code: /*
   * 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 tools.com.google.gson;
  
  import tools.com.google.gson.internal.LinkedTreeMap;
  
  import java.util.Map;
  import java.util.Set;
  
  /**
   * A class representing an object type in Json. An object consists of name-value pairs where names
   * are strings, and values are any other type of {@link JsonElement}. This allows for a creating a
   * tree of JsonElements. The member elements of this object are maintained in order they were added.
   *
   * @author Inderjeet Singh
   * @author Joel Leitch
   */
  public final class JsonObject extends JsonElement {
    private final LinkedTreeMap<String, JsonElement> members =
        new LinkedTreeMap<String, JsonElement>();
  
    /**
     * Creates a deep copy of this element and all its children
     * @since 2.8.2
     */
    @Override
    public JsonObject deepCopy() {
      JsonObject result = new JsonObject();
      for (Map.Entry<String, JsonElement> entry : members.entrySet()) {
        result.add(entry.getKey(), entry.getValue().deepCopy());
      }
      return result;
    }
  
    /**
     * Adds a member, which is a name-value pair, to self. The name must be a String, but the value
     * can be an arbitrary JsonElement, thereby allowing you to build a full tree of JsonElements
     * rooted at this node.
     *
     * @param property name of the member.
     * @param value the member object.
     */
    public void add(String property, JsonElement value) {
      if (value == null) {
        value = JsonNull.INSTANCE;
      }
      members.put(property, value);
    }
  
    /**
     * Removes the {@code property} from this {@link JsonObject}.
     *
     * @param property name of the member that should be removed.
     * @return the {@link JsonElement} object that is being removed.
     * @since 1.3
     */
    public JsonElement remove(String property) {
      return members.remove(property);
    }
  
    /**
     * Convenience method to add a primitive member. The specified value is converted to a
     * JsonPrimitive of String.
     *
     * @param property name of the member.
     * @param value the string value associated with the member.
     */
    public void addProperty(String property, String value) {
      add(property, createJsonElement(value));
    }
  
    /**
     * Convenience method to add a primitive member. The specified value is converted to a
     * JsonPrimitive of Number.
     *
     * @param property name of the member.
     * @param value the number value associated with the member.
     */
    public void addProperty(String property, Number value) {
      add(property, createJsonElement(value));
    }
  
    /**
     * Convenience method to add a boolean member. The specified value is converted to a
     * JsonPrimitive of Boolean.
     *
     * @param property name of the member.
     * @param value the number value associated with the member.
     */
    public void addProperty(String property, Boolean value) {
      add(property, createJsonElement(value));
    }
  
    /**
     * Convenience method to add a char member. The specified value is converted to a
     * JsonPrimitive of Character.
     *
     * @param property name of the member.
     * @param value the number value associated with the member.
     */
    public void addProperty(String property, Character value) {
      add(property, createJsonElement(value));
    }
  
    /**
     * Creates the proper {@link JsonElement} object from the given {@code value} object.
     *
     * @param value the object to generate the {@link JsonElement} for
     * @return a {@link JsonPrimitive} if the {@code value} is not null, otherwise a {@link JsonNull}
     */
    private JsonElement createJsonElement(Object value) {
      return value == null ? JsonNull.INSTANCE : new JsonPrimitive(value);
    }
  
    /**
     * Returns a set of members of this object. The set is ordered, and the order is in which the
     * elements were added.
     *
     * @return a set of members of this object.
     */
    public Set<Map.Entry<String, JsonElement>> entrySet() {
      return members.entrySet();
    }
  
    /**
     * Returns a set of members key values.
     *
     * @return a set of member keys as Strings
     * @since 2.8.1
     */
    public Set<String> keySet() {
      return members.keySet();
    }
  
    /**
     * Returns the number of key/value pairs in the object.
     *
     * @return the number of key/value pairs in the object.
     */
    public int size() {
      return members.size();
    }
  
    /**
     * Convenience method to check if a member with the specified name is present in this object.
     *
     * @param memberName name of the member that is being checked for presence.
     * @return true if there is a member with the specified name, false otherwise.
     */
    public boolean has(String memberName) {
      return members.containsKey(memberName);
    }
  
    /**
     * Returns the member with the specified name.
     *
     * @param memberName name of the member that is being requested.
     * @return the member matching the name. Null if no such member exists.
     */
    public JsonElement get(String memberName) {
      return members.get(memberName);
    }
  
    /**
     * Convenience method to get the specified member as a JsonPrimitive element.
     *
     * @param memberName name of the member being requested.
     * @return the JsonPrimitive corresponding to the specified member.
     */
    public JsonPrimitive getAsJsonPrimitive(String memberName) {
      return (JsonPrimitive) members.get(memberName);
    }
  
    /**
     * Convenience method to get the specified member as a JsonArray.
     *
     * @param memberName name of the member being requested.
     * @return the JsonArray corresponding to the specified member.
     */
    public JsonArray getAsJsonArray(String memberName) {
      return (JsonArray) members.get(memberName);
    }
  
    /**
     * Convenience method to get the specified member as a JsonObject.
     *
     * @param memberName name of the member being requested.
     * @return the JsonObject corresponding to the specified member.
     */
    public JsonObject getAsJsonObject(String memberName) {
      return (JsonObject) members.get(memberName);
    }
  
    @Override
    public boolean equals(Object o) {
      return (o == this) || (o instanceof JsonObject
          && ((JsonObject) o).members.equals(members));
    }
  
    @Override
    public int hashCode() {
      return members.hashCode();
    }
  }
  