Question

这是我的JSON响应，我将该响应存储到模型类

中

 JsonObjectRequest jsonbObjReq_parents_Child = new JsonObjectRequest(Request.Method.GET, "http://qnabubackend-env.2fuz4eh5jh.ap-south-1.elasticbeanstalk.com/parent/api/get/childs/"+user_id, null,
            new Response.Listener<JSONObject>()
            {
                @Override
                public void onResponse(JSONObject response)
                {
                    try
                    {
                        Boolean error = response.getBoolean("error");
                        JSONArray jsonArray = response.getJSONArray("response");
                        int size = jsonArray.length();
                        Log.e("HEy>>>>",""+size);
                        for (int i=0;i<jsonArray.length();i++)
                        {
                            Log.e("H>>>>",""+size);
                            JSONObject jsonObject = jsonArray.getJSONObject(i);
                            DataSet dataSet = new DataSet();
                            dataSet.setStudentId(jsonObject.getInt("id"));
                            dataSet.setStudentFirstName(jsonObject.getString("studentFirstName"));
                            dataSet.setStudentLastName(jsonObject.getString("studentLastName"));
                            dataSet.setStudentclassId(jsonObject.getInt("classId"));
                            dataSet.setStudentCurClass(jsonObject.getInt("currentClass"));
                            dataSet.setStudentCurClassSec(jsonObject.getString("currentClassSection"));
                            dataSet.setStudentMobileNum(jsonObject.getLong("phoneNumber"));
                            dataSet.setStudentSchoolId(jsonObject.getInt("schoolId"));
                            dataSet.setSessionYear(jsonObject.getString("sessionYear"));

                            JSONArray jsonArray1 = jsonObject.getJSONArray("subjects");

                            List<DataSet.SubjectsList> subjectsLists = new ArrayList<>();

                            int j;

                            for (j=0;j<jsonArray1.length();j++)
                            {
                                JSONObject jsonObject1 = jsonArray1.getJSONObject(j);
                                DataSet.SubjectsList dataSubjects = new DataSet.SubjectsList();
                                dataSubjects.setSubjectId(jsonObject1.getInt("id"));
                                dataSubjects.setSubjectsName(jsonObject1.getString("name"));
                                subjectsLists.add(dataSubjects);

                            }

                            dataSet.setSubjectsLists(subjectsLists);

                            childData.add(dataSet);

                        }

childData是我的arraylist，它是通用的，即：DataSet 现在我想在另一个活动中访问像schoolId，sessionYear这样的数据。

public class AnnualActivity {

JsonObjectRequest jsonbObjReq_parents_Child = new JsonObjectRequest(Request.Method.GET, "http://qnabubackend-env.2fuz4eh5jh.ap-south-1.elasticbeanstalk.com/school/api/annual/activity/get/list?schoolId="+schoolID+"&session="+sessionYear, null,

}

这不是下一个活动所以我不能使用INTENTS Concept。

如果我喜欢这个我在AnnualActivity Class中得到NullPointerException

 private List sharedPref(List<DataSet> data)
    {

        for (int i=0;i<data.size();i++)
        {
            DataSet dataSet = data.get(i);
            int a = dataSet.getStudentSchoolId();
            String b = dataSet.getSessionYear();

            Log.e("grrf",""+a);
            Log.e("fasfc",b);
        }

        return data;
    }

Answer 1

创建方法

private List sharedPref(List<DataSet> data)
{

    for (int i=0;i<data.size();i++)
    {
        DataSet dataSet = data.get(i);
        int a = dataSet.getStudentSchoolId();
        String b = dataSet.getSessionYear();
        getJsonRequest(a+"" , b);
        Log.e("grrf",""+a);
        Log.e("fasfc",b);
    }

    return data;
}

 public void getJsonRequest(String schoolID, String sessionYear){
    JsonObjectRequest jsonbObjReq_parents_Child = new JsonObjectRequest(Request.Method.GET, "http://qnabubackend-env.2fuz4eh5jh.ap-south-1.elasticbeanstalk.com/school/api/annual/activity/get/list?schoolId="+schoolID+"&session="+sessionYear, null);

}

从循环调用此方法并返回循环。

Answer 2

您可以将该ArrayList存储在sharedPreference中，如

  SharedPreferences preferences = Utils.getGCMPreferences(context);
     SharedPreferences.Editor editor = preferences.edit();
      editor.putString("key", new Gson().toJson(list));
       editor.commit();

list是您的Model类类型

无论你想在哪里使用它，都可以像

一样

ModelClass model = null;
   SharedPreferences preferences = getGCMPreferences(context);
   String data = preferences.getString("key", null);

   model = new Gson().fromJson(data,ModelClass.class);

Answer 3

在“api课程”中有一个简单的方法

public static void getChilds(final String user_id,  Response.Listener<JSONObject> res) {
    String baseUrl = "http://qnabubackend-env.2fuz4eh5jh.ap-south-1.elasticbeanstalk.com/parent/api";
    JsonObjectRequest req = new JsonObjectRequest(Request.Method.GET, baseUrl + "/get/childs/"+user_id, null,
        res);
    // TODO: add request to Volley queue
}

在您的活动中，您将致电

API.getChilds(id, new Response.Listener<JSONObject>()
        {
            @Override
            public void onResponse(JSONObject response)
            {
                 // Parse the response here 
                 // Update your Activity data

如何从另一个活动中的Model类中检索数据？

3 个答案: