E/排球：com.android.volley.ParseError：org.json.JSONException

Question

我正在嘗試從 API 網頁中讀取 JSON 字符串，但收到 org.json.JSONObject 類型的錯誤 jsonexception 無法轉換為 JSONArray。

package com.kedaiit.dev.jadwalin;

import android.app.ProgressDialog;
import android.os.Bundle;
import android.support.annotation.NonNull;
import android.support.annotation.Nullable;
import android.support.v4.app.Fragment;
import android.support.v7.widget.DividerItemDecoration;
import android.support.v7.widget.LinearLayoutManager;
import android.support.v7.widget.RecyclerView;
import android.util.Log;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.LinearLayout;

import com.android.volley.RequestQueue;
import com.android.volley.Response;
import com.android.volley.VolleyError;
import com.android.volley.toolbox.JsonArrayRequest;
import com.android.volley.toolbox.Volley;

import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;

import java.util.ArrayList;
import java.util.List;

public class UpcomingFragment extends Fragment {

    private RecyclerView recyclerView;

    private LinearLayoutManager linearLayoutManager;
    private DividerItemDecoration dividerItemDecoration;
    private List<Upcoming> list;
    private RecyclerView.Adapter adapter;

    private String url = "https://www.thesportsdb.com/api/v1/json/1/eventsnextleague.php?id=4328";


    public UpcomingFragment() {
        // Required empty public constructor
    }

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
                             Bundle savedInstanceState) {

        View view = inflater.inflate(R.layout.fragment_upcoming, container, false);

        recyclerView = view.findViewById(R.id.recyclerViewUpcoming);

        list = new ArrayList<>();
        adapter = new UpcomingAdapter(getContext(), list);

        linearLayoutManager = new LinearLayoutManager(getContext());
        linearLayoutManager.setOrientation(LinearLayoutManager.VERTICAL);
        dividerItemDecoration = new DividerItemDecoration(recyclerView.getContext(), linearLayoutManager.getOrientation());

        recyclerView.setHasFixedSize(true);
        recyclerView.setLayoutManager(linearLayoutManager);
        recyclerView.addItemDecoration(dividerItemDecoration);
        recyclerView.setAdapter(adapter);

        getData();

        return view;
    }

    private void getData() {
        final ProgressDialog progressDialog = new ProgressDialog(getContext());
        progressDialog.setMessage("Loading...");
        progressDialog.show();

        JsonArrayRequest jsonArrayRequest = new JsonArrayRequest(url, new Response.Listener<JSONArray>() {
            @Override
            public void onResponse(JSONArray response) {
                for (int i = 0; i < response.length(); i++) {
                    try {
                        JSONObject jsonObject = response.getJSONObject(i);

                        Upcoming obj = new Upcoming();
                        obj.setIdEvent(jsonObject.getString("idEvent"));
                        obj.setStrEvent(jsonObject.getString("strEvent"));
                        obj.setDateEvent(jsonObject.getString("dateEvent"));


                        list.add(obj);
                    } catch (JSONException e) {
                        e.printStackTrace();
                        progressDialog.dismiss();
                    }
                }
                adapter.notifyDataSetChanged();
                progressDialog.dismiss();
            }
        }, new Response.ErrorListener() {
            @Override
            public void onErrorResponse(VolleyError error) {
                Log.e("Volley", error.toString());
                progressDialog.dismiss();
            }
        });
        RequestQueue requestQueue = Volley.newRequestQueue(getContext());
        requestQueue.add(jsonArrayRequest);
    }

}

https://github.com/bellabeen/Android_Jadwalin This project me get this in the logcat and when i debug it says: jsonexception of type E/Volley: com.android.volley.ParseError: org.json.JSONException:

Answer 1

JSONObject 和 JSONArray 的區別

Json Object 包含在 {}
eg: { "name": "Ramu", "age": "21"}

Json 數組包含在 [] 內
eg: [{ "name": "Ramu", "age": "21"}, { "name": "Arnav", "age": "12"}]

---

你的情況

你的 Json 結構

您的 Object 名稱是events ，因此您需要使用events作為 id 從 JSONObject 獲取 JSONArray

JSONArray jsonArray = response.getJSONArray("事件");

然后遍歷 json 對象數組。

for (int i = 0; i < jsonArray.length(); i++) {

    JSONObject Jobj = jsonArray.getJSONObject(i);

    \\You can read each object using Jobj now

}

傳遞給 Volley 請求的參數錯誤，需要指定 url 調用的 GET 或 POST 方法。 檢查下面的代碼。

正確的代碼應該是

package com.kedaiit.dev.jadwalin;

import android.app.ProgressDialog;
import android.os.Bundle;
import android.support.annotation.NonNull;
import android.support.annotation.Nullable;
import android.support.v4.app.Fragment;
import android.support.v7.widget.DividerItemDecoration;
import android.support.v7.widget.LinearLayoutManager;
import android.support.v7.widget.RecyclerView;
import android.util.Log;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.LinearLayout;

import com.android.volley.Request;
import com.android.volley.RequestQueue;
import com.android.volley.Response;
import com.android.volley.VolleyError;
import com.android.volley.toolbox.JsonArrayRequest;
import com.android.volley.toolbox.JsonObjectRequest;
import com.android.volley.toolbox.Volley;

import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;

import java.util.ArrayList;
import java.util.List;

public class UpcomingFragment extends Fragment {

    private RecyclerView recyclerView;

    private LinearLayoutManager linearLayoutManager;
    private DividerItemDecoration dividerItemDecoration;
    private List<Upcoming> list;
    private RecyclerView.Adapter adapter;

    private String url = "https://www.thesportsdb.com/api/v1/json/1/eventsnextleague.php?id=4328";


    public UpcomingFragment() {
        // Required empty public constructor
    }

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
                             Bundle savedInstanceState) {

        View view = inflater.inflate(R.layout.fragment_upcoming, container, false);

        recyclerView = view.findViewById(R.id.recyclerViewUpcoming);

        list = new ArrayList<>();
        adapter = new UpcomingAdapter(getContext(), list);

        linearLayoutManager = new LinearLayoutManager(getContext());
        linearLayoutManager.setOrientation(LinearLayoutManager.VERTICAL);
        dividerItemDecoration = new DividerItemDecoration(recyclerView.getContext(), linearLayoutManager.getOrientation());

        recyclerView.setHasFixedSize(true);
        recyclerView.setLayoutManager(linearLayoutManager);
        recyclerView.addItemDecoration(dividerItemDecoration);
        recyclerView.setAdapter(adapter);

        getData();

        return view;
    }

    private void getData() {
        final ProgressDialog progressDialog = new ProgressDialog(getContext());
        progressDialog.setMessage("Loading...");
        progressDialog.show();

        JsonObjectRequest my_request = new JsonObjectRequest(Request.Method.GET, url, null, new Response.Listener<JSONObject>() {
            @Override
            public void onResponse(JSONObject response) {
            try{
                JSONArray jsonArray = response.getJSONArray("events");
                for (int i = 0; i < jsonArray.length(); i++) {

                        JSONObject Jobj = jsonArray.getJSONObject(i);

                        Upcoming obj = new Upcoming();
                        obj.setIdEvent(Jobj.getString("idEvent"));
                        obj.setStrEvent(Jobj.getString("strEvent"));
                        obj.setDateEvent(Jobj.getString("dateEvent"));


                        list.add(obj);

                }
                } catch (JSONException e) {
                    e.printStackTrace();
                    progressDialog.dismiss();
                }
                adapter.notifyDataSetChanged();
                progressDialog.dismiss();
            }
        }, new Response.ErrorListener() {

            @Override
            public void onErrorResponse(VolleyError error) {
                Log.e("Volley", "Error: " + error.getMessage());
                progressDialog.dismiss();
            }
        });



        RequestQueue requestQueue = Volley.newRequestQueue(getContext());
        requestQueue.add(my_request);
    }

}

---

當前代碼的 Output

希望這可以幫助，
謝謝你