opennlp.tools.formats.convert.AbstractToSentenceSampleStream 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.IOException;
import java.util.ArrayList;
import java.util.List;
import java.util.Objects;
import opennlp.tools.sentdetect.SentenceSample;
import opennlp.tools.tokenize.Detokenizer;
import opennlp.tools.util.FilterObjectStream;
import opennlp.tools.util.ObjectStream;
public abstract class AbstractToSentenceSampleStream extends
FilterObjectStream {
private final Detokenizer detokenizer;
private final int chunkSize;
/**
* @param detokenizer The {@link Detokenizer} to use. Must not be {@code null}.
* @param samples The {@link ObjectStream samples} as input. Must not be {@code null}.
* @param chunkSize The size of chunks. Must be equal to or greater than {@code 0}.
*
* @throws IllegalArgumentException Thrown if parameters are invalid.
*/
AbstractToSentenceSampleStream(Detokenizer detokenizer,
ObjectStream samples, int chunkSize) {
super(samples);
this.detokenizer = Objects.requireNonNull(detokenizer, "detokenizer must not be null");
if (chunkSize < 0) {
throw new IllegalArgumentException("chunkSize must be zero or larger but was " + chunkSize + "!");
}
if (chunkSize > 0) {
this.chunkSize = chunkSize;
}
else {
this.chunkSize = Integer.MAX_VALUE;
}
}
protected abstract String[] toSentence(T sample);
@Override
public SentenceSample read() throws IOException {
List sentences = new ArrayList<>();
T posSample;
int chunks = 0;
while ((posSample = samples.read()) != null && chunks < chunkSize) {
sentences.add(toSentence(posSample));
chunks++;
}
if (sentences.size() > 0) {
return new SentenceSample(detokenizer,
sentences.toArray(new String[sentences.size()][]));
}
else if (posSample != null) {
return read(); // filter out empty line
}
return null; // last sample was read
}
}