com.conversantmedia.mapreduce.tool.annotation.handler.ReducerInfoHandler.java Source code

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Here is the source code for com.conversantmedia.mapreduce.tool.annotation.handler.ReducerInfoHandler.java

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package com.conversantmedia.mapreduce.tool.annotation.handler;

/*
 * #%L
 * Mara Core framework
 * ~~
 * Copyright (C) 2015 Conversant
 * ~~
 * 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.
 * #L%
 */

import java.lang.annotation.Annotation;
import java.lang.reflect.Type;

import org.apache.hadoop.mapreduce.Job;
import org.apache.hadoop.mapreduce.Reducer;
import org.springframework.stereotype.Service;

import com.conversantmedia.mapreduce.tool.annotation.ReducerInfo;

/**
 *
 *
 */
@Service
public class ReducerInfoHandler extends AnnotationHandlerBase {

    @Override
    public boolean accept(Annotation annotation) {
        return annotation.annotationType() == ReducerInfo.class;
    }

    @Override
    @SuppressWarnings({ "rawtypes" })
    public void process(Annotation annotation, Job job, Object target) {
        ReducerInfo reduce = (ReducerInfo) annotation;
        if (reduce != null && reduce.value() != org.apache.hadoop.mapreduce.Reducer.class) {
            Class<? extends Reducer> reducerClass = reduce.value();
            job.setReducerClass(reducerClass);
            // shouldn't use defaults, but there so that we can keep the option to
            // set as a property of the JobInfo annotation instead of standalone
            configureOutputKeyValue(job, reducerClass, reduce);
        }
    }

    @SuppressWarnings("rawtypes")
    protected void configureOutputKeyValue(Job job, Class<? extends Reducer> reducerClass, ReducerInfo reducer) {
        MaraAnnotationUtil util = MaraAnnotationUtil.INSTANCE;
        // Try and work it out from the generics
        Type[] params = util.getGenericTypeParams(reducerClass, Reducer.class);

        if (reducer != null && reducer.output().key() != void.class) {
            job.setOutputKeyClass(reducer.output().key());
        } else if (params != null && params.length == 4) {
            job.setOutputKeyClass((Class<?>) params[2]);
        }

        if (reducer != null && reducer.output().value() != void.class) {
            job.setOutputValueClass(reducer.output().value());
        } else if (params != null && params.length == 4) {
            job.setOutputValueClass((Class<?>) params[3]);
        }
    }
}