/**
* 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 org.apache.mahout.cf.taste.example.grouplens;
import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStreamWriter;
import java.io.Writer;
import java.net.URL;
import java.util.regex.Pattern;
import com.google.common.base.Charsets;
import com.google.common.io.Closeables;
import com.google.common.io.Files;
import com.google.common.io.InputSupplier;
import com.google.common.io.Resources;
import org.apache.mahout.cf.taste.impl.model.file.FileDataModel;
import org.apache.mahout.common.iterator.FileLineIterable;
public final class GroupLensDataModel extends FileDataModel {
private static final String COLON_DELIMTER = "::";
private static final Pattern COLON_DELIMITER_PATTERN = Pattern.compile(COLON_DELIMTER);
public GroupLensDataModel() throws IOException {
this(readResourceToTempFile("/org/apache/mahout/cf/taste/example/grouplens/ratings.dat"));
}
/**
* @param ratingsFile GroupLens ratings.dat file in its native format
* @throws IOException if an error occurs while reading or writing files
*/
public GroupLensDataModel(File ratingsFile) throws IOException {
super(convertGLFile(ratingsFile));
}
private static File convertGLFile(File originalFile) throws IOException {
// Now translate the file; remove commas, then convert "::" delimiter to comma
File resultFile = new File(new File(System.getProperty("java.io.tmpdir")), "ratings.txt");
if (resultFile.exists()) {
resultFile.delete();
}
Writer writer = null;
try {
writer = new OutputStreamWriter(new FileOutputStream(resultFile), Charsets.UTF_8);
for (String line : new FileLineIterable(originalFile, false)) {
int lastDelimiterStart = line.lastIndexOf(COLON_DELIMTER);
if (lastDelimiterStart < 0) {
throw new IOException("Unexpected input format on line: " + line);
}
String subLine = line.substring(0, lastDelimiterStart);
String convertedLine = COLON_DELIMITER_PATTERN.matcher(subLine).replaceAll(",");
writer.write(convertedLine);
writer.write('\n');
}
} catch (IOException ioe) {
resultFile.delete();
throw ioe;
} finally {
Closeables.close(writer, false);
}
return resultFile;
}
public static File readResourceToTempFile(String resourceName) throws IOException {
InputSupplier<? extends InputStream> inSupplier;
try {
URL resourceURL = Resources.getResource(GroupLensRecommender.class, resourceName);
inSupplier = Resources.newInputStreamSupplier(resourceURL);
} catch (IllegalArgumentException iae) {
File resourceFile = new File("src/main/java" + resourceName);
inSupplier = Files.newInputStreamSupplier(resourceFile);
}
File tempFile = File.createTempFile("taste", null);
tempFile.deleteOnExit();
Files.copy(inSupplier, tempFile);
return tempFile;
}
@Override
public String toString() {
return "GroupLensDataModel";
}
}