001/*
002 * Licensed to DuraSpace under one or more contributor license agreements.
003 * See the NOTICE file distributed with this work for additional information
004 * regarding copyright ownership.
005 *
006 * DuraSpace licenses this file to you under the Apache License,
007 * Version 2.0 (the "License"); you may not use this file except in
008 * compliance 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, software
013 * distributed under the License is distributed on an "AS IS" BASIS,
014 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
015 * See the License for the specific language governing permissions and
016 * limitations under the License.
017 */
018package org.fcrepo.kernel.api.services.functions;
019
020import static java.util.UUID.randomUUID;
021
022import java.util.stream.IntStream;
023import java.util.StringJoiner;
024
025/**
026 * Unique value minter that creates hierarchical IDs from a UUID
027 *
028 * @author awoods
029 * @author acoburn
030 */
031public interface HierarchicalIdentifierSupplier extends UniqueValueSupplier {
032
033    static final int DEFAULT_LENGTH = 2;
034    static final int DEFAULT_COUNT = 4;
035
036    /**
037     * Mint a unique identifier as a UUID
038     *
039     * @return uuid
040     */
041    @Override
042    default public String get() {
043
044        final String s = randomUUID().toString();
045        final StringJoiner joiner = new StringJoiner("/", "", "/" + s);
046
047        IntStream.rangeClosed(0, DEFAULT_COUNT - 1)
048                 .forEach(x -> joiner.add(s.substring(x * DEFAULT_LENGTH, (x + 1) * DEFAULT_LENGTH)));
049
050        return joiner.toString();
051    }
052}