Question

我正在尝试将我的数据从localhost读取到Android Studio。我用排球来做到这一点。我有问题从我的json获取值。这是我的json。

{"studentList":[{"username":"2011089882","password":"","section":"c4a","year":"4th"}]}

这是Android中的代码。

JsonObjectRequest jsonObjReq = new JsonObjectRequest(urlJsonObj, null, new Response.Listener<JSONObject>() {
        @Override
        public void onResponse(JSONObject response) {
            Log.d(TAG, response.toString());

            try {
                String username = response.getString("username");
                String section = response.getString("section");
                String year = response.getString("year");

                jsonResponse = "";
                jsonResponse += "Username: " + username + "\n\n";
                jsonResponse += "Section: " + section + "\n\n";
                jsonResponse += "Year: " + year + "\n\n\n";

                txtView.setText(jsonResponse);

            } catch (JSONException e) {
                e.printStackTrace();
                Toast.makeText(getApplicationContext(),
                        "Error: " + e.getMessage(),
                        Toast.LENGTH_LONG).show();
            }
            hidepDialog();
        }
    }, new Response.ErrorListener() {

        @Override
        public void onErrorResponse(VolleyError error) {
            VolleyLog.d(TAG, "Error: " + error.getMessage());
            Toast.makeText(getApplicationContext(),
                    error.getMessage(), Toast.LENGTH_SHORT).show();
        }
    });

    // Adding request to request queue
    AppController.getInstance().addToRequestQueue(jsonObjReq);
}

感谢您的帮助。

Answer 1

 try {
    JSONObject jsonObject = new JSONObject(response.toString());
    JSONArray jsonArray = jsonObject.getJSONArray("studentList");
    for (int i = 0; i < jsonArray.length(); i++) {
        JSONObject jsonObject1 = jsonArray.getJSONObject(i);
        String username = jsonObject1.getString("username");
        String section = jsonObject1.getString("section");
        String year = jsonObject1.getString("year");
        Toast.makeText(MainActivity.this, username + " " + section + " " + year, Toast.LENGTH_SHORT).show();
    }
} catch (JSONException e) {
    e.printStackTrace();
}

希望这有帮助

Answer 2

{"studentList":[{"username":"2011089882","password":"","section":"c4a","year":"4th"}]}

JSON响应的结构是一个包含列表的Object，其中包含student类型的对象其中包含用户名和＆amp;密码，您直接尝试从外部对象获取用户名。

String username = response.getString("username");

首先，您需要从列表中提取对象，然后访问用户名。

JsonArray jsonArr = response.getJSONArray("studentList");
JsonObject studentObj = jsonArr.get(0);

Answer 3

    JSONArray parentArray = response.getJSONArray("studentList");
    if (parentArray.length() == 0) {
        //no students
    } else {
        for (int i = 0; i < parentArray.length(); i++) {
            JSONObject finalObject = parentArray.getJSONObject(i);

            String username = finalObject.getString("username");
            String password = finalObject.getString("password");
            String section = finalObject.getString("section");
            String year = finalObject.getString("year");
        }
    }

这将循环遍历＆＃34; studentList＆＃34;

中的每个学生

确保导入JSONArray import org.json.JSONArray;

在Android中获取带ID的JSONObject

3 个答案: