/* * Copyright (C) 2008 Google Inc. * * 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.google.gson; /** * A class representing a Json {@code null} value. * * @author Inderjeet Singh * @author Joel Leitch * @since 1.2 */ public final class JsonNull extends JsonElement { private static final JsonNull INSTANCE = new JsonNull(true); /** * @deprecated Instead, use the creation method, {@link #createJsonNull()}. */ @Deprecated public JsonNull() { // Do nothing } private JsonNull(boolean placeholder) { // Prevent instantiation } @Override protected void toString(StringBuilder sb) { sb.append("null"); } /** * All instances of JsonNull have the same hash code since they are indistinguishable */ @Override public int hashCode() { return JsonNull.class.hashCode(); } /** * All instances of JsonNull are the same */ @Override public boolean equals(Object other) { return other instanceof JsonNull; } /** * Creation method used to return an instance of a {@link JsonNull}. To reduce the memory * footprint, a single object has been created for this class; therefore the same instance is * being returned for each invocation of this method. * * @return a instance of a {@link JsonNull} */ public static JsonNull createJsonNull() { return INSTANCE; } }