gson/com/google/gson/JsonNull.java

   1 /*
   2  * Copyright (C) 2008 Google Inc.
   3  *
   4  * Licensed under the Apache License, Version 2.0 (the "License");
   5  * you may not use this file except in compliance with the License.
   6  * You may obtain a copy of the License at
   7  *
   8  * http://www.apache.org/licenses/LICENSE-2.0
   9  *
  10  * Unless required by applicable law or agreed to in writing, software
  11  * distributed under the License is distributed on an "AS IS" BASIS,
  12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  13  * See the License for the specific language governing permissions and
  14  * limitations under the License.
  15  */
  16
  17 package com.google.gson;
  18
  19 /**
  20  * A class representing a Json {@code null} value.
  21  *
  22  * @author Inderjeet Singh
  23  * @author Joel Leitch
  24  * @since 1.2
  25  */
  26 public final class JsonNull extends JsonElement {
  27   /**
  28    * singleton for JsonNull
  29    *
  30    * @since 1.8
  31    */
  32   public static final JsonNull INSTANCE = new JsonNull();
  33
  34   /**
  35    * Creates a new JsonNull object.
  36    * Deprecated since Gson version 1.8. Use {@link #INSTANCE} instead
  37    */
  38   @Deprecated
  39   public JsonNull() {
  40     // Do nothing
  41   }
  42
  43   @Override
  44   JsonNull deepCopy() {
  45     return INSTANCE;
  46   }
  47
  48   /**
  49    * All instances of JsonNull have the same hash code since they are indistinguishable
  50    */
  51   @Override
  52   public int hashCode() {
  53     return JsonNull.class.hashCode();
  54   }
  55
  56   /**
  57    * All instances of JsonNull are the same
  58    */
  59   @Override
  60   public boolean equals(Object other) {
  61     return this == other || other instanceof JsonNull;
  62   }
  63 }