Java tutorial
/** * Copyright 2010-present Facebook. * * 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.facebook.model; import android.annotation.SuppressLint; import org.json.JSONException; import org.json.JSONObject; import java.util.*; class JsonUtil { static void jsonObjectClear(JSONObject jsonObject) { @SuppressWarnings("unchecked") Iterator<String> keys = jsonObject.keys(); while (keys.hasNext()) { keys.next(); keys.remove(); } } static boolean jsonObjectContainsValue(JSONObject jsonObject, Object value) { @SuppressWarnings("unchecked") Iterator<String> keys = jsonObject.keys(); while (keys.hasNext()) { Object thisValue = jsonObject.opt(keys.next()); if (thisValue != null && thisValue.equals(value)) { return true; } } return false; } private final static class JSONObjectEntry implements Map.Entry<String, Object> { private final String key; private final Object value; JSONObjectEntry(String key, Object value) { this.key = key; this.value = value; } @SuppressLint("FieldGetter") @Override public String getKey() { return this.key; } @Override public Object getValue() { return this.value; } @Override public Object setValue(Object object) { throw new UnsupportedOperationException("JSONObjectEntry is immutable"); } } static Set<Map.Entry<String, Object>> jsonObjectEntrySet(JSONObject jsonObject) { HashSet<Map.Entry<String, Object>> result = new HashSet<Map.Entry<String, Object>>(); @SuppressWarnings("unchecked") Iterator<String> keys = jsonObject.keys(); while (keys.hasNext()) { String key = keys.next(); Object value = jsonObject.opt(key); result.add(new JSONObjectEntry(key, value)); } return result; } static Set<String> jsonObjectKeySet(JSONObject jsonObject) { HashSet<String> result = new HashSet<String>(); @SuppressWarnings("unchecked") Iterator<String> keys = jsonObject.keys(); while (keys.hasNext()) { result.add(keys.next()); } return result; } static void jsonObjectPutAll(JSONObject jsonObject, Map<String, Object> map) { Set<Map.Entry<String, Object>> entrySet = map.entrySet(); for (Map.Entry<String, Object> entry : entrySet) { try { jsonObject.putOpt(entry.getKey(), entry.getValue()); } catch (JSONException e) { throw new IllegalArgumentException(e); } } } static Collection<Object> jsonObjectValues(JSONObject jsonObject) { ArrayList<Object> result = new ArrayList<Object>(); @SuppressWarnings("unchecked") Iterator<String> keys = jsonObject.keys(); while (keys.hasNext()) { result.add(jsonObject.opt(keys.next())); } return result; } }