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package eu.dnetlib.data.mapreduce.hbase.statsExport.eu.dnetlib.data.mapreduce.statsExport.mapreduce;
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import org.apache.hadoop.hbase.io.ImmutableBytesWritable;
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import org.apache.hadoop.io.Text;
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import org.apache.hadoop.mapreduce.Reducer;
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import org.apache.hadoop.mapreduce.TaskInputOutputContext;
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import org.apache.hadoop.mapreduce.lib.output.MultipleOutputs;
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import org.apache.log4j.Logger;
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import java.io.IOException;
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import java.nio.charset.Charset;
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import java.util.Iterator;
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public class StatsReducer extends Reducer<Text, ImmutableBytesWritable, Text, Text> {
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	private Logger log = Logger.getLogger(StatsReducer.class);
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	private MultipleOutputs MultipleOutputWriter;
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	/**
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	 * Reducer that splits input according to their Type ( datasource, results
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	 * etc..) and writes each kind to a seperate output
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	 */
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	@Override
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	protected void setup(Context context) throws IOException, InterruptedException {
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		MultipleOutputWriter = new MultipleOutputs((TaskInputOutputContext) context);
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	};
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	@Override
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	protected void reduce(final Text key, final Iterable<ImmutableBytesWritable> values, final Context context) throws IOException, InterruptedException {
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		Iterator<ImmutableBytesWritable> it = values.iterator();
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		while (it.hasNext()) {
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			String[] split = key.toString().split(",");
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			String type = split[0];
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			String id = split[1];
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			String value = new String(it.next().copyBytes(),Charset.forName("UTF-8"));
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			value = value.trim();
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			MultipleOutputWriter.write(type, new Text(id.getBytes(Charset.forName("UTF-8"))), new Text(value.getBytes(Charset.forName("UTF-8"))), type.toString());
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		}
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	}
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	@Override
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	protected void cleanup(Context context) throws IOException, InterruptedException {
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		log.info("Cleaning up reducer...");
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		MultipleOutputWriter.close();
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	}
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}