Java tutorial
package com.bellman.bible.service.common; import android.content.SharedPreferences; import android.content.pm.PackageInfo; import android.content.pm.PackageManager; import android.content.pm.PackageManager.NameNotFoundException; import android.content.res.Configuration; import android.os.Build; import android.os.Environment; import android.os.StatFs; import android.preference.PreferenceManager; import android.support.v7.widget.PopupMenu; import android.util.Log; import com.bellman.bible.android.control.ControlFactory; import com.bellman.bible.android.control.page.window.Window; import com.bellman.bible.android.view.activity.base.CurrentActivityHolder; import org.apache.commons.lang3.StringUtils; import org.apache.commons.lang3.time.DateUtils; import org.crosswire.common.util.IOUtil; import org.crosswire.jsword.passage.Key; import org.crosswire.jsword.passage.Verse; import org.crosswire.jsword.passage.VerseRange; import org.crosswire.jsword.versification.BibleBook; import org.crosswire.jsword.versification.Versification; import java.io.File; import java.io.FileInputStream; import java.io.IOException; import java.lang.reflect.Field; import java.lang.reflect.Method; import java.net.HttpURLConnection; import java.net.URL; import java.util.Calendar; import java.util.Date; import java.util.Properties; /** * @author Martin Denham [mjdenham at gmail dot com] * @see gnu.lgpl.License for license details.<br> * The copyright to this program is held by it's author. */ public class CommonUtils { private static final String COLON = ":"; private static final int DEFAULT_MAX_TEXT_LENGTH = 250; private static final String ELLIPSIS = "..."; private static final String TAG = "CommonUtils"; static private boolean isAndroid = false; //todo have to finish implementing switchable logging here static { try { if (Build.ID != null) { isAndroid = true; } } catch (Exception cnfe) { isAndroid = false; } System.out.println("isAndroid:" + isAndroid); } public static boolean isAndroid() { return isAndroid; } public static String getApplicationVersionName() { String versionName = null; try { PackageManager manager = CurrentActivityHolder.getInstance().getApplication().getPackageManager(); PackageInfo info = manager .getPackageInfo(CurrentActivityHolder.getInstance().getApplication().getPackageName(), 0); versionName = info.versionName; } catch (final NameNotFoundException e) { Log.e(TAG, "Error getting package name.", e); versionName = "Error"; } return versionName; } public static int getApplicationVersionNumber() { int versionNumber; try { PackageManager manager = CurrentActivityHolder.getInstance().getApplication().getPackageManager(); PackageInfo info = manager .getPackageInfo(CurrentActivityHolder.getInstance().getApplication().getPackageName(), 0); versionNumber = info.versionCode; } catch (final NameNotFoundException e) { Log.e(TAG, "Error getting package name.", e); versionNumber = -1; } return versionNumber; } public static boolean isFroyoPlus() { return Build.VERSION.SDK_INT >= Build.VERSION_CODES.FROYO; } /** return true if Android 2.3.7 or greater */ public static boolean is2_3_7_Plus() { if (Build.VERSION.SDK_INT > 9) { return true; } else if (Build.VERSION.SDK_INT < 9) { return false; } else { // this isn't brilliant code but should not fail and should work most times, maybe all String rel = Build.VERSION.RELEASE; String finalDigit = StringUtils.right(rel, 1); return "789".contains(finalDigit); } } public static boolean isGingerBreadPlus() { return Build.VERSION.SDK_INT >= 9; } public static boolean isHoneycombPlus() { return Build.VERSION.SDK_INT >= 11; } public static boolean isIceCreamSandwichPlus() { return Build.VERSION.SDK_INT >= 14; } public static boolean isJellyBeanPlus() { return Build.VERSION.SDK_INT >= 16; } public static boolean isKitKatPlus() { return Build.VERSION.SDK_INT >= 19; } public static long getSDCardMegsFree() { long bytesAvailable = getFreeSpace(Environment.getExternalStorageDirectory().getPath()); long megAvailable = bytesAvailable / 1048576; Log.d(TAG, "Megs available on SD card :" + megAvailable); return megAvailable; } public static long getFreeSpace(String path) { StatFs stat = new StatFs(path); long bytesAvailable = (long) stat.getBlockSize() * (long) stat.getAvailableBlocks(); Log.d(TAG, "Free space :" + bytesAvailable); return bytesAvailable; } /** shorten text for display in lists etc. * * @param text * @return */ public static String limitTextLength(String text) { return