MinFulltextWordsFilter.java

/**
 * Copyright (C) 2013 Christian Kohlschütter (ckkohl79@gmail.com)
 *
 * Licensed 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 de.l3s.boilerpipe.filters.english;

import de.l3s.boilerpipe.BoilerpipeFilter;
import de.l3s.boilerpipe.BoilerpipeProcessingException;
import de.l3s.boilerpipe.document.TextBlock;
import de.l3s.boilerpipe.document.TextDocument;

/**
 * Keeps only those content blocks which contain at least k full-text words
 * (measured by {@link de.l3s.boilerpipe.filters.english.HeuristicFilterBase#getNumFullTextWords(TextBlock)}). k is 30 by default.
 * 
 * @author Christian Kohlschütter
 */
public final class MinFulltextWordsFilter extends HeuristicFilterBase implements BoilerpipeFilter {
    public static final MinFulltextWordsFilter DEFAULT_INSTANCE = new MinFulltextWordsFilter(
            30);
    private final int minWords;

    public static MinFulltextWordsFilter getDefaultInstance() {
        return DEFAULT_INSTANCE;
    }

    public MinFulltextWordsFilter(final int minWords) {
        this.minWords = minWords;
    }

    public boolean process(final TextDocument doc)
            throws BoilerpipeProcessingException {

        boolean changes = false;

        for (TextBlock tb : doc.getTextBlocks()) {
            if (!tb.isContent()) {
                continue;
            }
            if (getNumFullTextWords(tb) < minWords) {
                tb.setIsContent(false);
                changes = true;
            }

        }

        return changes;

    }
}