opennlp.tools.formats.convert.FileToStringSampleStream Maven / Gradle / Ivy
/*
* 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 opennlp.tools.formats.convert;
import java.io.File;
import java.io.IOException;
import java.io.Reader;
import java.nio.charset.Charset;
import java.nio.file.Files;
import opennlp.tools.util.FilterObjectStream;
import opennlp.tools.util.ObjectStream;
/**
* Provides the ability to read the contents of files
* contained in an object stream of files.
*/
public class FileToStringSampleStream extends FilterObjectStream {
private final Charset encoding;
/**
* Initializes a {@link FileToStringSampleStream}.
*
* @param samples The {@link ObjectStream} containing the files.
* @param encoding The {@link Charset} encoding of the files.
*/
public FileToStringSampleStream(ObjectStream samples, Charset encoding) {
super(samples);
this.encoding = encoding;
}
/**
* Reads the contents of a {@code textFile} to a string.
*
* @param textFile The {@link File} to read.
* @param encoding The {@link Charset} of the {@code textFile}.
*
* @return The string contents of the file.
* @throws IOException Thrown if the file could not be read.
*/
private static String readFile(File textFile, Charset encoding) throws IOException {
StringBuilder text = new StringBuilder();
try (Reader in = Files.newBufferedReader(textFile.toPath(), encoding)) {
char[] buffer = new char[1024];
int length;
while ((length = in.read(buffer, 0, buffer.length)) > 0) {
text.append(buffer, 0, length);
}
}
return text.toString();
}
@Override
public String read() throws IOException {
File sampleFile = samples.read();
if (sampleFile != null) {
return readFile(sampleFile, encoding);
}
else {
return null;
}
}
}