Android Open Source - JsonAsyncTuto Json Async Ui Updater

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License

The source code is released under:

MIT License

Java Source Code

package json.tushar.tutorial;
/*from w  ww  . j a  v  a2  s. com*/
import java.io.IOException;
import java.util.ArrayList;
import java.util.HashMap;

import org.apache.http.client.ClientProtocolException;
import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;

import android.app.Activity;
import android.os.AsyncTask;
import android.widget.ListAdapter;
import android.widget.ListView;
import android.widget.SimpleAdapter;
import android.widget.TextView;

public class JsonAsyncUiUpdater extends AsyncTask<String, Void, JSONObject> {
  private Activity mContext;
  private TextView display;
  private ListView lView;

  public JsonAsyncUiUpdater(Activity mContext) {
    // without getting Activity context we can not use
    // findViewById inside AsyncTask
    this.mContext = mContext;
    display = (TextView) mContext.findViewById(R.id.display);
    lView = (ListView) mContext.findViewById(R.id.listView);
  }

  @Override
  protected JSONObject doInBackground(String... urlStrs) {
    // doing stuffs on background after completing, automatically
    // onPostExecute method is called
    JSONObject jsonObjResult = null;
    try {
      jsonObjResult = JSONParser.getJSONObject(urlStrs[0]);
    } catch (ClientProtocolException e) {
      e.printStackTrace();
    } catch (IOException e) {
      e.printStackTrace();
    } catch (JSONException e) {
      e.printStackTrace();
    }
    return jsonObjResult;
  }
  @Override
  protected void onPostExecute(JSONObject result) {
    // this method is called after doInBackground()
    // method completed successfully
    String jsonArrayName = "data";
    String jsonAttribName = "name";
    String jsonAttribId = "id";

    String nameStr = null;
    String idStr = null;

    JSONArray jsonArr = null;

    try {
      // getting json array out of JSONObject result
      jsonArr = result.getJSONArray(jsonArrayName);
    } catch (JSONException e) {
      e.printStackTrace();
    }

    // creating array list hash map for storing json parsed data/values
    ArrayList<HashMap<String, String>> arrList = new ArrayList<HashMap<String, String>>();

    for (int index = 0; index < jsonArr.length(); index++) {
      try {
        // getting json object from array index
        JSONObject tempJsonObj = jsonArr.getJSONObject(index);

        // getting value of attribute using key/attribute names
        nameStr = tempJsonObj.getString(jsonAttribName);
        idStr = tempJsonObj.getString(jsonAttribId);

        // creating a HashMap<Key,Value>
        HashMap<String, String> hashMap = new HashMap<String, String>();
        // storing data in key value pair into hash map
        // using hashmap.put(key,value)
        hashMap.put(jsonAttribName, nameStr);
        hashMap.put(jsonAttribId, idStr);

        // adding hash map to the array list
        arrList.add(hashMap);

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

    // Updating task for Application UI starts here

    // Creating list adapter for list view using our hashmap array list
    ListAdapter entriesAdapter = new SimpleAdapter(mContext, arrList,
        android.R.layout.two_line_list_item, new String[] {
            jsonAttribName, jsonAttribId }, new int[] {
            android.R.id.text1, android.R.id.text2 });
    // SimpleAdapter parameters: Context, List<? extends Map<String,?>>,
    // int android.R resource type,String[] from hash map key names,
    // int[] to android.R resource type where to put

    lView.setAdapter(entriesAdapter);

    display.setText("Updated!");
  }

}

Java Source Code List

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