Java tutorial
/* * Copyright 2014 KC Ochibili * * 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. */ /* * The "" character is not a comma, it is the SINGLE LOW-9 QUOTATION MARK unicode 201A * and unicode 2017 that are used for separating the items in a list. */ // Modified version of: https://github.com/kcochibili/TinyDB--Android-Shared-Preferences-Turbo // Added getListMat and putListMat methods package com.lauszus.facerecognitionapp; import java.io.File; import java.io.FileOutputStream; import java.io.IOException; import java.util.ArrayList; import java.util.Arrays; import java.util.Map; //import com.google.gson.Gson; import android.content.Context; import android.content.SharedPreferences; import android.graphics.Bitmap; import android.graphics.Bitmap.CompressFormat; import android.graphics.BitmapFactory; import android.os.Environment; import android.preference.PreferenceManager; import android.text.TextUtils; import android.util.Base64; import android.util.Log; import org.opencv.core.CvType; import org.opencv.core.Mat; public class TinyDB { private SharedPreferences preferences; private String DEFAULT_APP_IMAGEDATA_DIRECTORY; private String lastImagePath = ""; public TinyDB(Context appContext) { preferences = PreferenceManager.getDefaultSharedPreferences(appContext); } /** * Decodes the Bitmap from 'path' and returns it * @param path image path * @return the Bitmap from 'path' */ public Bitmap getImage(String path) { Bitmap bitmapFromPath = null; try { bitmapFromPath = BitmapFactory.decodeFile(path); } catch (Exception e) { // TODO: handle exception e.printStackTrace(); } return bitmapFromPath; } /** * Returns the String path of the last saved image * @return string path of the last saved image */ public String getSavedImagePath() { return lastImagePath; } /** * Saves 'theBitmap' into folder 'theFolder' with the name 'theImageName' * @param theFolder the folder path dir you want to save it to e.g "DropBox/WorkImages" * @param theImageName the name you want to assign to the image file e.g "MeAtLunch.png" * @param theBitmap the image you want to save as a Bitmap * @return returns the full path(file system address) of the saved image */ public String putImage(String theFolder, String theImageName, Bitmap theBitmap) { if (theFolder == null || theImageName == null || theBitmap == null) return null; this.DEFAULT_APP_IMAGEDATA_DIRECTORY = theFolder; String mFullPath = setupFullPath(theImageName); if (!mFullPath.equals("")) { lastImagePath = mFullPath; saveBitmap(mFullPath, theBitmap); } return mFullPath; } /** * Saves 'theBitmap' into 'fullPath' * @param fullPath full path of the image file e.g. "Images/MeAtLunch.png" * @param theBitmap the image you want to save as a Bitmap * @return true if image was saved, false otherwise */ public boolean putImageWithFullPath(String fullPath, Bitmap theBitmap) { return !(fullPath == null || theBitmap == null) && saveBitmap(fullPath, theBitmap); } /** * Creates the path for the image with name 'imageName' in DEFAULT_APP.. directory * @param imageName name of the image * @return the full path of the image. If it failed to create directory, return empty string */ private String setupFullPath(String imageName) { File mFolder = new File(Environment.getExternalStorageDirectory(), DEFAULT_APP_IMAGEDATA_DIRECTORY); if (isExternalStorageReadable() && isExternalStorageWritable() && !mFolder.exists()) { if (!mFolder.mkdirs()) { Log.e("ERROR", "Failed to setup folder"); return ""; } } return mFolder.getPath() + '/' + imageName; } /** * Saves the Bitmap as a PNG file at path 'fullPath' * @param fullPath path of the image file * @param bitmap the image as a Bitmap * @return true if it successfully saved, false otherwise */ private boolean saveBitmap(String fullPath, Bitmap bitmap) { if (fullPath == null || bitmap == null) return false; boolean fileCreated = false; boolean bitmapCompressed = false; boolean streamClosed = false; File imageFile = new File(fullPath); if (imageFile.exists()) if (!imageFile.delete()) return false; try { fileCreated = imageFile.createNewFile(); } catch (IOException e) { e.printStackTrace(); } FileOutputStream out = null; try { out = new FileOutputStream(imageFile); bitmapCompressed = bitmap.compress(CompressFormat.PNG, 100, out); } catch (Exception e) { e.printStackTrace(); bitmapCompressed = false; } finally { if (out != null) { try { out.flush(); out.close(); streamClosed = true; } catch (IOException e) { e.printStackTrace(); streamClosed = false; } } } return (fileCreated && bitmapCompressed && streamClosed); } // Getters /** * Get int value from SharedPreferences at 'key'. If key not found, return 'defaultValue' * @param key SharedPreferences key * @param defaultValue int value returned if key was not found * @return int value at 'key' or 'defaultValue' if key not found */ public int getInt(String key) { return preferences.getInt(key, 0); } /** * Get parsed ArrayList of Integers from SharedPreferences at 'key' * @param key SharedPreferences key * @return ArrayList of Integers */ public ArrayList<Integer> getListInt(String key) { String[] myList = TextUtils.split(preferences.getString(key, ""), ""); ArrayList<String> arrayToList = new ArrayList<String>(Arrays.asList(myList)); ArrayList<Integer> newList = new ArrayList<Integer>(); for (String item : arrayToList) newList.add(Integer.parseInt(item)); return newList; } /** * Get long value from SharedPreferences at 'key'. If key not found, return 'defaultValue' * @param key SharedPreferences key * @param defaultValue long value returned if key was not found * @return long value at 'key' or 'defaultValue' if key not found */ public long getLong(String key, long defaultValue) { return preferences.getLong(key, defaultValue); } /** * Get float value from SharedPreferences at 'key'. If key not found, return 'defaultValue' * @param key SharedPreferences key * @param defaultValue float value returned if key was not found * @return float value at 'key' or 'defaultValue' if key not found */ public float getFloat(String key) { return preferences.getFloat(key, 0); } /** * Get double value from SharedPreferences at 'key'. If exception thrown, return 'defaultValue' * @param key SharedPreferences key * @param defaultValue double value returned if exception is thrown * @return double value at 'key' or 'defaultValue' if exception is thrown */ public double getDouble(String key, double defaultValue) { String number = getString(key); try { return Double.parseDouble(number); } catch (NumberFormatException e) { return defaultValue; } } /** * Get parsed ArrayList of Double from SharedPreferences at 'key' * @param key SharedPreferences key * @return ArrayList of Double */ public ArrayList<Double> getListDouble(String key) { String[] myList = TextUtils.split(preferences.getString(key, ""), ""); ArrayList<String> arrayToList = new ArrayList<String>(Arrays.asList(myList)); ArrayList<Double> newList = new ArrayList<Double>(); for (String item : arrayToList) newList.add(Double.parseDouble(item)); return newList; } /** * Get String value from SharedPreferences at 'key'. If key not found, return "" * @param key SharedPreferences key * @return String value at 'key' or "" (empty String) if key not found */ public String getString(String key) { return preferences.getString(key, ""); } /** * Get parsed ArrayList of String from SharedPreferences at 'key' * @param key SharedPreferences key * @return ArrayList of String */ public ArrayList<String> getListString(String key) { return new ArrayList<String>(Arrays.asList(TextUtils.split(preferences.getString(key, ""), ""))); } /** * Get boolean value from SharedPreferences at 'key'. If key not found, return 'defaultValue' * @param key SharedPreferences key * @param defaultValue boolean value returned if key was not found * @return boolean value at 'key' or 'defaultValue' if key not found */ public boolean getBoolean(String key) { return preferences.getBoolean(key, false); } /** * Get parsed ArrayList of Boolean from SharedPreferences at 'key' * @param key SharedPreferences key * @return ArrayList of Boolean */ public ArrayList<Boolean> getListBoolean(String key) { ArrayList<String> myList = getListString(key); ArrayList<Boolean> newList = new ArrayList<Boolean>(); for (String item : myList) { if (item.equals("true")) { newList.add(true); } else { newList.add(false); } } return newList; } public ArrayList<Mat> getListMat(String key) { ArrayList<String> objStrings = getListString(key); ArrayList<Mat> objects = new ArrayList<Mat>(); for (String jObjString : objStrings) { byte[] data = Base64.decode(jObjString, Base64.DEFAULT); Mat mat = new Mat(data.length, 1, CvType.CV_8U); mat.put(0, 0, data); objects.add(mat); } return objects; } // public ArrayList<Object> getListObject(String key, Class<?> mClass){ // Gson gson = new Gson(); // // ArrayList<String> objStrings = getListString(key); // ArrayList<Object> objects = new ArrayList<Object>(); // // for(String jObjString : objStrings){ // Object value = gson.fromJson(jObjString, mClass); // objects.add(value); // } // return objects; // } // public Object getObject(String key, Class<?> classOfT){ // // String json = getString(key); // Object value = new Gson().fromJson(json, classOfT); // if (value == null) // throw new NullPointerException(); // return value; // } // Put methods /** * Put int value into SharedPreferences with 'key' and save * @param key SharedPreferences key * @param value int value to be added */ public void putInt(String key, int value) { checkForNullKey(key); preferences.edit().putInt(key, value).apply(); } /** * Put ArrayList of Integer into SharedPreferences with 'key' and save * @param key SharedPreferences key * @param intList ArrayList of Integer to be added */ public void putListInt(String key, ArrayList<Integer> intList) { checkForNullKey(key); Integer[] myIntList = intList.toArray(new Integer[intList.size()]); preferences.edit().putString(key, TextUtils.join("", myIntList)).apply(); } /** * Put long value into SharedPreferences with 'key' and save * @param key SharedPreferences key * @param value long value to be added */ public void putLong(String key, long value) { checkForNullKey(key); preferences.edit().putLong(key, value).apply(); } /** * Put float value into SharedPreferences with 'key' and save * @param key SharedPreferences key * @param value float value to be added */ public void putFloat(String key, float value) { checkForNullKey(key); preferences.edit().putFloat(key, value).apply(); } /** * Put double value into SharedPreferences with 'key' and save * @param key SharedPreferences key * @param value double