limitTextLength(text, DEFAULT_MAX_TEXT_LENGTH); } public static String limitTextLength(String text, int maxLength) { return limitTextLength(text, maxLength, false); } public static String limitTextLength(String text, int maxLength, boolean singleLine) { if (text != null) { int origLength = text.length(); if (singleLine) { // get first line but limit length in case there are no line breaks text = StringUtils.substringBefore(text, "\n"); } if (text.length() > maxLength) { // break on a space rather than mid-word int cutPoint = text.indexOf(" ", maxLength); if (cutPoint >= maxLength) { text = text.substring(0, cutPoint + 1); } } if (text.length() != origLength) { text += ELLIPSIS; } } return text; } public static boolean isInternetAvailable() { String testUrl = "http://www.crosswire.org/ftpmirror/pub/sword/packages/rawzip/"; return CommonUtils.isHttpUrlAvailable(testUrl); } /** return true if URL is accessible * * Since Android 3 must do on different or NetworkOnMainThreadException is thrown */ public static boolean isHttpUrlAvailable(final String urlString) { boolean isAvailable = false; final int TIMEOUT_MILLIS = 3000; try { class CheckUrlThread extends Thread { public boolean checkUrlSuccess = false; public void run() { HttpURLConnection connection = null; try { // might as well test for the url we need to access URL url = new URL(urlString); Log.d(TAG, "Opening test connection"); connection = (HttpURLConnection) url.openConnection(); connection.setConnectTimeout(TIMEOUT_MILLIS); connection.setReadTimeout(TIMEOUT_MILLIS); connection.setRequestMethod("HEAD"); Log.d(TAG, "Connecting to test internet connection"); connection.connect(); checkUrlSuccess = (connection.getResponseCode() == HttpURLConnection.HTTP_OK); Log.d(TAG, "Url test result for:" + urlString + " is " + checkUrlSuccess); } catch (IOException e) { Log.i(TAG, "No internet connection"); checkUrlSuccess = false; } finally { if (connection != null) { connection.disconnect(); } } } } CheckUrlThread checkThread = new CheckUrlThread(); checkThread.start(); checkThread.join(TIMEOUT_MILLIS); isAvailable = checkThread.checkUrlSuccess; } catch (InterruptedException e) { Log.e(TAG, "Interrupted waiting for url check to complete", e); } return isAvailable; } public static void ensureDirExists(File dir) { if (!dir.exists() || !dir.isDirectory()) { dir.mkdirs(); } } public static boolean deleteDirectory(File path) { Log.d(TAG, "Deleting directory:" + path.getAbsolutePath()); if (path.exists()) { if (path.isDirectory()) { File[] files = path.listFiles(); for (int i = 0; i < files.length; i++) { if (files[i].isDirectory()) { deleteDirectory(files[i]); } else { files[i].delete(); Log.d(TAG, "Deleted " + files[i]); } } } boolean deleted = path.delete(); if (!deleted) { Log.w(TAG, "Failed to delete:" + path.getAbsolutePath()); } return deleted; } return false; } public static Properties loadProperties(File propertiesFile) { Properties properties = new Properties(); if (propertiesFile.exists()) { FileInputStream in = null; try { in = new FileInputStream(propertiesFile); properties.load(in); } catch (Exception e) { Log.e(TAG, "Error loading properties", e); } finally { IOUtil.close(in); } } return properties; } public static void pause(int seconds) { pauseMillis(seconds * 1000); } public static void pauseMillis(int millis) { try { Thread.sleep(millis); } catch (Exception e) { Log.e(TAG, "Error sleeping", e); } } public static boolean isPortrait() { return CurrentActivityHolder.getInstance().getApplication().getResources() .getConfiguration().orientation == Configuration.ORIENTATION_PORTRAIT; } public static String getLocalePref() { return getSharedPreferences().getString("locale_pref", ""); } /** get preferences used by User Prefs screen * * @return */ public static SharedPreferences getSharedPreferences() { return PreferenceManager.getDefaultSharedPreferences(CurrentActivityHolder.getInstance().getContext()); } public static String getSharedPreference(String key, String defaultValue) { return getSharedPreferences().getString(key, defaultValue); } public static void saveSharedPreference(String key, String value) { SharedPreferences prefs = CommonUtils.getSharedPreferences(); prefs.edit().putString(key, value).commit(); } public static String getResourceString(int resourceId, Object... formatArgs) { return CurrentActivityHolder.getInstance().getApplication().getResources().getString(resourceId, formatArgs); } public static int getResourceInteger(int resourceId) { return