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.common.content.transformer;
20
21 import java.util.HashMap;
22
23 import org.mycore.common.config.MCRConfiguration2;
24
25 /**
26 * Creates and returns MCRContentTransformer instances by their ID.
27 *
28 * @author Frank L\u00FCtzenkirchen
29 */
30 public class MCRContentTransformerFactory {
31
32 /** Map of transformer instances by ID */
33 private static HashMap<String, MCRContentTransformer> transformers = new HashMap<>();
34
35 /**
36 * Returns the transformer with the given ID. If the transformer is not instantiated yet,
37 * it is created and initialized.
38 */
39 public static MCRContentTransformer getTransformer(String id) {
40 if (transformers.containsKey(id)) {
41 return transformers.get(id);
42 } else {
43 return buildTransformer(id);
44 }
45 }
46
47 /**
48 * Creates and initializes the transformer with the given ID.
49 */
50 private static synchronized MCRContentTransformer buildTransformer(String id) {
51 String property = "MCR.ContentTransformer." + id + ".Class";
52 if (MCRConfiguration2.getString(property).isEmpty()
53 && MCRConfiguration2.getString("MCR.ContentTransformer." + id + ".Stylesheet").isEmpty()) {
54 //check for reasonable default:
55 return null;
56 }
57 MCRContentTransformer transformer = MCRConfiguration2.<MCRContentTransformer>getInstanceOf(property)
58 .orElseGet(MCRXSLTransformer::new);
59 transformer.init(id);
60 transformers.put(id, transformer);
61 return transformer;
62 }
63 }