org.apache.solr.analysis.TestBufferedTokenStream.java Source code

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Here is the source code for org.apache.solr.analysis.TestBufferedTokenStream.java

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/**
 * 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 org.apache.solr.analysis;

import org.apache.lucene.analysis.Token;
import org.apache.lucene.analysis.TokenStream;
import org.apache.lucene.analysis.Tokenizer;
import org.apache.lucene.analysis.core.WhitespaceTokenizer;
import org.apache.lucene.analysis.tokenattributes.CharTermAttribute;

import java.io.IOException;
import java.io.StringReader;

/**
 * Test that BufferedTokenStream behaves as advertised in subclasses.
 */
public class TestBufferedTokenStream extends BaseTokenTestCase {

    /** Example of a class implementing the rule "A" "B" => "Q" "B" */
    public static class AB_Q_Stream extends BufferedTokenStream {
        public AB_Q_Stream(TokenStream input) {
            super(input);
        }

        protected Token process(Token t) throws IOException {
            if ("A".equals(new String(t.buffer(), 0, t.length()))) {
                Token t2 = read();
                if (t2 != null && "B".equals(new String(t2.buffer(), 0, t2.length())))
                    t.setEmpty().append("Q");
                if (t2 != null)
                    pushBack(t2);
            }
            return t;
        }
    }

    /** Example of a class implementing "A" "B" => "A" "A" "B" */
    public static class AB_AAB_Stream extends BufferedTokenStream {
        public AB_AAB_Stream(TokenStream input) {
            super(input);
        }

        protected Token process(Token t) throws IOException {
            if ("A".equals(new String(t.buffer(), 0, t.length()))
                    && "B".equals(new String(peek(1).buffer(), 0, peek(1).length())))
                write((Token) t.clone());
            return t;
        }
    }

    public void testABQ() throws Exception {
        final String input = "How now A B brown A cow B like A B thing?";
        final String expected = "How now Q B brown A cow B like Q B thing?";
        TokenStream ts = new AB_Q_Stream(new WhitespaceTokenizer(DEFAULT_VERSION, new StringReader(input)));
        assertTokenStreamContents(ts, expected.split("\\s"));
    }

    public void testABAAB() throws Exception {
        final String input = "How now A B brown A cow B like A B thing?";
        final String expected = "How now A A B brown A cow B like A A B thing?";
        TokenStream ts = new AB_AAB_Stream(new WhitespaceTokenizer(DEFAULT_VERSION, new StringReader(input)));
        assertTokenStreamContents(ts, expected.split("\\s"));
    }

    public void testReset() throws Exception {
        final String input = "How now A B brown A cow B like A B thing?";
        Tokenizer tokenizer = new WhitespaceTokenizer(DEFAULT_VERSION, new StringReader(input));
        TokenStream ts = new AB_AAB_Stream(tokenizer);
        CharTermAttribute term = ts.addAttribute(CharTermAttribute.class);
        assertTrue(ts.incrementToken());
        assertEquals("How", term.toString());
        assertTrue(ts.incrementToken());
        assertEquals("now", term.toString());
        assertTrue(ts.incrementToken());
        assertEquals("A", term.toString());
        // reset back to input, 
        // if reset() does not work correctly then previous buffered tokens will remain 
        tokenizer.reset(new StringReader(input));
        ts.reset();
        assertTrue(ts.incrementToken());
        assertEquals("How", term.toString());
    }
}