/*
* Encog(tm) Core v3.4 - Java Version
* http://www.heatonresearch.com/encog/
* https://github.com/encog/encog-java-core
* Copyright 2008-2016 Heaton Research, Inc.
*
* Licensed 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.
*
* For more information on Heaton Research copyrights, licenses
* and trademarks visit:
* http://www.heatonresearch.com/copyright
*/
package org.encog.persist.source;
import org.encog.EncogError;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.InputStream;
/**
* A fallback stream that will attempt to read from the resource first, failing that, read from a file.
*/
public class ObtainFallbackStream implements ObtainInputStream {
/**
* The name of the file to read.
*/
private String datasetName;
/**
* The path.
*/
private String path;
/**
* The resources.
*/
private Class resources;
/**
* Construct the source.
* @param thePath The path.
* @param theDatasetName The name of the dataset.
* @param theResources Where to pull the resources from.
*/
public ObtainFallbackStream(String thePath, String theDatasetName, Class theResources) {
this.datasetName = theDatasetName;
this.path = thePath;
this.resources = theResources;
}
/**
* {@inheritDoc}
*/
@Override
public InputStream obtain() {
File target = null;
final InputStream istream = this.resources.getResourceAsStream("/"+this.datasetName);
if (istream == null) {
try {
target = new File(this.path,this.datasetName);
return new FileInputStream(target);
} catch (FileNotFoundException e) {
throw new EncogError("Cannot access data set, make sure the resources are available: " + target);
}
}
return istream;
}
}