1 /*
2 * This file is part of *** M y C o R e ***
3 * See http://www.mycore.de/ for details.
4 *
5 * MyCoRe is free software: you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License as published by
7 * the Free Software Foundation, either version 3 of the License, or
8 * (at your option) any later version.
9 *
10 * MyCoRe is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 * GNU General Public License for more details.
14 *
15 * You should have received a copy of the GNU General Public License
16 * along with MyCoRe. If not, see <http://www.gnu.org/licenses/>.
17 */
18
19 package org.mycore.pi.urn;
20
21 import java.util.Comparator;
22 import java.util.HashMap;
23 import java.util.List;
24 import java.util.Map;
25 import java.util.Objects;
26 import java.util.Optional;
27 import java.util.concurrent.atomic.AtomicInteger;
28 import java.util.function.Predicate;
29 import java.util.regex.Matcher;
30 import java.util.regex.Pattern;
31
32 import org.mycore.pi.MCRPIManager;
33 import org.mycore.pi.MCRPIRegistrationInfo;
34
35 /**
36 * A Generator which helps to generate a URN with a counter inside.
37 */
38 public abstract class MCRCountingDNBURNGenerator extends MCRDNBURNGenerator {
39
40 private static final Map<String, AtomicInteger> PATTERN_COUNT_MAP = new HashMap<>();
41
42 MCRCountingDNBURNGenerator() {
43 super();
44 }
45
46 protected AtomicInteger readCountFromDatabase(String countPattern) {
47 Pattern regExpPattern = Pattern.compile(countPattern);
48 Predicate<String> matching = regExpPattern.asPredicate();
49
50 List<MCRPIRegistrationInfo> list = MCRPIManager.getInstance()
51 .getList(MCRDNBURN.TYPE, -1, -1);
52
53 // extract the number of the PI
54 Optional<Integer> highestNumber = list.stream()
55 .map(MCRPIRegistrationInfo::getIdentifier)
56 .filter(matching)
57 .map(pi -> {
58 // extract the number of the PI
59 Matcher matcher = regExpPattern.matcher(pi);
60 if (matcher.find() && matcher.groupCount() == 1) {
61 String group = matcher.group(1);
62 return Integer.parseInt(group, 10);
63 } else {
64 return null;
65 }
66 }).filter(Objects::nonNull)
67 .min(Comparator.reverseOrder())
68 .map(n -> n + 1);
69 return new AtomicInteger(highestNumber.orElse(0));
70 }
71
72 /**
73 * Gets the count for a specific pattern and increase the internal counter. If there is no internal counter it will
74 * look into the Database and detect the highest count with the pattern.
75 *
76 * @param pattern a reg exp pattern which will be used to detect the highest count. The first group is the count.
77 * e.G. [0-9]+-mods-2017-([0-9][0-9][0-9][0-9])-[0-9] will match 31-mods-2017-0003-3 and the returned
78 * count will be 4 (3+1).
79 * @return the next count
80 */
81 public final synchronized int getCount(String pattern) {
82 AtomicInteger count = PATTERN_COUNT_MAP
83 .computeIfAbsent(pattern, this::readCountFromDatabase);
84
85 return count.getAndIncrement();
86 }
87 }