001/** 002 * Copyright 2015 DuraSpace, Inc. 003 * 004 * Licensed under the Apache License, Version 2.0 (the "License"); 005 * you may not use this file except in compliance with the License. 006 * You may obtain a copy of the License at 007 * 008 * http://www.apache.org/licenses/LICENSE-2.0 009 * 010 * Unless required by applicable law or agreed to in writing, software 011 * distributed under the License is distributed on an "AS IS" BASIS, 012 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 013 * See the License for the specific language governing permissions and 014 * limitations under the License. 015 */ 016package org.fcrepo.kernel.api.services.functions; 017 018import static java.util.UUID.randomUUID; 019 020import java.util.stream.IntStream; 021import java.util.StringJoiner; 022 023/** 024 * Unique value minter that creates hierarchical IDs from a UUID 025 * 026 * @author awoods 027 * @author acoburn 028 */ 029public interface HierarchicalIdentifierSupplier extends UniqueValueSupplier { 030 031 static final int DEFAULT_LENGTH = 2; 032 static final int DEFAULT_COUNT = 4; 033 034 /** 035 * Mint a unique identifier as a UUID 036 * 037 * @return uuid 038 */ 039 default public String get() { 040 041 final String s = randomUUID().toString(); 042 final StringJoiner joiner = new StringJoiner("/", "", "/" + s); 043 044 IntStream.rangeClosed(0, DEFAULT_COUNT - 1) 045 .forEach(x -> joiner.add(s.substring(x * DEFAULT_LENGTH, (x + 1) * DEFAULT_LENGTH))); 046 047 return joiner.toString(); 048 } 049}