JSON數據解析錯誤來自服務器的響應變為空：Android

Question

我正在嘗試從服務器獲取數據，然后將其顯示到應用程序中。

我有JSON數據，

{"COLUMNS":["TIMEID","BRANCHID","COMPANYID","MON_O","TUE_O","WED_O","THU_O","FRI_O","SAT_O","SUN_O","MON_C","TUE_C","WED_C","THU_C","FRI_C","SAT_C","SUN_C","CREATDATE"],"DATA":[[195,4,4,"09:00","09:00","09:00","09:00","09:00","Closed","Closed","16:30","16:30","16:30","16:30","16:30","Closed","Closed","May, 16 2017 08:16:12"]]}

我有JAVA課程，

public static final String MON_O  = "MON_O";
public static final String TUE_O = "TUE_O";
public static final String WED_O = "WED_O";
public static final String THU_O = "THU_O";
public static final String FRI_O = "FRI_O";
public static final String SAT_O = "SAT_O";
public static final String SUN_O = "SUN_O";

public static final String MON_C = "MON_C";
public static final String TUE_C = "TUE_C";
public static final String WED_C = "WED_C";
public static final String THU_C = "THU_C";
public static final String FRI_C = "FRI_C";
public static final String SAT_C = "SAT_C";
public static final String SUN_C = "SUN_C";

public static final String JSON_ARRAY = "COLUMNS";

private void getData() {
    String url = context.getString(site_url)+"branch_time.cfc?method=branchtime&branchid=" +dBranchID;

    StringRequest stringRequest = new StringRequest(url, new Response.Listener<String>() {

        @Override
        public void onResponse(String response) {
            showJSON(response);
        }
    },
            new Response.ErrorListener() {
                @Override
                public void onErrorResponse(VolleyError error) {
                    Toast.makeText(context,error.getMessage().toString(),Toast.LENGTH_LONG).show();
                }
            });

    RequestQueue requestQueue = Volley.newRequestQueue(context);
    requestQueue.add(stringRequest);
}

    private void showJSON(String response) {

    String name = "";

    try {
        JSONObject jsonObject = new JSONObject(response);
        Log.d("TAG", jsonObject.toString());
        JSONArray result = jsonObject.getJSONArray(JSON_ARRAY);

            Log.d("TAG", result.toString());
            JSONObject companyData = result.getJSONObject(0);
            name = companyData.getString(MON_O);
            Log.e(name,"datadtadattadtatadtat");
    } catch (JSONException e) {
        e.printStackTrace();
    }

    timeStatus.setText(name);

}

當我嘗試記錄服務器的響應時，我可以看到只有DATA值為null的COLUMNS值存在。 另外，我收到如下錯誤，

System.err: org.json.JSONException: Value TIMEID at 0 of type java.lang.String cannot be converted to JSONObject

為什么我要從服務器獲取DATA值為null以及如何解決該錯誤？ 我已經引用了以下鏈接： org.json.JSONException：類型java.lang.String的值不能轉換為JSONArray

解析數據org.json.JSONException時出錯：類型java.lang.String的值<br不能轉換為JSONObject

但是，這些對我來說似乎無濟於事。 有人可以幫忙嗎？

Answer 1

嘗試這個.....

JSONParser jsonParser = new JSONParser();
            jsonObject = jsonParser.getJSONFromUrl(url);

            try {
                user1 = jsonObject.getJSONArray("COLUMNS");

                for (int i = 0; i < user1.length(); i++) {
                    String value = (String) user1.get(i);

                    getList.add(value.toString());
                }
            } catch (JSONException e) {
                e.printStackTrace();
            }

Answer 2

我觀察到您的json響應 ，我認為無論您在列json數組中有什么，都沒有字符串，這就是為什么您會出錯的原因，

在您的響應中，沒有鍵值對，因此很容易獲得String。

所以你應該用getString（）而不是getJsonObject（）

private void showJSON(String response) {
    String name = "";
    try {
        JSONObject jsonObject = new JSONObject(response);
        Log.d("TAG", jsonObject.toString());
        JSONArray result = jsonObject.getJSONArray(JSON_ARRAY);
        Log.d("TAG", result.toString());
        name = result.getString(index);
        Log.e(name,"datadtadattadtatadtat");
    } catch (JSONException e) {
        e.printStackTrace();
    }

index基本上是json數組索引，您可以將其設置為0或其他值，並根據需要進行循環 。