Java tutorial
/* * FlightIntel for Pilots * * Copyright 2012-2015 Nadeem Hasan <nhasan@nadmm.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 com.nadmm.airports.library; import android.app.IntentService; import android.content.Intent; import android.os.Bundle; import android.os.ResultReceiver; import android.support.v4.content.LocalBroadcastManager; import com.nadmm.airports.utils.NetworkUtils; import com.nadmm.airports.utils.SystemUtils; import com.nadmm.airports.utils.UiUtils; import java.io.File; import java.net.URL; import java.util.ArrayList; public class LibraryService extends IntentService { private static final String SERVICE_NAME = "library"; public static final String LIBRARY_HOST = "commondatastorage.googleapis.com"; public static final String LIBRARY_PATH = "/flightintel/library"; public static final String ACTION_GET_BOOK = "flightintel.library.action.GET_BOOK"; public static final String ACTION_DELETE_BOOK = "flightintel.library.action.DELETE_BOOK"; public static final String ACTION_CHECK_BOOKS = "flightintel.library.action.CHECK_BOOKS"; public static final String ACTION_DOWNLOAD_PROGRESS = "flightintel.library.action.PROGRESS"; public static final String CATEGORY = "CATEGORY"; public static final String BOOK_NAME = "BOOK_NAME"; public static final String BOOK_NAMES = "BOOK_NAMES"; public static final String PDF_PATH = "PDF_PATH"; private File mDataDir; public LibraryService() { super(SERVICE_NAME); } @Override public void onCreate() { super.onCreate(); mDataDir = SystemUtils.getExternalDir(this, SERVICE_NAME); } @Override protected void onHandleIntent(Intent intent) { String action = intent.getAction(); if (action.equals(ACTION_CHECK_BOOKS)) { checkBooks(intent); } else if (action.equals(ACTION_GET_BOOK)) { getBook(intent); } else if (action.equals(ACTION_DELETE_BOOK)) { deleteBook(intent); } } private void checkBooks(Intent intent) { String category = intent.getStringExtra(CATEGORY); ArrayList<String> books = intent.getStringArrayListExtra(BOOK_NAMES); cleanupBooks(category, books); File categoryDir = getCategoryDir(category); for (String book : books) { File pdfFile = new File(categoryDir, book); sendResult(intent.getAction(), category, pdfFile); } } private void getBook(Intent intent) { String category = intent.getStringExtra(CATEGORY); String book = intent.getStringExtra(BOOK_NAME); File categoryDir = getCategoryDir(category); File pdfFile = new File(categoryDir, book); if (!pdfFile.exists()) { fetch(category, pdfFile); } sendResult(intent.getAction(), category, pdfFile); } private void deleteBook(Intent intent) { String category = intent.getStringExtra(CATEGORY); String book = intent.getStringExtra(BOOK_NAME); File categoryDir = getCategoryDir(category); File pdfFile = new File(categoryDir, book); if (pdfFile.exists()) { pdfFile.delete(); } sendResult(ACTION_CHECK_BOOKS, category, pdfFile); } private boolean fetch(String category, File pdfFile) { try { ProgressReceiver receiver = new ProgressReceiver(); Bundle result = new Bundle(); result.putString(NetworkUtils.CONTENT_NAME, pdfFile.getName()); result.putString(CATEGORY, category); String path = LIBRARY_PATH + "/" + category + "/" + pdfFile.getName() + ".gz"; URL url = new URL("http", LIBRARY_HOST, path); return NetworkUtils.doHttpGetGzip(this, url, pdfFile, receiver, result); } catch (Exception e) { UiUtils.showToast(this, e.getMessage()); } return false; } protected void sendResult(String action, String category, File pdfFile) { Intent result = new Intent(action); result.putExtra(CATEGORY, category); result.putExtra(BOOK_NAME, pdfFile.getName()); if (pdfFile.exists()) { result.putExtra(PDF_PATH, pdfFile.getAbsolutePath()); } LocalBroadcastManager bm = LocalBroadcastManager.getInstance(this); bm.sendBroadcast(result); } private void cleanupBooks(String category, ArrayList<String> books) { // Delete all books that are no longer in the library list for a category File categoryDir = getCategoryDir(category); File[] list = categoryDir.listFiles(); if (list != null) { for (File pdfFile : list) { if (!books.contains(pdfFile.getName())) { pdfFile.delete(); } } } } private File getCategoryDir(String category) { File categoryDir = new File(mDataDir, category); if (!categoryDir.exists()) { categoryDir.mkdirs(); } return categoryDir; } protected void handleProgress(int resultCode, Bundle resultData) { Intent intent = new Intent(ACTION_DOWNLOAD_PROGRESS); intent.putExtras(resultData); LocalBroadcastManager bm = LocalBroadcastManager.getInstance(this); bm.sendBroadcast(intent); } private class ProgressReceiver extends ResultReceiver { public ProgressReceiver() { super(null); } @Override public void send(int resultCode, Bundle resultData) { // We want to handle the result in the same thread synchronously handleProgress(resultCode, resultData); } } }