Question

我的listblogs = parseJSONResponse（结果）出现问题，结果带有红色下划线，如果我将鼠标悬停在它上面，则表示我无法将parseJsonResponse JSONARRAY应用于JSONARRAY []。有谁知道为什么这会引起与params有关？

class YourTask extends AsyncTask<JSONArray, String, ArrayList<Blogs> > {

    @Override
    protected ArrayList<Blogs> doInBackground(JSONArray... result) {
        listblogs.clear(); // here you clear the old data
        listblogs=parseJSONResponse(result);
        return listblogs;
    }

    @Override
    protected void onPostExecute(ArrayList<Blogs> blogs) {
        mAdapterDashBoard.setBloglist(listblogs);
    }
}



private void JsonRequestMethod() {
    final long start = SystemClock.elapsedRealtime();
            mVolleySingleton = VolleySingleton.getInstance();
            //intitalize Volley Singleton request key
            mRequestQueue = mVolleySingleton.getRequestQueue();
            //2 types of requests an Array request and an Object Request
            JsonArrayRequest request = new JsonArrayRequest(Request.Method.GET, URL_API, (String) null, new Response.Listener<JSONArray>() {
                @Override
                public void onResponse(JSONArray response) {
                    System.out.print(response);
                    listblogs = new YourTask().doInBackground();
                    listblogs.clear();
                             listblogs=parseJSONResponse(response);
                    try {
                        listblogs = new YourTask().execute().get();
                    } catch (InterruptedException e) {
                        e.printStackTrace();
                    } catch (ExecutionException e) {
                        e.printStackTrace();
                    }

                    System.out.println(response);
                            Log.d("Testing", "Time elapsed: " + (SystemClock.elapsedRealtime() - start));
                    System.out.println("it worked!!!");
                }
            }, new Response.ErrorListener() {
                @Override
                public void onErrorResponse(VolleyError error) {
                }
            });
            mRequestQueue.add(request);
    }



private ArrayList<Blogs> parseJSONResponse(JSONArray response) {
    if (!response.equals("")) {
        try {
            StringBuilder data = new StringBuilder();
            for (int i = 0; i < response.length(); i++) {
                JSONObject currentQuestions = response.getJSONObject(i);
                String text = currentQuestions.getString("text");
                String points = currentQuestions.getString("points");
                String ID=currentQuestions.getString("id");
                String studentId = currentQuestions.getString("studentId");
                String DateCreated=currentQuestions.getString("created");
                long time=Long.parseLong(DateCreated.trim());
                data.append(text + "\n" + points + "\n");
                System.out.println(data);
                Blogs blogs = new Blogs();
                blogs.setId(ID);
                blogs.setMstudentId(studentId);
                blogs.setMtext(text);
                blogs.setPoints(points);
                //The dateCreated was off by 1 hour so 3600000 ms where added=1hour, (UPDATE)
                blogs.setDateCreated(getTimeAgo(time));
                System.out.println(time + "time");


                listblogs.add(blogs);


            }

        } catch (JSONException e) {
            e.printStackTrace();
        }
    }

    return listblogs;
}

Answer 1

您可以在异步任务中运行任何代码，如下所示：

public class YourTask extends AsyncTask<String, Void, ArrayList<Blogs> > {

    private static final String TAG = YourTask.class.getSimpleName();

    private JSONArray mResponse;
    private Activity mActivity;

    public YourTask(final Activity activity, final JSONArray response) {
        super();
        this.mActivity = activity;
        this.mResponse = response;
    }

    @Override
    protected ArrayList<Blogs>  doInBackground(String... params) {

        if (!mResponse.equals("")) {
               // Your Code
        }   
        return listblogs;

    }

    @Override
    protected void onPostExecute(final ArrayList<Blogs> blogs) {

            if (mActivity instanceOf YourActivity) {
                ((YourActivity) activity).finishTask(blogs);
            }
    }

    @Override
    protected void onCancelled() {}
}

从您的活动中调用此任务，例如：

AsyncTask<String, Void, JSONArray> task = new YourTask(this, response);
        task.executeContent();

基本上只需将要解析的JSONArray发送到异步任务，并在Activity中处理den finishTask方法中的所有UI。优点是您可以在额外的文件中提取任务，并让您的活动只处理控制您的视图。

Answer 2

<强>的AsyncTask

public class MyAsyncTask extends AsyncTask<Void, Void, ArrayList> {
         JsonArray myJsonArray;
   @Override
    protected void onPreExecute() {
        super.onPreExecute();

            mVolleySingleton = VolleySingleton.getInstance();

            mRequestQueue = mVolleySingleton.getRequestQueue();

            listblogs.clear();

        }
        @Override
        protected ArrayList doInBackground(Void... params) {


            JsonArrayRequest request = new JsonArrayRequest(Request.Method.GET, URL_API, (String) null, new Response.Listener<JSONArray>() {
                @Override
                public void onResponse(JSONArray response) {

                    myJsonArray = response;

                }
            }, new Response.ErrorListener() {
                @Override
                public void onErrorResponse(VolleyError error) {
                }
            });
            mRequestQueue.add(request);
            return null;
        }

        @Override
        protected void onPostExecute(ArrayList arrayList) {
            super.onPostExecute(arrayList);

              ArrayList<Blogs> blogsArrayList = new ArrayList<>();
    try {
        StringBuilder data = new StringBuilder();
        for (int i = 0; i < myJsonArray.length(); i++) {
            JSONObject currentQuestions = myJsonArray.getJSONObject(i);
            String text = currentQuestions.getString("text");
            String points = currentQuestions.getString("points");
            String ID=currentQuestions.getString("id");
            String studentId = currentQuestions.getString("studentId");
            String DateCreated=currentQuestions.getString("created");
            long time=Long.parseLong(DateCreated.trim());
            data.append(text + "\n" + points + "\n");
            System.out.println(data);
            Blogs blogs = new Blogs();
            blogs.setId(ID);
            blogs.setMstudentId(studentId);
            blogs.setMtext(text);
            blogs.setPoints(points);
            //The dateCreated was off by 1 hour so 3600000 ms where added=1hour, (UPDATE)
            blogs.setDateCreated(getTimeAgo(time));
            System.out.println(time+"time");


            blogsArrayList.add(blogs);
            }
    } catch (JSONException e) {
        e.printStackTrace();
    }
    return blogsArrayList;

    }

<强>的ArrayList

同步：

  listblogs = new MyAsyncTask().execute().get();

异步：

   ....
      } catch (JSONException e) {
            e.printStackTrace();
        }
        listblogs = blogsArrayList;
        return blogsArrayList;

        }
new MyAsyncTask().execute();

如何为此代码设置异步任务？

2 个答案: