org.aectann.postage.TrackingStatusRefreshTask.java Source code

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Here is the source code for org.aectann.postage.TrackingStatusRefreshTask.java

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/*
 * Copyright 2011 Konstantin Burov (aectann@gmail.com)
 * 
 * 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 org.aectann.postage;

import java.io.InputStream;
import java.text.SimpleDateFormat;

import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;
import javax.xml.parsers.FactoryConfigurationError;

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.w3c.dom.Document;
import org.w3c.dom.NamedNodeMap;
import org.w3c.dom.Node;
import org.w3c.dom.NodeList;

import android.content.Context;
import android.os.AsyncTask;

public class TrackingStatusRefreshTask extends AsyncTask<String, TrackingInfo, String> {

    private final Context context;

    /**
     * @param context
     */
    TrackingStatusRefreshTask(Context context) {
        this.context = context;
    }

    @Override
    protected String doInBackground(String... trackingNumbers) {
        for (String trackingNumber : trackingNumbers) {
            try {
                TrackingInfo trackingInfo = syncRequest(context, trackingNumber);
                if (trackingInfo != null) {
                    publishProgress(trackingInfo);
                } else {
                    return context.getString(R.string.error_loading_postage_data);
                }
            } catch (Exception e) {
                return context.getString(R.string.error_loading_postage_data);
            }
        }
        return null;
    }

    public static TrackingInfo syncRequest(Context context, String tracking) throws FactoryConfigurationError {
        TrackingInfo result = null;
        if (tracking != null && tracking.length() > 0) {
            tracking = tracking.toUpperCase();
            HttpClient client = new DefaultHttpClient();
            try {
                HttpResponse response = client.execute(new HttpGet("http://prishlo.li/" + tracking + ".xml"));
                if (response.getStatusLine().getStatusCode() == HttpStatus.SC_OK) {
                    InputStream content = response.getEntity().getContent();
                    DocumentBuilderFactory documentBuilderFactory = DocumentBuilderFactory.newInstance();
                    DocumentBuilder documentBuilder = documentBuilderFactory.newDocumentBuilder();
                    Document document = documentBuilder.parse(content);
                    String weight = getFirstVaueOrNull(document, "weight");
                    String from = getFirstVaueOrNull(document, "from");
                    String kind = getFirstVaueOrNull(document, "kind");
                    TrackingInfo old = TrackingStorageUtils.loadStoredTrackingInfo(tracking, context);
                    result = new TrackingInfo(old != null ? old.getName() : null, tracking, weight, kind, from);
                    NodeList checkpoints = document.getElementsByTagName("checkpoint");

                    SimpleDateFormat dateFormat = new SimpleDateFormat("yyyy-MM-dd'T'HH:mm:ss");
                    for (int i = 0; i < checkpoints.getLength(); i++) {
                        Node current = checkpoints.item(i);
                        NamedNodeMap attributes = current.getAttributes();
                        Node state = attributes.getNamedItem("state");
                        Node attribute = attributes.getNamedItem("attribute");
                        Node date = attributes.getNamedItem("date");

                        String dateString = date.getNodeValue();
                        String attributeString = attribute.getNodeValue();
                        String stateString = state.getNodeValue();
                        String locationString = current.getFirstChild().getNodeValue();
                        result.addStatus(new TrackingStatus(stateString, dateFormat.parse(dateString),
                                attributeString, locationString));
                    }
                }
            } catch (Exception e) {
                if (result == null) {
                    result = new TrackingInfo(null, tracking, null, null, null);
                }
            }
        }
        return result;
    }

    private static String getFirstVaueOrNull(Document document, String tag) {
        NodeList elements = document.getElementsByTagName(tag);
        String result = null;
        if (elements.getLength() > 0) {
            Node firstChild = elements.item(0).getFirstChild();
            String nodeValue;
            if (firstChild != null && (nodeValue = firstChild.getNodeValue()) != null && nodeValue.length() > 0) {
                result = nodeValue;
            }
        }
        return result;
    }
}