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/* * Copyright (C) 2014 SCVNGR, Inc. d/b/a LevelUp * * 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.scvngr.levelup.core.model.util; import android.support.annotation.NonNull; import android.support.annotation.Nullable; import com.scvngr.levelup.core.model.MonetaryValue; import com.scvngr.levelup.core.util.IsoDateUtils; import net.jcip.annotations.ThreadSafe; import org.json.JSONArray; import org.json.JSONException; import org.json.JSONObject; import java.text.ParseException; import java.util.Date; import java.util.HashSet; import java.util.Locale; import java.util.Set; import java.util.TimeZone; /** * Helper class to work with {@link JSONObject} and avoid its bugs. * <http://code.google.com/p/android/issues/detail?id=13830>. */ @ThreadSafe public final class JsonUtils { /** * Helper method that gets an optional nullable {@link Long} value from the {@link JSONObject}. * * @param json the {@link JSONObject}. * @param key the key in {@code json}. * @return {@link Long} mapping for {@code key} in {@code json} or {@code null} if no mapping * exists. */ @Nullable public static Long optLongNullable(@NonNull final JSONObject json, @NonNull final String key) { if (json.isNull(key)) { return null; } return json.optLong(key); } /** * Helper method that doesn't return some fake version of null if the string is null, it returns * null. * * @param json the {@link JSONObject}. * @param key the key in {@code json}. * @return {@link String} mapping for {@code key} in {@code json} or {@code null} if no mapping * exists. */ @Nullable public static String optString(@NonNull final JSONObject json, @NonNull final String key) { String value = null; if (!json.isNull(key)) { value = json.optString(key, null); } return value; } /** * Loads a {@link Date}. * * @param json the object to read from. * @param key the key in {@code json}. * @return A parsed {@link Date} or {@code null} if either the key is not present or is set to * {@code null}. * @throws JSONException if the date could not be parsed. */ @Nullable /* package */static Date optDate(@NonNull final JSONObject json, @NonNull final String key) throws JSONException { Date value = null; if (!json.isNull(key)) { try { value = IsoDateUtils.parseIsoDatetime(json.getString(key), TimeZone.getDefault()); } catch (final ParseException e) { final JSONException jsonException = new JSONException("could not parse datetime"); jsonException.initCause(e); throw jsonException; } } return value; } /** * Loads a {@link Set} of {@link Integer} from a {@link JSONArray} of integers. * * @param json the object to read from. * @param key the key in {@code json}. * @return a set of integers loaded from the array of integers at the given {@code key} or * {@code null} if either the key is not present or is set to {@code null}. * @throws JSONException if the array contents aren't integers. */ @Nullable public static Set<Integer> optIntegerSet(@NonNull final JSONObject json, @NonNull final String key) throws JSONException { Set<Integer> result = null; if (!json.isNull(key)) { final JSONArray array = json.optJSONArray(key); if (null != array) { final int count = array.length(); result = new HashSet<Integer>(count); for (int i = 0; i < count; i++) { result.add(array.getInt(i)); } } } return result; } /** * Loads a {@link Set} of {@link String}s from a {@link JSONArray} of strings. * * @param json the object to read from. * @param key the key in {@code json}. * @return a set of strings loaded from the array of strings at the given {@code key} or * {@code null} if either the key is not present or is set to {@code null}. * @throws JSONException if the array contents aren't strings. */ @Nullable public static Set<String> optStringSet(@NonNull final JSONObject json, @NonNull final String key) throws JSONException { Set<String> result = null; if (!json.isNull(key)) { final JSONArray array = json.optJSONArray(key); if (null != array) { final int count = array.length(); result = new HashSet<String>(count); for (int i = 0; i < count; i++) { result.add(array.getString(i)); } } } return result; } /** * Gets an optional {@link MonetaryValue} object from the JSON at the key passed. * * @param json the {@link JSONObject} to get the {@link MonetaryValue} from. * @param key the key in the {@link JSONObject} to get the {@link MonetaryValue} from. * @return a {@link MonetaryValue} from the parsed long or null. * @throws JSONException if the parsing fails. */ @Nullable public static MonetaryValue optMonetaryValue(@NonNull final JSONObject json, @NonNull final String key) throws JSONException { final MonetaryValue value; final Long amount = json.optLong(key, Long.MIN_VALUE); if (Long.MIN_VALUE != amount) { value = new MonetaryValue(amount); } else { value = null; } return value; } /** * Gets a required {@link MonetaryValue} object from the JSON at the key passed or throws a * {@link JSONException} if it's missing. * * @param json the {@link JSONObject} to get the {@link MonetaryValue} from. * @param key the key in the {@link JSONObject} to get the {@link MonetaryValue} from. * @return a {@link MonetaryValue} from the parsed long. * @throws JSONException if the parsing fails. */ @NonNull public static MonetaryValue getMonetaryValue(@NonNull final JSONObject json, @NonNull final String key) throws JSONException { final MonetaryValue value = optMonetaryValue(json, key); if (null == value) { throw new JSONException(String.format(Locale.US, "key %s is required.", key)); } return value; } /** * Private constructor prevents instantiation. * * @throws UnsupportedOperationException because this class cannot be instantiated. */ private JsonUtils() { throw new UnsupportedOperationException("This class is non-instantiable"); } }