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 java.io.IOException;
/** A TokenStream enumerates the sequence of tokens, either from
fields of a document or from query text.
<p>
This is an abstract class. Concrete subclasses are:
<ul>
<li>{@link Tokenizer}, a TokenStream
whose input is a Reader; and
<li>{@link TokenFilter}, a TokenStream
whose input is another TokenStream.
</ul>
*/
public abstract class TokenStream {
/** Returns the next token in the stream, or null at EOS. */
public abstract Token next() throws IOException;
/** Resets this stream to the beginning. This is an
* optional operation, so subclasses may or may not
* implement this method. Reset() is not needed for
* the standard indexing process. However, if the Tokens
* of a TokenStream are intended to be consumed more than
* once, it is neccessary to implement reset().
*/
public void reset() throws IOException {}
/** Releases resources associated with this stream. */
public void close() throws IOException {}
}
|