edu.cmu.cs.lti.ark.fn.parsing.FEDict.java Source code

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Here is the source code for edu.cmu.cs.lti.ark.fn.parsing.FEDict.java

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/*******************************************************************************
 * Copyright (c) 2011 Dipanjan Das 
 * Language Technologies Institute, 
 * Carnegie Mellon University, 
 * All Rights Reserved.
 * 
 * FEDict.java is part of SEMAFOR 2.0.
 * 
 * SEMAFOR 2.0 is free software: you can redistribute it and/or modify  it
 * under the terms of the GNU General Public License as published by the
 * Free Software Foundation, either version 3 of the License, or 
 * (at your option) any later version.
 * 
 * SEMAFOR 2.0 is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
 * See the GNU General Public License for more details. 
 * 
 * You should have received a copy of the GNU General Public License along
 * with SEMAFOR 2.0.  If not, see <http://www.gnu.org/licenses/>.
 ******************************************************************************/
package edu.cmu.cs.lti.ark.fn.parsing;

import com.google.common.io.Files;
import com.google.common.io.InputSupplier;
import edu.cmu.cs.lti.ark.util.SerializedObjects;
import gnu.trove.THashSet;

import java.io.*;
import java.util.Map;

/**
 * A map from frames to their frame elements
 */
public class FEDict {
    public static final String DEFAULT_FILENAME = "framenet.frame.element.map";

    private Map<String, THashSet<String>> frameElementsForFrame;

    public static class LoadingException extends IOException {
        public LoadingException(Exception e) {
            super(e);
        }
    }

    private static class SingletonHolder {
        private static final FEDict INSTANCE;
        static {
            try {
                INSTANCE = new FEDict(readInput(new InputSupplier<InputStream>() {
                    @Override
                    public InputStream getInput() throws IOException {
                        return getClass().getClassLoader().getResourceAsStream(DEFAULT_FILENAME);
                    }
                }));
            } catch (LoadingException e) {
                throw new RuntimeException(e);
            }
        }
    }

    public FEDict(Map<String, THashSet<String>> frameElementsForFrame) {
        this.frameElementsForFrame = frameElementsForFrame;
    }

    /**
     * Lazy-loading singleton
     */
    public static FEDict getInstance() {
        return SingletonHolder.INSTANCE;
    }

    /**
     * Initialize from a serialized HashMap
     * @param dictFilename the path to the file containing the serialized HashMap
     */
    public static FEDict fromFile(String dictFilename) throws LoadingException {
        return new FEDict(readInput(Files.newInputStreamSupplier(new File(dictFilename))));
    }

    private static Map<String, THashSet<String>> readInput(final InputSupplier<? extends InputStream> inputSupplier)
            throws LoadingException {
        try {
            return SerializedObjects.readObject(new InputSupplier<ObjectInputStream>() {
                @Override
                public ObjectInputStream getInput() throws IOException {
                    return new ObjectInputStream(new BufferedInputStream(inputSupplier.getInput()));
                }
            });
        } catch (Exception e) {
            throw new LoadingException(e);
        }
    }

    /**
     * Get the frame elements for the given frame
     * @param frame the frame to look up
     * @return an array of frame elements of `frame`
     */
    public String[] lookupFrameElements(String frame) {
        THashSet<String> frameElements = frameElementsForFrame.get(frame);
        if (frameElements == null)
            return new String[0];
        return frameElements.toArray(new String[frameElements.size()]);
    }
}