/*
* 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.util.Iterator;
import gobblin.configuration.ConfigurationKeys;
/**
* An abstraction for downloading a file in a {@link FileBasedExtractor}. Subclasses are expected to download the file in
* the {@link #downloadFile(String)} method and return a record iterator. A {@link FileDownloader} can be set in a
* {@link FileBasedExtractor} by setting {@link ConfigurationKeys#SOURCE_FILEBASED_OPTIONAL_DOWNLOADER_CLASS} in the
* state.
*
* @param <D> record type in the file
*/
public abstract class FileDownloader<D> {
protected final FileBasedExtractor<?, ?> fileBasedExtractor;
public FileDownloader(FileBasedExtractor<?, ?> fileBasedExtractor) {
this.fileBasedExtractor = fileBasedExtractor;
}
/**
* Downloads the file at <code>filePath</code> using the {@link FileBasedExtractor#fsHelper} and returns an
* {@link Iterator} to the records
*
* @param filePath of the file to be downloaded
* @return An iterator to the records in the file
*/
public abstract Iterator<D> downloadFile(final String filePath) throws IOException;
}