001/*
002 * Licensed to the Apache Software Foundation (ASF) under one or more
003 * contributor license agreements.  See the NOTICE file distributed with
004 * this work for additional information regarding copyright ownership.
005 * The ASF licenses this file to You under the Apache License, Version 2.0
006 * (the "License"); you may not use this file except in compliance with
007 * the License.  You may obtain a copy of the License at
008 *
009 *      http://www.apache.org/licenses/LICENSE-2.0
010 *
011 * Unless required by applicable law or agreed to in writing, software
012 * distributed under the License is distributed on an "AS IS" BASIS,
013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
014 * See the License for the specific language governing permissions and
015 * limitations under the License.
016 */
017package org.apache.wicket.util.crypt;
018
019
020import org.apache.wicket.util.lang.Args;
021
022/**
023 * {@link ICryptFactory} decorator that caches the call to {@link ICryptFactory#newCrypt()}
024 * 
025 * @author Igor Vaynberg (ivaynberg)
026 */
027public class CryptFactoryCachingDecorator implements ICryptFactory
028{
029        private final ICryptFactory delegate;
030        private ICrypt cache;
031
032        /**
033         * Construct.
034         * 
035         * @param delegate
036         *            the crypt factory whose {@link ICryptFactory#newCrypt()} call will be cached
037         */
038        public CryptFactoryCachingDecorator(final ICryptFactory delegate)
039        {
040                Args.notNull(delegate, "delegate");
041                this.delegate = delegate;
042        }
043
044        @Override
045        public final ICrypt newCrypt()
046        {
047                if (cache == null)
048                {
049                        cache = delegate.newCrypt();
050                }
051                return cache;
052        }
053}