opennlp.tools.tokenize.TokenSampleStream 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.tokenize;
import java.io.IOException;
import opennlp.tools.util.FilterObjectStream;
import opennlp.tools.util.ObjectStream;
/**
* This class is a stream filter which reads in string encoded samples and creates
* {@link TokenSample}s out of them. The input string sample is tokenized if a
* whitespace or the special separator chars occur.
*
* Sample:
* "token1 token2 token3<SPLIT>token4"
* The tokens token1 and token2 are separated by a whitespace, token3 and token3
* are separated by the special character sequence, in this case the default
* split sequence.
*
* The sequence must be unique in the input string and is not escaped.
*/
public class TokenSampleStream extends FilterObjectStream {
private final String separatorChars;
public TokenSampleStream(ObjectStream sampleStrings, String separatorChars) {
super(sampleStrings);
if (sampleStrings == null) {
throw new IllegalArgumentException("sampleStrings must not be null!");
}
if (separatorChars == null) {
throw new IllegalArgumentException("separatorChars must not be null!");
}
this.separatorChars= separatorChars;
}
public TokenSampleStream(ObjectStream sentences) {
this(sentences, TokenSample.DEFAULT_SEPARATOR_CHARS);
}
public TokenSample read() throws IOException {
String sampleString = samples.read();
if (sampleString != null) {
return TokenSample.parse(sampleString, separatorChars);
}
else {
return null;
}
}
}