001package ca.uhn.fhir.parser.json;
002
003import java.util.Set;
004
005/*
006 * #%L
007 * HAPI FHIR - Core Library
008 * %%
009 * Copyright (C) 2014 - 2017 University Health Network
010 * %%
011 * Licensed under the Apache License, Version 2.0 (the "License");
012 * you may not use this file except in compliance with the License.
013 * You may obtain a copy of the License at
014 * 
015 *      http://www.apache.org/licenses/LICENSE-2.0
016 * 
017 * Unless required by applicable law or agreed to in writing, software
018 * distributed under the License is distributed on an "AS IS" BASIS,
019 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
020 * See the License for the specific language governing permissions and
021 * limitations under the License.
022 * #L%
023 */
024
025public abstract class JsonLikeObject extends JsonLikeValue {
026
027        @Override
028        public ValueType getJsonType() {
029                return ValueType.OBJECT;
030        }
031        
032        @Override
033        public ScalarType getDataType() {
034                return null;
035        }
036
037        @Override
038        public boolean isObject() {
039                return true;
040        }
041
042        @Override
043        public JsonLikeObject getAsObject() {
044                return this;
045        }
046
047        @Override
048        public String getAsString() {
049                return null;
050        }
051
052        public abstract Set<String> keySet ();
053        
054        public abstract JsonLikeValue get (String key);
055        
056        public String getString (String key) {
057                JsonLikeValue value = this.get(key);
058                if (null == value) {
059                        throw new NullPointerException("Json object missing element named \""+key+"\"");
060                }
061                return value.getAsString();
062        }
063        
064        public String getString (String key, String defaultValue) {
065                String result = defaultValue;
066                JsonLikeValue value = this.get(key);
067                if (value != null) {
068                        result = value.getAsString();
069                }
070                return result;
071        }
072}