value to be added */ public void putDouble(String key, double value) { checkForNullKey(key); putString(key, String.valueOf(value)); } /** * Put ArrayList of Double into SharedPreferences with 'key' and save * @param key SharedPreferences key * @param doubleList ArrayList of Double to be added */ public void putListDouble(String key, ArrayList<Double> doubleList) { checkForNullKey(key); Double[] myDoubleList = doubleList.toArray(new Double[doubleList.size()]); preferences.edit().putString(key, TextUtils.join("", myDoubleList)).apply(); } /** * Put String value into SharedPreferences with 'key' and save * @param key SharedPreferences key * @param value String value to be added */ public void putString(String key, String value) { checkForNullKey(key); checkForNullValue(value); preferences.edit().putString(key, value).apply(); } /** * Put ArrayList of String into SharedPreferences with 'key' and save * @param key SharedPreferences key * @param stringList ArrayList of String to be added */ public void putListString(String key, ArrayList<String> stringList) { checkForNullKey(key); String[] myStringList = stringList.toArray(new String[stringList.size()]); preferences.edit().putString(key, TextUtils.join("", myStringList)).apply(); } /** * Put boolean value into SharedPreferences with 'key' and save * @param key SharedPreferences key * @param value boolean value to be added */ public void putBoolean(String key, boolean value) { checkForNullKey(key); preferences.edit().putBoolean(key, value).apply(); } /** * Put ArrayList of Boolean into SharedPreferences with 'key' and save * @param key SharedPreferences key * @param boolList ArrayList of Boolean to be added */ public void putListBoolean(String key, ArrayList<Boolean> boolList) { checkForNullKey(key); ArrayList<String> newList = new ArrayList<String>(); for (Boolean item : boolList) { if (item) { newList.add("true"); } else { newList.add("false"); } } putListString(key, newList); } public void putListMat(String key, ArrayList<Mat> objArray) { checkForNullKey(key); ArrayList<String> objStrings = new ArrayList<String>(); for (Mat mat : objArray) { int size = (int) (mat.total() * mat.channels()); byte[] data = new byte[size]; mat.get(0, 0, data); String dataString = new String(Base64.encode(data, Base64.DEFAULT)); objStrings.add(dataString); } putListString(key, objStrings); } /** * Put ObJect any type into SharedPrefrences with 'key' and save * @param key SharedPreferences key * @param obj is the Object you want to put */ // public void putObject(String key, Object obj){ // checkForNullKey(key); // Gson gson = new Gson(); // putString(key, gson.toJson(obj)); // } // // public void putListObject(String key, ArrayList<Object> objArray){ // checkForNullKey(key); // Gson gson = new Gson(); // ArrayList<String> objStrings = new ArrayList<String>(); // for(Object obj : objArray){ // objStrings.add(gson.toJson(obj)); // } // putListString(key, objStrings); // } /** * Remove SharedPreferences item with 'key' * @param key SharedPreferences key */ public void remove(String key) { preferences.edit().remove(key).apply(); } /** * Delete image file at 'path' * @param path path of image file * @return true if it successfully deleted, false otherwise */ public boolean deleteImage(String path) { return new File(path).delete(); } /** * Clear SharedPreferences (remove everything) */ public void clear() { preferences.edit().clear().apply(); } /** * Retrieve all values from SharedPreferences. Do not modify collection return by method * @return a Map representing a list of key/value pairs from SharedPreferences */ public Map<String, ?> getAll() { return preferences.getAll(); } /** * Register SharedPreferences change listener * @param listener listener object of OnSharedPreferenceChangeListener */ public void registerOnSharedPreferenceChangeListener( SharedPreferences.OnSharedPreferenceChangeListener listener) { preferences.registerOnSharedPreferenceChangeListener(listener); } /** * Unregister SharedPreferences change listener * @param listener listener object of OnSharedPreferenceChangeListener to be unregistered */ public void unregisterOnSharedPreferenceChangeListener( SharedPreferences.OnSharedPreferenceChangeListener listener) { preferences.unregisterOnSharedPreferenceChangeListener(listener); } /** * Check if external storage is writable or not * @return true if writable, false otherwise */ public static boolean isExternalStorageWritable() { return Environment.MEDIA_MOUNTED.equals(Environment.getExternalStorageState()); } /** * Check if external storage is readable or not * @return true if readable, false otherwise */ public static boolean isExternalStorageReadable() { String state = Environment.getExternalStorageState(); return Environment.MEDIA_MOUNTED.equals(state) || Environment.MEDIA_MOUNTED_READ_ONLY.equals(state); } /** * null keys would corrupt the shared pref file and make them unreadable this is a preventive measure * @param the pref key */ public void checkForNullKey(String key) { if (key == null) { throw new NullPointerException(); } } /** * null keys would corrupt the shared pref file and make them unreadable this is a preventive measure * @param the pref key */ public void checkForNullValue(String value) { if (value == null) { throw new NullPointerException(); } } }