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}