw new IOException("about_UnExpected Code" + response);
        }

        String strResponse = response.body().string();

        Log.e("about_strResponse", strResponse);

        AboutMainResponse[] aboutMainResponse = gson.fromJson(strResponse, AboutMainResponse[].class);

        //System.out.println(Arrays.toString(aboutMainResponse));

        System.out.println(aboutMainResponse);

        Log.e("aboutResp", "AboutResponse" + aboutMainResponse);
        return aboutMainResponse[0];

    } catch (NullPointerException e) {
        e.printStackTrace();
    } catch (IOException e) {
        Log.e("About_searchTask", e.toString());
    } catch (Exception e) {
        e.printStackTrace();
    }
    return null;
}

}

这是 About_Fragment

public class About_Fragment extends android.support.v4.app.Fragment {
JSONObject jsonObject;

private List<AboutData> aboutDataList = new ArrayList<>();
private RecyclerView recyclerView;
private AboutAdapter aboutAdapter;
public About_Fragment() {
    // Required empty public constructor
}

@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
    // Inflate the layout for this fragment

    View rootView = inflater.inflate(R.layout.fragment_about_,container,false);

    recyclerView = (RecyclerView)rootView.findViewById(R.id.recyclerView);

    //recyclerView.setLayoutManager(new LinearLayoutManager(getActivity()));

    recyclerView.setHasFixedSize(true);

    RecyclerView.LayoutManager mLayoutManager = new LinearLayoutManager(getActivity());
    recyclerView.setLayoutManager(mLayoutManager);
    //recyclerView.addItemDecoration(new DividerItemDecoration(getActivity(), DividerItemDecoration.VERTICAL_LIST));
    recyclerView.setItemAnimator(new DefaultItemAnimator());

    recyclerView.setAdapter(aboutAdapter);
    aboutAdapter = new AboutAdapter(aboutDataList,getContext());

    new AboutTask(){
        @Override
        protected void onPostExecute(AboutResponse aboutResponse) {
            if (aboutResponse != null && aboutResponse.colorArray != null && aboutResponse.colorArray.size() > 0) {
                //if (aboutResponse != null && aboutResponse.shapeArray != null & aboutResponse.shapeArray.size() > 0)

                    aboutDataList = aboutResponse.colorArray;

                    //aboutDataList = aboutResponse.shapeArray;

                    aboutAdapter = new AboutAdapter(aboutDataList, getContext());

                    recyclerView.setAdapter(aboutAdapter);
                }
                Log.i("resp", "onPostExecute");
            }
    }.execute(jsonObject);
    return rootView;
}
}

这是我的 AboutResponse 代码:

public class AboutResponse {

public List<AboutData> shapeArray;
public List<AboutData> colorArray;
}

这是 AboutMainResponse:

public class AboutMainResponse extends AboutResponse {

// public AboutResponse aboutResponse;

}

这是我的 AboutAdapter 代码:

public class AboutAdapter extends    RecyclerView.Adapter<AboutAdapter.MyViewHolder> {

private List<AboutData> aboutDataList;
private Context context;

public class MyViewHolder extends RecyclerView.ViewHolder {
    public TextView colorName;
    public ImageView nextArrowimage;
    public TextView hexaValue,title_three;
    private AboutData aboutData=null;

    public MyViewHolder(View view) {
        super(view);
        colorName = (TextView) view.findViewById(R.id.title_one);
        nextArrowimage = (ImageView)view.findViewById(R.id.about_NextArrow);
        hexaValue = (TextView) view.findViewById(R.id.title_two);
        title_three = (TextView)view.findViewById(R.id.title_three);
        view.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
            }
        });
    }
}


public AboutAdapter(List<AboutData> aboutDataList,Context context) {
    this.aboutDataList = aboutDataList;
    this.context = context;
}

@Override
public MyViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
    View itemView = LayoutInflater.from(parent.getContext()).inflate(R.layout.list_items, parent, false);
    MyViewHolder holder = new MyViewHolder(itemView);
    return new MyViewHolder(itemView);
}

@Override
public void onBindViewHolder(final MyViewHolder holder, final int position) {
    final AboutData aboutData = aboutDataList.get(position);
    holder.hexaValue.setText(aboutData.getHexValue());
    holder.colorName.setText(aboutData.getColorName());
    holder.title_three.setText(aboutData.getShapeArray());

    holder.nextArrowimage.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {

            String colorName = aboutData.getColorName();
            String hexaValue = aboutData.getHexValue();
            Intent intent = new Intent(context,Display_Activity.class);
            intent.putExtra("colorName",colorName);
            intent.putExtra("hexaValue",hexaValue);
            context.startActivity(intent);

        }
    });
}
@Override
public int getItemCount() {
    return aboutDataList.size();
}

}

Answer 1

为您的 json 数据创建 Pojo 以使用 gson 进行解析，如下所示:

package com.example;

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

public class ColorArray {

@SerializedName("colorName")
@Expose
private String colorName;
@SerializedName("hexValue")
@Expose
private String hexValue;

public String getColorName() {
return colorName;
}

public void setColorName(String colorName) {
this.colorName = colorName;
}

public String getHexValue() {
return hexValue;
}

public void setHexValue(String hexValue) {
this.hexValue = hexValue;
}

}

---------------------------------com.example.Example.java----- ------------------------------

package com.example;

import java.util.List;
import com.google.gson.annotations.Expose;
import com.google.gson.annotations.SerializedName;

public class Example {

@SerializedName("colorArray")
@Expose
private List<ColorArray> colorArray = null;
@SerializedName("shapeArray")
@Expose
private List<ShapeArray> shapeArray = null;

public List<ColorArray> getColorArray() {
return colorArray;
}

public void setColorArray(List<ColorArray> colorArray) {
this.colorArray = colorArray;
}

public List<ShapeArray> getShapeArray() {
return shapeArray;
}

public void setShapeArray(List<ShapeArray> shapeArray) {
this.shapeArray = shapeArray;
}

}

------------------------------------com.example.ShapeArray.java------ ------------------------------

package com.example;

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

public class ShapeArray {

@SerializedName("shapeName")
@Expose
private String shapeName;

public String getShapeName() {
return shapeName;
}

public void setShapeName(String shapeName) {
this.shapeName = shapeName;
}

}

您可以通过以下链接在线为您的json数据生成pojos:

http://www.jsonschema2pojo.org/

像下面的代码一样，您可以解析您的数据并获得具有以颜色和形状列表形式解析数据的示例类对象。

然后你将这个列表设置到 Listview 和 RecyclerView

Gson gson = new Gson();
Type listType = new TypeToken<List<Example>>(){}.getType();
List<Example> details = gson.fromJson(response, listType);