01: /* LineReadingIterator
02: *
03: * $Id: LineReadingIterator.java 4650 2006-09-25 18:09:42Z paul_jack $
04: *
05: * Created on Jul 27, 2004
06: *
07: * Copyright (C) 2004 Internet Archive.
08: *
09: * This file is part of the Heritrix web crawler (crawler.archive.org).
10: *
11: * Heritrix is free software; you can redistribute it and/or modify
12: * it under the terms of the GNU Lesser Public License as published by
13: * the Free Software Foundation; either version 2.1 of the License, or
14: * any later version.
15: *
16: * Heritrix is distributed in the hope that it will be useful,
17: * but WITHOUT ANY WARRANTY; without even the implied warranty of
18: * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
19: * GNU Lesser Public License for more details.
20: *
21: * You should have received a copy of the GNU Lesser Public License
22: * along with Heritrix; if not, write to the Free Software
23: * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
24: */
25: package org.archive.util.iterator;
26:
27: import java.io.BufferedReader;
28: import java.io.IOException;
29: import java.util.logging.Logger;
30:
31: /**
32: * Utility class providing an Iterator interface over line-oriented
33: * text input, as a thin wrapper over a BufferedReader.
34: *
35: * @author gojomo
36: */
37: public class LineReadingIterator extends LookaheadIterator<String> {
38: private static final Logger logger = Logger
39: .getLogger(LineReadingIterator.class.getName());
40:
41: protected BufferedReader reader = null;
42:
43: public LineReadingIterator(BufferedReader r) {
44: reader = r;
45: }
46:
47: /**
48: * Loads next line into lookahead spot
49: *
50: * @return whether any item was loaded into next field
51: */
52: protected boolean lookahead() {
53: try {
54: next = this .reader.readLine();
55: if (next == null) {
56: // TODO: make this close-on-exhaust optional?
57: reader.close();
58: }
59: return (next != null);
60: } catch (IOException e) {
61: logger.warning(e.toString());
62: return false;
63: }
64: }
65: }
|