001/** 
002 * Copyright (c) 2012, Regents of the University of Colorado 
003 * All rights reserved.
004 * 
005 * Redistribution and use in source and binary forms, with or without
006 * modification, are permitted provided that the following conditions are met:
007 * 
008 * Redistributions of source code must retain the above copyright notice, this list of conditions and the following disclaimer. 
009 * Redistributions in binary form must reproduce the above copyright notice, this list of conditions and the following disclaimer in the documentation and/or other materials provided with the distribution. 
010 * Neither the name of the University of Colorado at Boulder nor the names of its contributors may be used to endorse or promote products derived from this software without specific prior written permission. 
011 * 
012 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
013 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
014 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
015 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
016 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
017 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
018 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
019 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
020 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
021 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
022 * POSSIBILITY OF SUCH DAMAGE. 
023 */
024
025package org.cleartk.ml.feature.transform;
026
027import java.io.BufferedOutputStream;
028import java.io.File;
029import java.io.FileOutputStream;
030import java.io.IOException;
031import java.io.ObjectOutputStream;
032
033import org.cleartk.ml.CleartkProcessingException;
034import org.cleartk.ml.DataWriter;
035import org.cleartk.ml.Instance;
036
037/**
038 * 
039 * <br>
040 * Copyright (c) 2011-2012, Regents of the University of Colorado <br>
041 * All rights reserved.
042 * 
043 * This training data (instance) consumer produces intermediate storage of instances for later use
044 * in feature transformation (i.e. normalization, clustering, etc...)
045 * 
046 * @author Lee Becker
047 * 
048 * @param <OUTCOME_T>
049 *          - The outcome type of the instances it writes out
050 */
051public class InstanceDataWriter<OUTCOME_T> implements DataWriter<OUTCOME_T> {
052
053  ObjectOutputStream objout;
054
055  public static String INSTANCES_OUTPUT_FILENAME = "training-data.instances";
056
057  public InstanceDataWriter(File outputDirectory) throws IOException {
058    if (!outputDirectory.exists()) {
059      outputDirectory.mkdirs();
060    }
061
062    // Initialize Object Serializer
063    File outputFile = new File(outputDirectory, INSTANCES_OUTPUT_FILENAME);
064    this.objout = new ObjectOutputStream(new BufferedOutputStream(new FileOutputStream(outputFile)));
065  }
066
067  @Override
068  public void write(Instance<OUTCOME_T> instance) throws CleartkProcessingException {
069    try {
070      this.objout.writeObject(instance);
071    } catch (IOException e) {
072      throw new CleartkProcessingException("", "Unable to write Instance", e);
073    }
074  }
075
076  @Override
077  public void finish() throws CleartkProcessingException {
078    try {
079      // We need to add a "null" instance terminator to gracefully handle the iteration while
080      // reading in serialized objects from file
081      InstanceStream.Terminator<OUTCOME_T> terminator = new InstanceStream.Terminator<OUTCOME_T>();
082      this.objout.writeObject(terminator);
083
084      this.objout.close();
085    } catch (IOException e) {
086      throw new CleartkProcessingException("", "Unable to write terminal instance", e);
087    }
088
089  }
090
091}