/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF 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 gobblin.source.extractor.filebased;
import java.io.IOException;
import java.io.InputStream;
import java.util.Iterator;
import lombok.extern.slf4j.Slf4j;
import org.apache.commons.io.IOUtils;
import gobblin.configuration.ConfigurationKeys;
/**
* A {@link FileDownloader} that downloads a single file and iterates line by line.
*
* @param <D> record type in the file
*/
@Slf4j
public class SingleFileDownloader<D> extends FileDownloader<D> {
public SingleFileDownloader(FileBasedExtractor<?, ?> fileBasedExtractor) {
super(fileBasedExtractor);
}
@SuppressWarnings("unchecked")
public Iterator<D> downloadFile(String file) throws IOException {
log.info("Beginning to download file: " + file);
try {
InputStream inputStream =
this.fileBasedExtractor.getCloser().register(this.fileBasedExtractor.getFsHelper().getFileStream(file));
Iterator<D> fileItr = (Iterator<D>) IOUtils.lineIterator(inputStream, ConfigurationKeys.DEFAULT_CHARSET_ENCODING);
if (this.fileBasedExtractor.isShouldSkipFirstRecord() && fileItr.hasNext()) {
fileItr.next();
}
return fileItr;
} catch (FileBasedHelperException e) {
throw new IOException("Exception while downloading file " + file + " with message " + e.getMessage(), e);
}
}
}