Java tutorial
/** * Copyright 2014 Kakao Corp. * * Redistribution and modification in source or binary forms are not permitted without specific prior written permission. * * 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. */ package com.kakao.helper; import java.util.ArrayList; import java.util.Date; import java.util.HashMap; import java.util.List; import java.util.Map; import org.json.JSONArray; import org.json.JSONException; import org.json.JSONObject; import android.content.Context; import android.content.SharedPreferences; import android.os.Bundle; public class SharedPreferencesCache { private static final String TAG = SharedPreferencesCache.class.getSimpleName(); private static final String JSON_VALUE_TYPE = "valueType"; private static final String JSON_VALUE = "value"; private static final String JSON_VALUE_ENUM_TYPE = "enumType"; private static final String TYPE_BOOLEAN = "bool"; private static final String TYPE_BOOLEAN_ARRAY = "bool[]"; private static final String TYPE_BYTE = "byte"; private static final String TYPE_BYTE_ARRAY = "byte[]"; private static final String TYPE_SHORT = "short"; private static final String TYPE_SHORT_ARRAY = "short[]"; private static final String TYPE_INTEGER = "int"; private static final String TYPE_INTEGER_ARRAY = "int[]"; private static final String TYPE_LONG = "long"; private static final String TYPE_LONG_ARRAY = "long[]"; private static final String TYPE_FLOAT = "float"; private static final String TYPE_FLOAT_ARRAY = "float[]"; private static final String TYPE_DOUBLE = "double"; private static final String TYPE_DOUBLE_ARRAY = "double[]"; private static final String TYPE_CHAR = "char"; private static final String TYPE_CHAR_ARRAY = "char[]"; private static final String TYPE_STRING = "string"; private static final String TYPE_STRING_LIST = "stringList"; private static final String TYPE_ENUM = "enum"; private final SharedPreferences file; private final Bundle memory = new Bundle(); public SharedPreferencesCache(Context context, final String cacheName) { Utility.notNull(context, "context"); Utility.notNull(cacheName, "cacheName"); Context applicationContext = context.getApplicationContext(); context = applicationContext != null ? applicationContext : context; this.file = context.getSharedPreferences(cacheName, Context.MODE_PRIVATE); } public synchronized void reloadAll() { Map<String, ?> allCachedEntries = file.getAll(); for (String key : allCachedEntries.keySet()) { try { deserializeKey(key); } catch (JSONException e) { Logger.getInstance().w(TAG, "Error reading cached value for key: '" + key + "' -- " + e); } } } public synchronized void save(final Bundle bundle) { Utility.notNull(bundle, "bundle"); SharedPreferences.Editor editor = file.edit(); for (String key : bundle.keySet()) { try { serializeKey(key, bundle, editor); } catch (JSONException e) { Logger.getInstance().w("Error processing value for key: " + key + ", e = " + e); return; } } boolean successfulCommit = editor.commit(); if (!successfulCommit) { Logger.getInstance().w("SharedPreferences.Editor.commit() was not successful"); } else { for (String key : bundle.keySet()) { try { deserializeKey(key); } catch (JSONException e) { Logger.getInstance().w("Error reading cached value for key: " + key + ", e = " + e); } } } } public synchronized void clear(final List<String> keysToClear) { SharedPreferences.Editor cacheEditor = file.edit(); for (String key : keysToClear) { cacheEditor.remove(key); } cacheEditor.commit(); for (String key : keysToClear) { memory.remove(key); } Logger.getInstance().i("Clearing keys : " + keysToClear); } public synchronized void clearAll() { file.edit().clear().commit(); memory.clear(); Logger.getInstance().i("Clearing all "); } public synchronized Map<String, String> getStringMap(final String keyPrefix) { reloadAll(); Map<String, String> properties = new HashMap<String, String>(); for (String key : memory.keySet()) { if (key.startsWith(keyPrefix)) { properties.put(key, (String) memory.get(key)); } } return properties; } public synchronized String getString(final String key) { String value = memory.getString(key); if (value == null) { try { deserializeKey(key); value = memory.getString(key); } catch (JSONException e) { Logger.getInstance().w("Error reading cached value for key: '" + key + "' -- " + e); } } return value; } public synchronized int getInt(final String key) { int value = memory.getInt(key, Integer.MIN_VALUE); if (value == Integer.MIN_VALUE) { try { deserializeKey(key); value = memory.getInt(key, Integer.MIN_VALUE); } catch (JSONException e) { Logger.getInstance().w("Error reading cached value for key: '" + key + "' -- " + e); } } return value; } public synchronized Long getLong(final String key) { long value = memory.getLong(key, Long.MIN_VALUE); if (value == Long.MIN_VALUE) { try { deserializeKey(key); value = memory.getLong(key, Long.MIN_VALUE); } catch (JSONException e) { Logger.getInstance().w("Error reading cached value for key: '" + key + "' -- " + e); } } return value; } public synchronized Date getDate(final String key) { long value = getLong(key); return (value == Long.MIN_VALUE) ? null : new Date(value); } private void serializeKey(String key, Bundle bundle, SharedPreferences.Editor editor) throws JSONException { Object value = bundle.get(key); if (value == null) { // Cannot serialize null values. return; } String supportedType = null; JSONArray jsonArray = null; JSONObject json = new JSONObject(); if (value instanceof Byte) { supportedType = TYPE_BYTE; json.put(JSON_VALUE, ((Byte) value).intValue()); } else if (value instanceof Short) { supportedType = TYPE_SHORT; json.put(JSON_VALUE, ((Short) value).intValue()); } else if (value instanceof Integer) { supportedType = TYPE_INTEGER; json.put(JSON_VALUE, ((Integer) value).intValue()); } else if (value instanceof Long) { supportedType = TYPE_LONG; json.put(JSON_VALUE, ((Long) value).longValue()); } else if (value instanceof Float) { supportedType = TYPE_FLOAT; json.put(JSON_VALUE, ((Float) value).doubleValue()); } else if (value instanceof Double) { supportedType = TYPE_DOUBLE; json.put(JSON_VALUE, ((Double) value).doubleValue()); } else if (value instanceof Boolean) { supportedType = TYPE_BOOLEAN; json.put(JSON_VALUE, ((Boolean) value).booleanValue()); } else if (value instanceof Character) { supportedType = TYPE_CHAR; json.put(JSON_VALUE, value.toString()); } else if (value instanceof String) { supportedType = TYPE_STRING; json.put(JSON_VALUE, value); } else if (value instanceof Enum<?>) { supportedType = TYPE_ENUM; json.put(JSON_VALUE, value.toString()); json.put(JSON_VALUE_ENUM_TYPE, value.getClass().getName()); } else { // Optimistically create a JSONArray. If not an array type, we can null // it out later jsonArray = new JSONArray(); if (value instanceof byte[]) { supportedType = TYPE_BYTE_ARRAY; for (byte v : (byte[]) value) { jsonArray.put((int) v); } } else if (value instanceof short[]) { supportedType = TYPE_SHORT_ARRAY; for (short v : (short[]) value) { jsonArray.put((int) v); } } else if (value instanceof int[]) { supportedType = TYPE_INTEGER_ARRAY; for (int v : (int[]) value) { jsonArray.put(v); } } else if (value instanceof long[]) { supportedType = TYPE_LONG_ARRAY; for (long v : (long[]) value) { jsonArray.put(v); } } else if (value instanceof float[]) { supportedType = TYPE_FLOAT_ARRAY; for (float v : (float[]) value) { jsonArray.put((double) v); } } else if (value instanceof double[]) { supportedType = TYPE_DOUBLE_ARRAY; for (double v : (double[]) value) { jsonArray.put(v); } } else if (value instanceof boolean[]) { supportedType = TYPE_BOOLEAN_ARRAY; for (boolean v : (boolean[]) value) { jsonArray.put(v); } } else if (value instanceof char[]) { supportedType = TYPE_CHAR_ARRAY; for (char v : (char[]) value) { jsonArray.put(String.valueOf(v)); } } else if (value instanceof List<?>) { supportedType = TYPE_STRING_LIST; @SuppressWarnings("unchecked") List<String> stringList = (List<String>) value; for (String v : stringList) { jsonArray.put((v == null) ? JSONObject.NULL : v); } } else { // Unsupported type. Clear out the array as a precaution even though // it is redundant with the null supportedType. jsonArray = null; } } if (supportedType != null) { json.put(JSON_VALUE_TYPE, supportedType); if (jsonArray != null) { // If we have an array, it has already been converted to JSON. So use // that instead. json.putOpt(JSON_VALUE, jsonArray); } String jsonString = json.toString(); editor.putString(key, jsonString); } } private void deserializeKey(String key) throws JSONException { String jsonString = file.getString(key, "{}"); JSONObject json = new JSONObject(jsonString); String valueType = json.getString(JSON_VALUE_TYPE); if (valueType.equals(TYPE_BOOLEAN)) { memory.putBoolean(key, json.getBoolean(JSON_VALUE)); } else if (valueType.equals(TYPE_BOOLEAN_ARRAY)) { JSONArray jsonArray = json.getJSONArray(JSON_VALUE); boolean[] array = new boolean[jsonArray.length()]; for (int i = 0; i < array.length; i++) { array[i] = jsonArray.getBoolean(i); } memory.putBooleanArray(key, array); } else if (valueType.equals(TYPE_BYTE)) { memory.putByte(key, (byte) json.getInt(JSON_VALUE)); } else if (valueType.equals(TYPE_BYTE_ARRAY)) { JSONArray jsonArray = json.getJSONArray(JSON_VALUE); byte[] array = new byte[jsonArray.length()]; for (int i = 0; i < array.length; i++) { array[i] = (byte) jsonArray.getInt(i); } memory.putByteArray(key, array); } else if (valueType.equals(TYPE_SHORT)) { memory.putShort(key, (short) json.getInt(JSON_VALUE)); } else if (valueType.equals(TYPE_SHORT_ARRAY)) { JSONArray jsonArray = json.getJSONArray(JSON_VALUE); short[] array = new short[jsonArray.length()]; for (int i = 0; i < array.length; i++) { array[i] = (short) jsonArray.getInt(i); } memory.putShortArray(key, array); } else if (valueType.equals(TYPE_INTEGER)) { memory.putInt(key, json.getInt(JSON_VALUE)); } else if (valueType.equals(TYPE_INTEGER_ARRAY)) { JSONArray jsonArray = json.getJSONArray(JSON_VALUE); int[] array = new int[jsonArray.length()]; for (int i = 0; i < array.length; i++) { array[i] = jsonArray.getInt(i); } memory.putIntArray(key, array); } else if (valueType.equals(TYPE_LONG)) { memory.putLong(key, json.getLong(JSON_VALUE)); } else if (valueType.equals(TYPE_LONG_ARRAY)) { JSONArray jsonArray = json.getJSONArray(JSON_VALUE); long[] array = new long[jsonArray.length()]; for (int i = 0; i < array.length; i++) { array[i] = jsonArray.getLong(i); } memory.putLongArray(key, array); } else if (valueType.equals(TYPE_FLOAT)) { memory.putFloat(key, (float) json.getDouble(JSON_VALUE)); } else if (valueType.equals(TYPE_FLOAT_ARRAY)) { JSONArray jsonArray = json.getJSONArray(JSON_VALUE); float[] array = new float[jsonArray.length()]; for (int i = 0; i < array.length; i++) { array[i] = (float) jsonArray.getDouble(i); } memory.putFloatArray(key, array); } else if (valueType.equals(TYPE_DOUBLE)) { memory.putDouble(key, json.getDouble(JSON_VALUE)); } else if (valueType.equals(TYPE_DOUBLE_ARRAY)) { JSONArray jsonArray = json.getJSONArray(JSON_VALUE); double[] array = new double[jsonArray.length()]; for (int i = 0; i < array.length; i++) { array[i] = jsonArray.getDouble(i); } memory.putDoubleArray(key, array); } else if (valueType.equals(TYPE_CHAR)) { String charString = json.getString(JSON_VALUE); if (charString != null && charString.length() == 1) { memory.putChar(key, charString.charAt(0)); } } else if (valueType.equals(TYPE_CHAR_ARRAY)) { JSONArray jsonArray = json.getJSONArray(JSON_VALUE); char[] array = new char[jsonArray.length()]; for (int i = 0; i < array.length; i++) { String charString = jsonArray.getString(i); if (charString != null && charString.length() == 1) { array[i] = charString.charAt(0); } } memory.putCharArray(key, array); } else if (valueType.equals(TYPE_STRING)) { memory.putString(key, json.getString(JSON_VALUE)); } else if (valueType.equals(TYPE_STRING_LIST)) { JSONArray jsonArray = json.getJSONArray(JSON_VALUE); int numStrings = jsonArray.length(); ArrayList<String> stringList = new ArrayList<String>(numStrings); for (int i = 0; i < numStrings; i++) { Object jsonStringValue = jsonArray.get(i); stringList.add(i, jsonStringValue == JSONObject.NULL ? null : (String) jsonStringValue); } memory.putStringArrayList(key, stringList); } else if (valueType.equals(TYPE_ENUM)) { try { String enumType = json.getString(JSON_VALUE_ENUM_TYPE); @SuppressWarnings({ "unchecked", "rawtypes" }) Class<? extends Enum> enumClass = (Class<? extends Enum>) Class.forName(enumType); @SuppressWarnings("unchecked") Enum<?> enumValue = Enum.valueOf(enumClass, json.getString(JSON_VALUE)); memory.putSerializable(key, enumValue); } catch (ClassNotFoundException e) { Logger.getInstance().w(TAG, "Error deserializing key '" + key + "' -- " + e); } catch (IllegalArgumentException e) { Logger.getInstance().w(TAG, "Error deserializing key '" + key + "' -- " + e); } } } }