org.archive.util.iterator.LineReadingIterator Maven / Gradle / Ivy
/*
* This file is part of the Heritrix web crawler (crawler.archive.org).
*
* Licensed to the Internet Archive (IA) by one or more individual
* contributors.
*
* The IA licenses this file to You under the Apache License, Version 2.0
* (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.archive.util.iterator;
import java.io.BufferedReader;
import java.io.IOException;
import java.util.logging.Logger;
/**
* Utility class providing an Iterator interface over line-oriented
* text input, as a thin wrapper over a BufferedReader.
*
* @author gojomo
*/
public class LineReadingIterator extends LookaheadIterator implements CloseableIterator {
private static final Logger logger =
Logger.getLogger(LineReadingIterator.class.getName());
protected BufferedReader reader = null;
public LineReadingIterator(BufferedReader r) {
reader = r;
}
/**
* Loads next line into lookahead spot
*
* @return whether any item was loaded into next field
*/
protected boolean lookahead() {
try {
next = this.reader.readLine();
if(next == null) {
// TODO: make this close-on-exhaust optional?
reader.close();
}
return (next!=null);
} catch (IOException e) {
logger.warning(e.toString());
return false;
}
}
public void close() throws IOException {
if (reader != null) {
reader.close();
}
}
}