eu.stratosphere.hadoopcompatibility.datatypes.DefaultStratosphereTypeConverter.java Source code

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Here is the source code for eu.stratosphere.hadoopcompatibility.datatypes.DefaultStratosphereTypeConverter.java

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/***********************************************************************************************************************
 * Copyright (C) 2010-2013 by the Stratosphere project (http://stratosphere.eu)
 *
 * 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 eu.stratosphere.hadoopcompatibility.datatypes;

import org.apache.hadoop.io.BooleanWritable;
import org.apache.hadoop.io.ByteWritable;
import org.apache.hadoop.io.DoubleWritable;
import org.apache.hadoop.io.FloatWritable;
import org.apache.hadoop.io.IntWritable;
import org.apache.hadoop.io.LongWritable;
import org.apache.hadoop.io.Text;

import eu.stratosphere.types.BooleanValue;
import eu.stratosphere.types.ByteValue;
import eu.stratosphere.types.DoubleValue;
import eu.stratosphere.types.FloatValue;
import eu.stratosphere.types.IntValue;
import eu.stratosphere.types.LongValue;
import eu.stratosphere.types.Record;
import eu.stratosphere.types.StringValue;

/**
 * Converter Stratosphere Record into the default hadoop writables.
 *
 */
public class DefaultStratosphereTypeConverter<K, V> implements StratosphereTypeConverter<K, V> {
    private static final long serialVersionUID = 1L;

    private Class<K> keyClass;
    private Class<V> valueClass;

    public DefaultStratosphereTypeConverter(Class<K> keyClass, Class<V> valueClass) {
        this.keyClass = keyClass;
        this.valueClass = valueClass;
    }

    @Override
    public K convertKey(Record stratosphereRecord) {
        if (stratosphereRecord.getNumFields() > 0) {
            return convert(stratosphereRecord, 0, this.keyClass);
        } else {
            return null;
        }
    }

    @Override
    public V convertValue(Record stratosphereRecord) {
        if (stratosphereRecord.getNumFields() > 1) {
            return convert(stratosphereRecord, 1, this.valueClass);
        } else {
            return null;
        }
    }

    @SuppressWarnings("unchecked")
    private <T> T convert(Record stratosphereType, int pos, Class<T> hadoopType) {
        if (hadoopType == LongWritable.class) {
            return (T) new LongWritable((stratosphereType.getField(pos, LongValue.class)).getValue());
        }
        if (hadoopType == org.apache.hadoop.io.Text.class) {
            return (T) new Text((stratosphereType.getField(pos, StringValue.class)).getValue());
        }
        if (hadoopType == org.apache.hadoop.io.IntWritable.class) {
            return (T) new IntWritable((stratosphereType.getField(pos, IntValue.class)).getValue());
        }
        if (hadoopType == org.apache.hadoop.io.FloatWritable.class) {
            return (T) new FloatWritable((stratosphereType.getField(pos, FloatValue.class)).getValue());
        }
        if (hadoopType == org.apache.hadoop.io.DoubleWritable.class) {
            return (T) new DoubleWritable((stratosphereType.getField(pos, DoubleValue.class)).getValue());
        }
        if (hadoopType == org.apache.hadoop.io.BooleanWritable.class) {
            return (T) new BooleanWritable((stratosphereType.getField(pos, BooleanValue.class)).getValue());
        }
        if (hadoopType == org.apache.hadoop.io.ByteWritable.class) {
            return (T) new ByteWritable((stratosphereType.getField(pos, ByteValue.class)).getValue());
        }

        throw new RuntimeException("Unable to convert Stratosphere type ("
                + stratosphereType.getClass().getCanonicalName() + ") to Hadoop.");
    }
}