001/*
002 * oauth2-oidc-sdk
003 *
004 * Copyright 2012-2016, Connect2id Ltd and contributors.
005 *
006 * Licensed under the Apache License, Version 2.0 (the "License"); you may not use
007 * this file except in compliance with the License. You may obtain a copy of the
008 * License at
009 *
010 *    http://www.apache.org/licenses/LICENSE-2.0
011 *
012 * Unless required by applicable law or agreed to in writing, software distributed
013 * under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR
014 * CONDITIONS OF ANY KIND, either express or implied. See the License for the
015 * specific language governing permissions and limitations under the License.
016 */
017
018package com.nimbusds.oauth2.sdk.util;
019
020
021import java.util.LinkedList;
022import java.util.List;
023
024import com.nimbusds.oauth2.sdk.ParseException;
025
026import net.minidev.json.parser.JSONParser;
027import net.minidev.json.writer.JsonReader;
028
029
030/**
031 * JSON helper methods.
032 */
033public final class JSONUtils {
034
035
036        /**
037         * Parses a JSON value.
038         *
039         * @param s The JSON string to parse. Must not be {@code null}.
040         *
041         * @return The JSON value.
042         *
043         * @throws ParseException If the string cannot be parsed to a JSON
044         *                        value.
045         */
046        public static Object parseJSON(final String s)
047                throws ParseException {
048
049                try {
050                        return new JSONParser(
051                                JSONParser.USE_HI_PRECISION_FLOAT |
052                                        JSONParser.ACCEPT_TAILLING_SPACE |
053                                        JSONParser.LIMIT_JSON_DEPTH
054                        ).parse(s);
055                } catch (net.minidev.json.parser.ParseException e) {
056                        throw new ParseException("Invalid JSON", e);
057                } catch (NullPointerException e) {
058                        throw new ParseException("The JSON string must not be null", e);
059                } catch (Exception e) {
060                        throw new ParseException("Unexpected exception: " + e.getMessage(), e);
061                } catch (Error e) {
062                        // Guard against unexpected java.lang.Error instances
063                        throw new ParseException("Unexpected error: " + e.getMessage(), e);
064                }
065        }
066
067
068        /**
069         * Parses a JSON value while keeping the order of JSON object members.
070         *
071         * @param s The JSON string to parse. Must not be {@code null}.
072         *
073         * @return The JSON value.
074         *
075         * @throws ParseException If the string cannot be parsed to a JSON
076         *                        value.
077         */
078        public static Object parseJSONKeepingOrder(final String s)
079                throws ParseException {
080
081                try {
082                        return new JSONParser(
083                                JSONParser.USE_HI_PRECISION_FLOAT |
084                                        JSONParser.ACCEPT_TAILLING_SPACE |
085                                        JSONParser.LIMIT_JSON_DEPTH
086                        ).parse(s, new JsonReader().DEFAULT_ORDERED);
087
088                } catch (net.minidev.json.parser.ParseException e) {
089                        throw new ParseException("Invalid JSON", e);
090                } catch (NullPointerException e) {
091                        throw new ParseException("The JSON string must not be null", e);
092                } catch (Exception e) {
093                        throw new ParseException("Unexpected exception: " + e.getMessage(), e);
094                } catch (Error e) {
095                        // Guard against unexpected java.lang.Error instances
096                        throw new ParseException("Unexpected error: " + e.getMessage(), e);
097                }
098        }
099        
100        
101        /**
102         * Casts an object.
103         *
104         * @param o     The object. Must not be {@code null}.
105         * @param clazz The expected class of the object. Must not be
106         *              {@code null}.
107         *
108         * @return The cast object.
109         *
110         * @throws ParseException If the object is not of the expected type.
111         */
112        @SuppressWarnings("unchecked")
113        public static <T> T to(final Object o, final Class<T> clazz)
114                throws ParseException {
115                
116                if (! clazz.isAssignableFrom(o.getClass()))
117                        throw new ParseException("Unexpected type: " + o.getClass());
118                
119                return (T)o;
120        }
121        
122        
123        /**
124         * Casts an object to a boolean.
125         *
126         * @param o The object. Must not be {@code null}.
127         *
128         * @return The boolean value.
129         *
130         * @throws ParseException If the object is not of the expected type.
131         */
132        public static boolean toBoolean(final Object o)
133                throws ParseException {
134                
135                return to(o, Boolean.class);
136        }
137        
138        
139        /**
140         * Casts an object to a number.
141         *
142         * @param o The object. Must not be {@code null}.
143         *
144         * @return The number.
145         *
146         * @throws ParseException If the object is not of the expected type.
147         */
148        public static Number toNumber(final Object o)
149                throws ParseException {
150                
151                return to(o, Number.class);
152        }
153        
154        
155        /**
156         * Casts an object to a string.
157         *
158         * @param o The object. Must not be {@code null}.
159         *
160         * @return The string.
161         *
162         * @throws ParseException If the object is not of the expected type.
163         */
164        public static String toString(final Object o)
165                throws ParseException {
166                
167                return to(o, String.class);
168        }
169        
170        
171        /**
172         * Casts an object to a list.
173         *
174         * @param o The object. Must not be {@code null}.
175         *
176         * @return The list.
177         *
178         * @throws ParseException If the object is not of the expected type.
179         */
180        public static List<?> toList(final Object o)
181                throws ParseException {
182                
183                return to(o, List.class);
184        }
185        
186        
187        /**
188         * Casts an object to a list then returns a string list copy of it
189         * casting each item to a string.
190         *
191         * @param o The object. Must not be {@code null}.
192         *
193         * @return The string list.
194         *
195         * @throws ParseException If the object is not of the expected type.
196         */
197        public static List<String> toStringList(final Object o)
198                throws ParseException {
199                
200                List<String> stringList = new LinkedList<>();
201                try {
202                        for (Object item: toList(o)) {
203                                stringList.add((String)item);
204                        }
205                } catch (ClassCastException e) {
206                        throw new ParseException("Item not a string");
207                }
208                return stringList;
209        }
210        
211        
212        /**
213         * Prevents instantiation.
214         */
215        private JSONUtils() {}
216}