CurrentActivityHolder.getInstance().getApplication().getResources().getInteger(resourceId); } public static boolean getResourceBoolean(int resourceId) { return CurrentActivityHolder.getInstance().getApplication().getResources().getBoolean(resourceId); } public static int getResourceColor(int resourceId) { return CurrentActivityHolder.getInstance().getApplication().getResources().getColor(resourceId); } /** * convert dip measurements to pixels */ public static int convertDipsToPx(int dips) { // Converts 14 dip into its equivalent px float scale = CurrentActivityHolder.getInstance().getApplication().getResources() .getDisplayMetrics().density; return (int) (dips * scale + 0.5f); } /** * convert dip measurements to pixels */ public static int convertPxToDips(int px) { float scale = CurrentActivityHolder.getInstance().getApplication().getResources() .getDisplayMetrics().density; return Math.round(px / scale); } /** * StringUtils methods only compare with a single char and hence create lots * of temporary Strings This method compares with all chars and just creates * one new string for each original string. This is to minimise memory * overhead & gc. * * @param str * @param removeChars * @return */ public static String remove(String str, char[] removeChars) { if (StringUtils.isEmpty(str) || !StringUtils.containsAny(str, removeChars)) { return str; } StringBuilder r = new StringBuilder(str.length()); // for all chars in string for (int i = 0; i < str.length(); i++) { char strCur = str.charAt(i); // compare with all chars to be removed boolean matched = false; for (int j = 0; j < removeChars.length && !matched; j++) { if (removeChars[j] == strCur) { matched = true; } } // if current char does not match any in the list then add it to the if (!matched) { r.append(strCur); } } return r.toString(); } public static Date getTruncatedDate() { return DateUtils.truncate(new Date(), Calendar.DAY_OF_MONTH); } /** format seconds duration as h:m:s * * @param secs duration * @return h:m:s */ public static String getHoursMinsSecs(long secs) { int h = (int) (secs / 3600); int m = (int) ((secs / 60) % 60); int s = (int) (secs % 60); StringBuilder hms = new StringBuilder(); if (h > 0) { hms.append(h).append(COLON); } // add padding for 1 digit mins if (m < 10) { hms.append(0); } hms.append(m).append(COLON); // add padding for 1 digit secs if (s < 10) { hms.append(0); } hms.append(s); return hms.toString(); } public static Window getActiveWindow() { return ControlFactory.getInstance().getWindowControl().getActiveWindow(); } public static String getKeyDescription(Key key) { String name; try { name = key.getName(); // do not show verse 0 if (key instanceof Verse) { Verse verseKey = (Verse) key; if (verseKey.getVerse() == 0 && name.endsWith("0")) { final String verse0 = "[\\W]0$"; name = name.replaceAll(verse0, ""); } } } catch (Exception e) { Log.e(TAG, "Error getting key name - could that Versification does not contain book"); // but this normally works name = key.getOsisRef().replace('.', ' '); } return name; } public static Key getWholeChapter(Verse currentVerse) { Log.i(TAG, "Get Chapter for:" + currentVerse.getOsisID()); Versification versification = currentVerse.getVersification(); BibleBook book = currentVerse.getBook(); int chapter = currentVerse.getChapter(); Verse targetChapterFirstVerse = new Verse(versification, book, chapter, 0); Verse targetChapterLastVerse = new Verse(versification, book, chapter, versification.getLastVerse(book, chapter)); // convert to full chapter before returning because bible view is for a full chapter return new VerseRange(versification, targetChapterFirstVerse, targetChapterLastVerse); } /** enable performance adjustments for slow devices */ public static boolean isSlowDevice() { return Runtime.getRuntime().availableProcessors() == 1; } /** * By default popup menus do not show icons, but see the trick below * http://stackoverflow.com/questions/6805756/is-it-possible-to-display-icons-in-a-popupmenu */ public static void forcePopupMenuToShowIcons(PopupMenu popup) { try { Field[] fields = popup.getClass().getDeclaredFields(); for (Field field : fields) { if ("mPopup".equals(field.getName())) { field.setAccessible(true); Object menuPopupHelper = field.get(popup); Class<?> classPopupHelper = Class.forName(menuPopupHelper.getClass().getName()); Method setForceIcons = classPopupHelper.getMethod("setForceShowIcon", boolean.class); setForceIcons.invoke(menuPopupHelper, true); break; } } } catch (Exception e) { e.printStackTrace(); } } }