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/*
* COPIED FROM APACHE LUCENE 4.7.2
*
* Git URL: [email protected]:apache/lucene.git, tag: releases/lucene-solr/4.7.2, path: lucene/core/src/java
*
* (see https://issues.apache.org/jira/browse/OAK-10786 for details)
*/
package org.apache.lucene.analysis;
/*
* 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.
*/
import org.apache.lucene.util.AttributeSource;
import java.io.Reader;
import java.io.IOException;
/** A Tokenizer is a TokenStream whose input is a Reader.
This is an abstract class; subclasses must override {@link #incrementToken()}
NOTE: Subclasses overriding {@link #incrementToken()} must
call {@link AttributeSource#clearAttributes()} before
setting attributes.
*/
public abstract class Tokenizer extends TokenStream {
/** The text source for this Tokenizer. */
protected Reader input = ILLEGAL_STATE_READER;
/** Pending reader: not actually assigned to input until reset() */
private Reader inputPending = ILLEGAL_STATE_READER;
/** Construct a token stream processing the given input. */
protected Tokenizer(Reader input) {
if (input == null) {
throw new NullPointerException("input must not be null");
}
this.inputPending = input;
}
/** Construct a token stream processing the given input using the given AttributeFactory. */
protected Tokenizer(AttributeFactory factory, Reader input) {
super(factory);
if (input == null) {
throw new NullPointerException("input must not be null");
}
this.inputPending = input;
}
/**
* {@inheritDoc}
*
* NOTE:
* The default implementation closes the input Reader, so
* be sure to call super.close() when overriding this method.
*/
@Override
public void close() throws IOException {
input.close();
// LUCENE-2387: don't hold onto Reader after close, so
// GC can reclaim
inputPending = input = ILLEGAL_STATE_READER;
}
/** Return the corrected offset. If {@link #input} is a {@link CharFilter} subclass
* this method calls {@link CharFilter#correctOffset}, else returns currentOff.
* @param currentOff offset as seen in the output
* @return corrected offset based on the input
* @see CharFilter#correctOffset
*/
protected final int correctOffset(int currentOff) {
return (input instanceof CharFilter) ? ((CharFilter) input).correctOffset(currentOff) : currentOff;
}
/** Expert: Set a new reader on the Tokenizer. Typically, an
* analyzer (in its tokenStream method) will use
* this to re-use a previously created tokenizer. */
public final void setReader(Reader input) throws IOException {
if (input == null) {
throw new NullPointerException("input must not be null");
} else if (this.input != ILLEGAL_STATE_READER) {
throw new IllegalStateException("TokenStream contract violation: close() call missing");
}
this.inputPending = input;
assert setReaderTestPoint();
}
@Override
public void reset() throws IOException {
super.reset();
input = inputPending;
inputPending = ILLEGAL_STATE_READER;
}
// only used by assert, for testing
boolean setReaderTestPoint() {
return true;
}
private static final Reader ILLEGAL_STATE_READER = new Reader() {
@Override
public int read(char[] cbuf, int off, int len) {
throw new IllegalStateException("TokenStream contract violation: reset()/close() call missing, " +
"reset() called multiple times, or subclass does not call super.reset(). " +
"Please see Javadocs of TokenStream class for more information about the correct consuming workflow.");
}
@Override
public void close() {}
};
}