001/*
002 * nimbus-jose-jwt
003 *
004 * Copyright 2012-2016, Connect2id Ltd.
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.jose.crypto.bc;
019
020
021import org.bouncycastle.jce.provider.BouncyCastleProvider;
022
023
024/**
025 * BouncyCastle JCA provider singleton, intended to prevent memory leaks by
026 * ensuring a single instance is loaded at all times. Application code that
027 * needs a BouncyCastle JCA provider should use the {@link #getInstance()}
028 * method to obtain an instance.
029 *
030 * @author Vladimir Dzhuvinov
031 */
032public final class BouncyCastleProviderSingleton {
033
034
035        /**
036         * The BouncyCastle provider, lazily instantiated.
037         */
038        private static BouncyCastleProvider bouncyCastleProvider;
039
040
041        /**
042         * Prevents external instantiation.
043         */
044        private BouncyCastleProviderSingleton() { }
045
046
047        /**
048         * Returns a BouncyCastle JCA provider instance.
049         *
050         * @return The BouncyCastle JCA provider instance.
051         */
052        public static BouncyCastleProvider getInstance() {
053
054                if (bouncyCastleProvider != null) {
055
056                        return bouncyCastleProvider;
057
058                } else {
059                        bouncyCastleProvider = new BouncyCastleProvider();
060                        return bouncyCastleProvider;
061                }
062        }
063}