fmpp.dataloaders.FileDataLoader Maven / Gradle / Ivy
/*
* Copyright 2014 Attila Szegedi, Daniel Dekany, Jonathan Revusky
*
* 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.
*/
package fmpp.dataloaders;
import java.io.File;
import java.io.FileInputStream;
import java.io.InputStream;
import java.util.List;
import fmpp.Engine;
import fmpp.tdd.DataLoader;
/**
* Ancestor of data loaders that create the result based on a file.
* The first argument of the data loader will be the path of the file.
* If the path is a relative path, then it will be relative to the data root
* directory (an engine level setting), or if data root is null, then relative
* to the working directory (OS facility). The path can use slash (/) instead
* of the OS specific separator char.
*/
public abstract class FileDataLoader implements DataLoader {
protected Engine engine;
protected List args;
protected File dataFile;
public Object load(Engine engine, List args) throws Exception {
this.engine = engine;
this.args = args;
if (args.size() < 1) {
throw new IllegalArgumentException(
"At least 1 argument (file name) needed");
}
Object obj = args.get(0);
if (!(obj instanceof String)) {
throw new IllegalArgumentException(
"The 1st argument (file name) must be a string.");
}
String path = (String) obj;
path = path.replace('/', File.separatorChar);
dataFile = new File(path);
if (!dataFile.isAbsolute()) {
dataFile = new File(engine.getDataRoot(), path);
}
InputStream in = new FileInputStream(dataFile);
try {
return load(in);
} finally {
in.close();
}
}
/**
* FileDataLoader
subclasess override this method to parse
* the file.
*/
protected abstract Object load(InputStream data) throws Exception;
}