001    /*
002     * Licensed to the Apache Software Foundation (ASF) under one
003     * or more contributor license agreements.  See the NOTICE file
004     * distributed with this work for additional information
005     * regarding copyright ownership.  The ASF licenses this file
006     * to you under the Apache License, Version 2.0 (the
007     * "License"); you may not use this file except in compliance
008     * with the License.  You may obtain a copy of the License at
009     *
010     *     http://www.apache.org/licenses/LICENSE-2.0
011     *
012     * Unless required by applicable law or agreed to in writing,
013     * software distributed under the License is distributed on an
014     * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
015     * KIND, either express or implied.  See the License for the
016     * specific language governing permissions and limitations
017     * under the License.
018     */
019    package org.apache.shiro.util;
020    
021    /**
022     * Generics-aware interface supporting the
023     * <a href="http://en.wikipedia.org/wiki/Factory_method_pattern">Factory Method</a> design pattern.
024     *
025     * @param <T> The type of the instance returned by the Factory implementation.
026     * @since 1.0
027     */
028    public interface Factory<T> {
029    
030        /**
031         * Returns an instance of the required type.  The implementation determines whether or not a new or cached
032         * instance is created every time this method is called.
033         *
034         * @return an instance of the required type.
035         */
036        T getInstance();
037    }