Java tutorial
//package com.java2s; /******************************************************************************* * Copyright 2011-2013 Sergey Tarasevich * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. *******************************************************************************/ import android.content.Context; import android.os.Environment; import android.util.Log; import java.io.File; import java.io.IOException; public class Main { private static final String INDIVIDUAL_DIR_NAME = "uil-images"; public static File genDiscCacheFile(Context context, String imageUri) { File individualCacheDir = getIndividualCacheDirectory(context); String fileName = String.valueOf(imageUri.hashCode()); File file = new File(individualCacheDir, fileName); Long currentTime = System.currentTimeMillis(); file.setLastModified(currentTime); return file; } /** * Returns individual application cache directory (for only image caching from ImageLoader). Cache directory will be * created on SD card <i>("/Android/data/[app_package_name]/cache/uil-images")</i> if card is mounted. Else - * Android defines cache directory on device's file system. * * @param context Application context * @return Cache {@link File directory} */ public static File getIndividualCacheDirectory(Context context) { File cacheDir = getCacheDirectory(context); File individualCacheDir = new File(cacheDir, INDIVIDUAL_DIR_NAME); if (!individualCacheDir.exists()) { if (!individualCacheDir.mkdir()) { individualCacheDir = cacheDir; } } return individualCacheDir; } /** * Returns application cache directory. Cache directory will be created on SD card * <i>("/Android/data/[app_package_name]/cache")</i> if card is mounted. Else - Android defines cache directory on * device's file system. * * @param context Application context * @return Cache {@link File directory} */ public static File getCacheDirectory(Context context) { File appCacheDir = null; if (Environment.MEDIA_MOUNTED.equals(Environment.getExternalStorageState())) { appCacheDir = getExternalCacheDir(context); } if (appCacheDir == null) { appCacheDir = context.getCacheDir(); } return appCacheDir; } private static File getExternalCacheDir(Context context) { File dataDir = new File(new File(Environment.getExternalStorageDirectory(), "Android"), "data"); File appCacheDir = new File(new File(dataDir, context.getPackageName()), "cache"); if (!appCacheDir.exists()) { if (!appCacheDir.mkdirs()) { Log.w("SU", "Unable to create external cache directory"); return null; } try { new File(appCacheDir, ".nomedia").createNewFile(); } catch (IOException e) { Log.w("SU", "Can't create \".nomedia\" file in application external cache directory"); } } return appCacheDir; } }