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 */
019package org.apache.shiro.crypto.hash.format;
020
021import org.apache.shiro.crypto.hash.Hash;
022
023/**
024 * A {@code HashFormat} is able to format a {@link Hash} instance into a well-defined formatted String.
025 * <p/>
026 * Note that not all HashFormat algorithms are reversible.  That is, they can't be parsed and reconstituted to the
027 * original Hash instance.
028 * <p/>
029 * The formats that <em>are</em> reversible however will be represented as {@link ParsableHashFormat} instances.
030 *
031 * @see ParsableHashFormat
032 * @since 1.2
033 */
034public interface HashFormat {
035
036    /**
037     * Returns a formatted string representing the specified Hash instance.
038     *
039     * @param hash the hash instance to format into a String.
040     * @return a formatted string representing the specified Hash instance.
041     * @throws NullPointerException if given parameter hash is {@code null}.
042     */
043    String format(Hash hash);
044}