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.xsl;
20
21 import java.io.IOException;
22 import java.io.InputStream;
23 import java.util.Optional;
24
25 import javax.xml.transform.stream.StreamSource;
26
27 import org.mycore.common.MCRException;
28
29 /**
30 * A {@link StreamSource} that offers a lazy initialization to {@link #getInputStream()}.
31 *
32 * @author Thomas Scheffler (yagee)
33 */
34 public class MCRLazyStreamSource extends StreamSource {
35
36 private InputStreamSupplier inputStreamSupplier;
37
38 public MCRLazyStreamSource(InputStreamSupplier inputStreamSupplier, String systemId) {
39 super(systemId);
40 this.inputStreamSupplier = Optional.ofNullable(inputStreamSupplier).orElse(() -> null);
41 }
42
43 @Override
44 public void setInputStream(InputStream inputStream) {
45 inputStreamSupplier = () -> inputStream;
46 }
47
48 @Override
49 public InputStream getInputStream() {
50 try {
51 return inputStreamSupplier.get();
52 } catch (IOException e) {
53 throw new MCRException(e);
54 }
55 }
56
57 @FunctionalInterface
58 public interface InputStreamSupplier {
59 InputStream get() throws IOException;
60 }
61
62 }