001/**
002 * Copyright (c) 2011, The University of Southampton and the individual contributors.
003 * All rights reserved.
004 *
005 * Redistribution and use in source and binary forms, with or without modification,
006 * are permitted provided that the following conditions are met:
007 *
008 *   *  Redistributions of source code must retain the above copyright notice,
009 *      this list of conditions and the following disclaimer.
010 *
011 *   *  Redistributions in binary form must reproduce the above copyright notice,
012 *      this list of conditions and the following disclaimer in the documentation
013 *      and/or other materials provided with the distribution.
014 *
015 *   *  Neither the name of the University of Southampton nor the names of its
016 *      contributors may be used to endorse or promote products derived from this
017 *      software without specific prior written permission.
018 *
019 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
020 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
021 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
022 * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR
023 * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
024 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
025 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
026 * ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
027 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
028 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
029 */
030package org.openimaj.hadoop.tools.twitter;
031
032import java.io.IOException;
033import java.io.PrintWriter;
034import java.io.StringWriter;
035import java.util.List;
036
037import org.apache.hadoop.io.LongWritable;
038import org.apache.hadoop.io.NullWritable;
039import org.apache.hadoop.io.Text;
040import org.apache.hadoop.mapreduce.Mapper;
041import org.kohsuke.args4j.CmdLineException;
042import org.openimaj.tools.twitter.modes.preprocessing.TwitterPreprocessingMode;
043import org.openimaj.tools.twitter.options.AbstractTwitterPreprocessingToolOptions;
044import org.openimaj.twitter.GeneralJSONTwitter;
045import org.openimaj.twitter.USMFStatus;
046
047/**
048 * This mapper loads arguments for the
049 * {@link AbstractTwitterPreprocessingToolOptions} from the
050 * {@link HadoopTwitterPreprocessingTool#ARGS_KEY} variable (once per in memory
051 * mapper) and uses these to preprocess tweets.
052 * 
053 * @author Sina Samangooei (ss@ecs.soton.ac.uk)
054 *
055 */
056public class TwitterPreprocessingMapper extends Mapper<LongWritable, Text, NullWritable, Text> {
057        private static HadoopTwitterPreprocessingToolOptions options = null;
058        private static List<TwitterPreprocessingMode<?>> modes = null;
059
060        protected static synchronized void loadOptions(Mapper<LongWritable, Text, NullWritable, Text>.Context context)
061                        throws IOException
062        {
063                if (options == null) {
064                        try {
065                                options = new HadoopTwitterPreprocessingToolOptions(context.getConfiguration().getStrings(
066                                                HadoopTwitterPreprocessingTool.ARGS_KEY));
067                                options.prepare();
068                                modes = options.preprocessingMode();
069                        } catch (final CmdLineException e) {
070                                throw new IOException(e);
071                        } catch (final Exception e) {
072                                throw new IOException(e);
073                        }
074                }
075        }
076
077        @Override
078        protected void setup(Mapper<LongWritable, Text, NullWritable, Text>.Context context) throws IOException,
079                        InterruptedException
080        {
081                loadOptions(context);
082        }
083
084        @Override
085        protected void map(LongWritable key, Text value, Mapper<LongWritable, Text, NullWritable, Text>.Context context)
086                        throws java.io.IOException, InterruptedException
087        {
088                final USMFStatus status = new USMFStatus(GeneralJSONTwitter.class);
089                status.fillFromString(value.toString());
090                if (status.isInvalid())
091                        return;
092                for (final TwitterPreprocessingMode<?> mode : modes) {
093                        mode.process(status);
094                }
095                final StringWriter outTweetString = new StringWriter();
096                final PrintWriter outTweetWriter = new PrintWriter(outTweetString);
097                try {
098                        options.ouputMode().output(options.convertToOutputFormat(status), outTweetWriter);
099                        context.write(NullWritable.get(), new Text(outTweetString.getBuffer().toString()));
100                } catch (final Exception e) {
101                        System.err.println("Failed to write tweet: " + status.text);
102                        System.err.println("With error: ");
103                        e.printStackTrace();
104                }
105        }
106}