1 /*
2 * Copyright (c) 2001-2017, Zoltan Farkas All Rights Reserved.
3 *
4 * This library is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU Lesser General Public
6 * License as published by the Free Software Foundation; either
7 * version 2.1 of the License, or (at your option) any later version.
8 *
9 * This library is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 * GNU General Public License for more details.
13 *
14 * You should have received a copy of the GNU Lesser General Public
15 * License along with this program; if not, write to the Free Software
16 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
17 *
18 * Additionally licensed with:
19 *
20 * Licensed under the Apache License, Version 2.0 (the "License");
21 * you may not use this file except in compliance with the License.
22 * You may obtain a copy of the License at
23 *
24 * http://www.apache.org/licenses/LICENSE-2.0
25 *
26 * Unless required by applicable law or agreed to in writing, software
27 * distributed under the License is distributed on an "AS IS" BASIS,
28 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
29 * See the License for the specific language governing permissions and
30 * limitations under the License.
31 */
32 package org.spf4j.base;
33
34 import edu.umd.cs.findbugs.annotations.CleanupObligation;
35 import edu.umd.cs.findbugs.annotations.DischargesObligation;
36 import edu.umd.cs.findbugs.annotations.SuppressFBWarnings;
37 import java.io.Closeable;
38 import java.util.Iterator;
39 import java.util.Spliterators;
40 import java.util.stream.Stream;
41 import java.util.stream.StreamSupport;
42
43 /**
44 * need to extend java.io.Closeable so that jaxrs does not interfere.
45 * @author Zoltan Farkas
46 */
47 @CleanupObligation
48 public interface CloseableIterator<T> extends Iterator<T>, Closeable {
49
50 @DischargesObligation
51 void close();
52
53 static <T> CloseableIterator<T> from(final Iterator<T> it) {
54 return from(it, () -> { });
55 }
56
57 static <T> CloseableIterator<T> from(final Iterator<T> it, final AutoCloseable close) {
58 return new CloseableIterator<T>() {
59 @Override
60 @SuppressFBWarnings("EXS_EXCEPTION_SOFTENING_NO_CHECKED")
61 public void close() {
62 try {
63 close.close();
64 } catch (RuntimeException | Error e) {
65 throw e;
66 } catch (Exception ex) {
67 throw new RuntimeException(ex);
68 }
69 }
70
71 @Override
72 public boolean hasNext() {
73 return it.hasNext();
74 }
75
76 @Override
77 public T next() {
78 return it.next();
79 }
80
81 @Override
82 public void remove() {
83 it.remove();
84 }
85
86 };
87 }
88
89 default Stream<T> toStreamRemaining() {
90 return toStreamRemaining(false);
91 }
92
93 default Stream<T> toStreamRemaining(final boolean parallel) {
94 return StreamSupport.stream(Spliterators.spliteratorUnknownSize(this, 0), parallel).onClose(() -> this.close());
95 }
96
97 }