co.cask.cdap.internal.app.runtime.batch.StreamDecoderDetectionTest.java Source code

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Here is the source code for co.cask.cdap.internal.app.runtime.batch.StreamDecoderDetectionTest.java

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/*
 * Copyright  2015-2016 Cask Data, Inc.
 *
 * 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 co.cask.cdap.internal.app.runtime.batch;

import co.cask.cdap.api.flow.flowlet.StreamEvent;
import co.cask.cdap.data.stream.StreamInputFormat;
import co.cask.cdap.data.stream.decoder.IdentityStreamEventDecoder;
import co.cask.cdap.data.stream.decoder.TextStreamEventDecoder;
import com.google.common.reflect.TypeToken;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.io.LongWritable;
import org.apache.hadoop.io.Text;
import org.apache.hadoop.mapreduce.Job;
import org.apache.hadoop.mapreduce.Mapper;
import org.junit.Assert;
import org.junit.Test;

import java.io.IOException;

/**
 * Unit test for stream decoder detection.
 */
public class StreamDecoderDetectionTest {

    @Test
    public void testDecoderDetection() throws IOException {
        Configuration hConf = new Configuration();

        hConf.setClass(Job.MAP_CLASS_ATTR, IdentityMapper.class, Mapper.class);
        StreamInputFormat.inferDecoderClass(hConf,
                MapReduceRuntimeService.getInputValueType(hConf, Void.class, getMapperTypeToken(hConf)));
        Assert.assertSame(IdentityStreamEventDecoder.class, StreamInputFormat.getDecoderClass(hConf));

        hConf.setClass(Job.MAP_CLASS_ATTR, NoTypeMapper.class, Mapper.class);
        StreamInputFormat.inferDecoderClass(hConf,
                MapReduceRuntimeService.getInputValueType(hConf, StreamEvent.class, getMapperTypeToken(hConf)));
        Assert.assertSame(IdentityStreamEventDecoder.class, StreamInputFormat.getDecoderClass(hConf));

        hConf.setClass(Job.MAP_CLASS_ATTR, TextMapper.class, Mapper.class);
        StreamInputFormat.inferDecoderClass(hConf,
                MapReduceRuntimeService.getInputValueType(hConf, Void.class, getMapperTypeToken(hConf)));
        Assert.assertSame(TextStreamEventDecoder.class, StreamInputFormat.getDecoderClass(hConf));

        try {
            hConf.setClass(Job.MAP_CLASS_ATTR, InvalidTypeMapper.class, Mapper.class);
            StreamInputFormat.inferDecoderClass(hConf,
                    MapReduceRuntimeService.getInputValueType(hConf, Void.class, getMapperTypeToken(hConf)));
            Assert.fail("Expected Exception");
        } catch (IllegalArgumentException e) {
            // Expected
        }
    }

    private TypeToken<?> getMapperTypeToken(Configuration hConf) {
        return MapReduceRuntimeService.resolveClass(hConf, Job.MAP_CLASS_ATTR, Mapper.class);
    }

    public static final class IdentityMapper extends Mapper<LongWritable, StreamEvent, String, String> {
        // No-op
    }

    public static final class NoTypeMapper extends Mapper {
        // No-op
    }

    public static final class TextMapper extends Mapper<LongWritable, Text, String, String> {
        // No-op
    }

    public static final class InvalidTypeMapper<I, O> extends Mapper<I, O, String, String> {
        // No-op
    }
}