edu.upf.nets.mercury.geoip.GeoIpDatabase.java Source code

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Here is the source code for edu.upf.nets.mercury.geoip.GeoIpDatabase.java

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/* 
 * Copyright (C) 2013 Alex Bikfalvi
 *
 * 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, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
 */

package edu.upf.nets.mercury.geoip;

import java.io.ByteArrayInputStream;
import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.net.MalformedURLException;
import java.net.URL;
import java.util.zip.GZIPInputStream;

import org.apache.commons.io.IOUtils;

import com.maxmind.geoip.LookupService;

import edu.upf.nets.mercury.geoip.net.AsyncWebRequest;
import edu.upf.nets.mercury.geoip.net.AsyncWebState;
import edu.upf.nets.mercury.geoip.net.IAsyncCallback;
import edu.upf.nets.mercury.geoip.net.IAsyncResult;

/**
 * A class representing a specific GeoIP database
 * @author Alex
 *
 */
public class GeoIpDatabase implements IAsyncCallback {

    private String name = null;
    private LookupService service = null;

    private AsyncWebRequest request = new AsyncWebRequest();

    /**
     * Creates a new GeoIP database instance.
     * @param The collection name used by this database.
     */
    public GeoIpDatabase(String name) {
        this.name = name;
    }

    public final LookupService getService() {
        return this.service;
    }

    public void load() {

    }

    public void save() {

    }

    public void close() {
        this.request.close();
    }

    /**
     * Updates the current database using data from the specified URL. The download is performed
     * asynchronously. 
     * @param urlString The url from where to download the GeoIP database.
     * @param callback The callback object.
     * @return The result of the asyncrhonous operation.
     * @throws MalformedURLException
     */
    public IAsyncResult update(String urlString, IAsyncCallback callback) throws MalformedURLException {
        // Create the URL for this request.
        URL url = new URL(urlString);
        // Execute the asynchronous request for the specified URL, using the user callback object as user state.
        return this.request.execute(url, this, callback);
    }

    /**
     * An event handler called when the asynchronous web request has completed execution.
     * @param The asynchronous result.
     */
    public void callback(IAsyncResult result) {
        // Get the state of the asynchronous request.
        AsyncWebState state = (AsyncWebState) result;
        try {
            // Try and process the data.
            this.process(state.getResponse());
        } catch (Exception e) {
            // Catch all exceptions.
        } finally {
            // Get the user callback function.
            IAsyncCallback callback = (IAsyncCallback) state.getState();
            // If the callback is not null.
            if (null != callback) {
                // Call the user callback method.
                callback.callback(result);
            }
        }
    }

    /**
     * Processes the GZIP data and loads it into the current database.
     * @param data The GeoIP data.
     */
    private void process(byte[] data) throws GeoIpException {
        // Create an input stream from the byte array data.
        InputStream inputStream = new ByteArrayInputStream(data);

        try {
            // Create a GZIP input stream.
            GZIPInputStream zipStream = new GZIPInputStream(inputStream);
            // Create a temporary file for this database.
            File file = File.createTempFile(this.name, ".tmp");
            file.deleteOnExit();
            // Copy the data from.
            IOUtils.copy(zipStream, new FileOutputStream(file));
            // Location service.
            this.service = new LookupService(file);
        } catch (IOException exception) {
            throw new GeoIpException("Could not UNZIP the received data file.", exception);
        }
    }
}