org.ounl.lifelonglearninghub.learntracker.gis.ou.db.ws.SubjectWSGetAsyncTask.java Source code

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Here is the source code for org.ounl.lifelonglearninghub.learntracker.gis.ou.db.ws.SubjectWSGetAsyncTask.java

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/*******************************************************************************
 * Copyright (C) 2014 Open University of The Netherlands
 * Author: Bernardo Tabuenca Archilla
 * LearnTracker project 
 * 
 * This library is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Lesser General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 * 
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU Lesser General Public License for more details.
 * 
 * You should have received a copy of the GNU Lesser General Public License
 * along with this library.  If not, see <http://www.gnu.org/licenses/>.
 ******************************************************************************/
package org.ounl.lifelonglearninghub.learntracker.gis.ou.db.ws;

import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.Reader;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;

import org.apache.http.HttpEntity;
import org.apache.http.HttpResponse;
import org.apache.http.HttpStatus;
import org.apache.http.client.HttpClient;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.impl.client.DefaultHttpClient;
import org.ounl.lifelonglearninghub.learntracker.gis.ou.db.ws.dataobjects.SubjectDO;
import org.ounl.lifelonglearninghub.learntracker.gis.ou.db.ws.dataobjects.SubjectDOList;
import org.ounl.lifelonglearninghub.learntracker.gis.ou.session.Session;

import android.os.AsyncTask;
import android.util.Log;

import com.google.gson.Gson;

public class SubjectWSGetAsyncTask extends AsyncTask<String, Integer, List<SubjectDO>> {

    private String CLASSNAME = this.getClass().getName();

    public List<SubjectDO> listSubjects(String sCourseId) {

        // e.g. query https://lifelong-learning-hub.appspot.com/_ah/api/subjectendpoint/v1/subject/course/S23222

        InputStream is = null;
        String url = Session.getSingleInstance().getWSPath() + "/_ah/api/subjectendpoint/v1/subject/course/";
        url += sCourseId;

        try {
            Log.d(CLASSNAME, " Querying to backend " + url);
            HttpClient httpclient = new DefaultHttpClient();
            HttpGet httpget = new HttpGet(url);
            HttpResponse response = httpclient.execute(httpget);

            final int statusCode = response.getStatusLine().getStatusCode();
            if (statusCode != HttpStatus.SC_OK) {
                Log.w(getClass().getSimpleName(), "Error " + statusCode + " for URL " + url);
                return null;
            }

            HttpEntity entity = response.getEntity();
            is = entity.getContent();

        } catch (Exception e) {
            Log.e(CLASSNAME, "Error in http connection " + e.toString());
        }

        Reader reader = new InputStreamReader(is);
        Gson gson = new Gson();
        SubjectDOList r = gson.fromJson(reader, SubjectDOList.class);
        List<SubjectDO> subjects = r.subjects;

        return subjects;
    }

    @Override
    protected void onPreExecute() {
        super.onPreExecute();

    }

    @Override
    protected List<SubjectDO> doInBackground(String... sParam) {

        Log.d(CLASSNAME, "Starting " + CLASSNAME + " task in background...");

        List<SubjectDO> sOutList = new ArrayList<SubjectDO>();

        try {

            Log.d(CLASSNAME, "Course ID [" + sParam[0].toString() + "]");

            sOutList = listSubjects(sParam[0].toString());
            Log.d(CLASSNAME, toString(sOutList));

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

        return sOutList;
    }

    @Override
    protected void onPostExecute(List<SubjectDO> result) {
        super.onPostExecute(result);

    }

    /**
     * Returns list of subjects ordered by task_order
     * @return
     */
    public List<SubjectDO> orderedSubjects(List<SubjectDO> subjects) {

        SubjectDO[] ordered = new SubjectDO[subjects.size()];

        int i = 0;
        for (SubjectDO subjectDO : subjects) {
            Integer oI = new Integer(subjectDO.getSubject_task_order());
            ordered[oI.intValue()] = subjectDO;
            i++;
        }

        return Arrays.asList(ordered);
    }

    /**
     * Print items in debug mode
     * @param list
     */
    public String toString(List<SubjectDO> list) {

        String sResult = "";
        for (SubjectDO subjectDO : list) {
            sResult += subjectDO.toString();
        }

        return sResult;

    }

}