com.concentricsky.android.khanacademy.data.remote.KAEntityCollectionFetcherTask.java Source code

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Here is the source code for com.concentricsky.android.khanacademy.data.remote.KAEntityCollectionFetcherTask.java

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/*
Viewer for Khan Academy
Copyright (C) 2012 Concentric Sky, Inc.
    
This program is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.
    
This program 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 General Public License for more details.
    
You should have received a copy of the GNU General Public License
along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */
package com.concentricsky.android.khanacademy.data.remote;

import java.io.IOException;
import java.util.ArrayList;
import java.util.List;

import oauth.signpost.OAuthConsumer;

import org.springframework.http.ResponseEntity;
import org.springframework.http.converter.StringHttpMessageConverter;
import org.springframework.web.client.RestTemplate;

import android.os.AsyncTask;

import com.concentricsky.android.khanacademy.data.db.ModelBase;
import com.fasterxml.jackson.core.JsonParseException;
import com.fasterxml.jackson.databind.JsonMappingException;
import com.fasterxml.jackson.databind.ObjectMapper;
import com.fasterxml.jackson.databind.type.CollectionType;
import com.fasterxml.jackson.databind.type.TypeFactory;

public abstract class KAEntityCollectionFetcherTask<T extends ModelBase> extends AsyncTask<Void, Integer, List<T>> {

    //   private TypeReference<List<T>> type;
    //   private JavaType type;
    private CollectionType type;
    private String url;
    private OAuthConsumer consumer;

    protected Exception exception;

    public KAEntityCollectionFetcherTask(Class<T> type, String url) {
        this.url = url;
        TypeFactory f = TypeFactory.defaultInstance();
        //      this.type = new TypeReference<List<T>>() {};
        //      this.type = f.constructParametricType(ArrayList.class, type);
        this.type = f.constructCollectionType(ArrayList.class, type);
    }

    public KAEntityCollectionFetcherTask(Class<T> type, String url, OAuthConsumer consumer) {
        this(type, url);
        this.consumer = consumer;
    }

    @Override
    protected List<T> doInBackground(Void... arg0) {
        // call  API and fetch an entity tree (commonly the tree rooted at the root topic)

        RestTemplate restTemplate = new RestTemplate();
        if (consumer != null) {
            restTemplate.setRequestFactory(new SpringRequestFactory(consumer));
        }

        restTemplate.getMessageConverters().add(new StringHttpMessageConverter());
        ResponseEntity<String> result = restTemplate.getForEntity(url, String.class);
        String body = result.getBody();

        // String tag = "~~~~~~~~~~~~~~~~";
        // Log.setLevel(tag, Log.VERBOSE);
        // Log.d(tag, "result body is a " + body.getClass().getCanonicalName());
        // Log.d(tag, "result is " + body);

        ObjectMapper mapper = new ObjectMapper();

        List<T> list = null;
        try {
            list = mapper.readValue(body, type);
        } catch (JsonParseException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        } catch (JsonMappingException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        } catch (IOException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }

        return list;
    }

    /**
     * Called with the result of the api call. Subclasses should override this 
     * method to handle the result. If result is null, it means the api call
     * returned an unexpected object type, and the exception is available on 
     * this.exception.
     * 
     * @param result The return of the api call.
     */
    @Override
    protected abstract void onPostExecute(List<T> result);

}