Question

I make some JSON parser, and i wanna to show information in same ListView. I try to use AsynkTask but it didn’t work.

For ListView i create simple class Plase and Adapter which extends from ArrayAdapter.

There is my code:

import android.app.Activity;
import android.app.ProgressDialog;
import android.os.AsyncTask;
import android.os.Bundle;
import android.widget.ArrayAdapter;
import android.widget.ListView;
import org.json.simple.JSONArray;
import org.json.simple.JSONObject;
import org.json.simple.parser.JSONParser;
import org.json.simple.parser.ParseException;

import java.io.*;
import java.net.URL;
import java.net.URLConnection;
import java.util.ArrayList;

public class ListActivity extends Activity {
    private static final String API_START = "http://api.yelp.com/business_review_search?location=";
    private static final String API_END = "&ywsid=mlNrKepTs01H6gB0yoIWrw";
    private String mRequestURL = "http://api.yelp.com/business_review_search?location=New%20York&ywsid=mlNrKepTs01H6gB0yoIWrw";
    public static ArrayAdapter<Place> mAdapter = null;
    private ListView mListView;
    ArrayList<Place> arrayList = new ArrayList<Place>();
    ProgressDialog dialog;




    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.list);


       if (mRequestURL == null) {
           mRequestURL ="http://api.yelp.com/business_review_search?location=New%20York&ywsid=mlNrKepTs01H6gB0yoIWrw";
       }

       if (mAdapter==null && mRequestURL!=null) {
           new DownloadFilesTask().execute(mRequestURL, null, null);
           mAdapter = new Adapter(ListActivity.this, arrayList);
       }

        mListView = (ListView) findViewById(R.id.list);
        mListView.setAdapter(mAdapter);

    }

    private class DownloadFilesTask extends AsyncTask<String, Void, Void> {

        @Override
        protected void onPreExecute() {
            dialog = new ProgressDialog(ListActivity.this);
            dialog.setMessage("Please wait");
            dialog.setIndeterminate(true);
            dialog.setCancelable(true);
            dialog.show();

        }

        protected Void doInBackground(String... urls) {
            try {
                arrayList = parse(mRequestURL);
            } catch (IOException e) {
                e.printStackTrace();  //To change body of catch statement use File | Settings | File Templates.
            } catch (ParseException e) {
                e.printStackTrace();  //To change body of catch statement use File | Settings | File Templates.
            }
            return(null);
        }

      @Override
        protected void onPostExecute(Void places) {
            dialog.dismiss();
        }
    }

    private ArrayList<Place> parse(String u) throws IOException, ParseException {

        URL url = new URL(u);
        StringBuilder sb = new StringBuilder();
        URLConnection yc = url.openConnection();
        BufferedReader in = new BufferedReader(new InputStreamReader(yc.getInputStream()));
        String s;
        while ((s=in.readLine()) != null)
            sb.append(s);
        in.close();

        JSONParser parser = new JSONParser();
            Object o = parser.parse(sb.toString());
            JSONObject jsonObject1 = (JSONObject) o;
            JSONArray jsonArray = (JSONArray) jsonObject1.get("businesses");
            for(int i=0; i<jsonArray.size(); i++) {
                JSONObject obj = (JSONObject) jsonArray.get(i);
                URL photo_url = new URL((String) obj.get("photo_url"));
                URL place_url = new URL((String) obj.get("url"));
                String name = (String) obj.get("name");
                String address = obj.get("city") + " " + obj.get("address1");
                long latitude = Long.parseLong((String) obj.get("latitude"));
                long longitude = Long.parseLong((String) obj.get("longitude"));
                arrayList.add(new Place(photo_url, name, address, place_url, latitude, longitude));
            }

        File file = new File("File.txt");
        ObjectOutputStream oout = new ObjectOutputStream(openFileOutput("File.txt" , 0));
        oout.writeObject(arrayList);
        oout.close();
        return arrayList;

    }


}

My app die with that erros:

07-26 14:23:04.246: ERROR/AndroidRuntime(9262): FATAL EXCEPTION: AsyncTask #1
        java.lang.RuntimeException: An error occured while executing doInBackground()
        at android.os.AsyncTask$3.done(AsyncTask.java:200)
        at java.util.concurrent.FutureTask$Sync.innerSetException(FutureTask.java:273)
        at java.util.concurrent.FutureTask.setException(FutureTask.java:124)
        at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:307)
        at java.util.concurrent.FutureTask.run(FutureTask.java:137)
        at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1068)
        at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:561)
        at java.lang.Thread.run(Thread.java:1096)
        Caused by: java.lang.ClassCastException: java.lang.Double
        at com.example.ListActivity.parse(ListActivity.java:105)
        at com.example.ListActivity.access$200(ListActivity.java:20)
        at com.example.ListActivity$DownloadFilesTask.doInBackground(ListActivity.java:69)
        at com.example.ListActivity$DownloadFilesTask.doInBackground(ListActivity.java:55)
        at android.os.AsyncTask$2.call(AsyncTask.java:185)
        at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:305)
        ... 4 more
07-26 14:23:04.658: ERROR/WindowManager(9262): Activity com.example.ListActivity has leaked window com.android.internal.policy.impl.PhoneWindow$DecorView@44f1be88 that was originally added here
        android.view.WindowLeaked: Activity com.example.ListActivity has leaked window com.android.internal.policy.impl.PhoneWindow$DecorView@44f1be88 that was originally added here
        at android.view.ViewRoot.<init>(ViewRoot.java:247)
        at android.view.WindowManagerImpl.addView(WindowManagerImpl.java:148)
        at android.view.WindowManagerImpl.addView(WindowManagerImpl.java:91)
        at android.view.Window$LocalWindowManager.addView(Window.java:424)
        at android.app.Dialog.show(Dialog.java:241)
        at com.example.ListActivity$DownloadFilesTask.onPreExecute(ListActivity.java:63)
        at android.os.AsyncTask.execute(AsyncTask.java:391)
        at com.example.ListActivity.onCreate(ListActivity.java:46)
        at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1047)
        at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2627)
        at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2679)
        at android.app.ActivityThread.access$2300(ActivityThread.java:125)
        at android.app.ActivityThread$H.handleMessage(ActivityThread.java:2033)
        at android.os.Handler.dispatchMessage(Handler.java:99)
        at android.os.Looper.loop(Looper.java:123)
        at android.app.ActivityThread.main(ActivityThread.java:4627)
        at java.lang.reflect.Method.invokeNative(Native Method)
        at java.lang.reflect.Method.invoke(Method.java:521)
        at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:868)
        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:626)
        at dalvik.system.NativeStart.main(Native Method)

Answer 1

Check latitude and longitude ,may be its double not long

 double latitude = obj.getDouble("latitude");
 double longitude = obj.getDouble("longitude");

AND set Adapter to listview in onPostExecute() method...

    @Override
    protected void onPostExecute(Void places) {
        dialog.dismiss();

    mAdapter = new Adapter(ListActivity.this, arrayList);
    mListView = (ListView) findViewById(R.id.list);
    mListView.setAdapter(mAdapter);
    }