001package com.nimbusds.jose;
002
003
004import net.jcip.annotations.Immutable;
005
006import net.minidev.json.JSONAware;
007import net.minidev.json.JSONObject;
008
009
010/**
011 * The base class for algorithm names, with optional implementation 
012 * requirement. This class is immutable.
013 *
014 * <p>Includes constants for the following standard algorithm names:
015 *
016 * <ul>
017 *     <li>{@link #NONE none}
018 * </ul>
019 *
020 * @author Vladimir Dzhuvinov 
021 * @version 2013-03-27
022 */
023@Immutable
024public class Algorithm implements JSONAware {
025
026
027        /**
028         * No algorithm (unsecured JOSE object without signature / encryption).
029         */
030        public static final Algorithm NONE = new Algorithm("none", Requirement.REQUIRED);
031
032
033        /**
034         * The algorithm name.
035         */
036        private final String name;
037
038
039        /**
040         * The implementation requirement, {@code null} if not known.
041         */
042        private final Requirement requirement;
043
044
045        /**
046         * Creates a new JOSE algorithm name.
047         *
048         * @param name The algorithm name. Must not be {@code null}.
049         * @param req  The implementation requirement, {@code null} if not 
050         *             known.
051         */
052        public Algorithm(final String name, final Requirement req) {
053
054                if (name == null) {
055
056                        throw new IllegalArgumentException("The algorithm name must not be null");
057                }
058
059                this.name = name;
060
061                requirement = req;
062        }
063
064
065        /**
066         * Creates a new JOSE algorithm name.
067         *
068         * @param name The algorithm name. Must not be {@code null}.
069         */
070        public Algorithm(final String name) {
071
072                this(name, null);
073        }
074
075
076        /**
077         * Gets the name of this algorithm.
078         *
079         * @return The algorithm name.
080         */
081        public final String getName() {
082
083                return name;
084        }
085
086
087        /**
088         * Gets the implementation requirement of this algorithm.
089         *
090         * @return The implementation requirement, {@code null} if not known.
091         */
092        public final Requirement getRequirement() {
093
094                return requirement;
095        }
096
097
098        /**
099         * Overrides {@code Object.hashCode()}.
100         *
101         * @return The object hash code.
102         */
103        @Override
104        public final int hashCode() {
105
106                return name.hashCode();
107        }
108
109
110        /**
111         * Overrides {@code Object.equals()}.
112         *
113         * @param object The object to compare to.
114         *
115         * @return {@code true} if the objects have the same value, otherwise
116         *         {@code false}.
117         */
118        @Override
119        public boolean equals(final Object object) {
120
121                return object != null && 
122                       object instanceof Algorithm && 
123                       this.toString().equals(object.toString());
124        }
125
126
127        /**
128         * Returns the string representation of this algorithm.
129         *
130         * @see #getName
131         *
132         * @return The string representation.
133         */
134        @Override
135        public final String toString() {
136
137                return name;
138        }
139
140
141        /**
142         * Returns the JSON string representation of this algorithm.
143         * 
144         * @return The JSON string representation.
145         */
146        @Override
147        public final String toJSONString() {
148
149                return "\"" + JSONObject.escape(name) + '"';
150        }
151}