org.apache.gora.mapreduce.GoraMapper.java Source code

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Here is the source code for org.apache.gora.mapreduce.GoraMapper.java

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/**
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you 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 org.apache.gora.mapreduce;

import java.io.IOException;

import org.apache.gora.persistency.Persistent;
import org.apache.gora.query.Query;
import org.apache.gora.store.DataStore;
import org.apache.hadoop.mapreduce.Job;
import org.apache.hadoop.mapreduce.Mapper;
import org.apache.hadoop.mapreduce.Partitioner;

/**
 * Base class for Gora based {@link Mapper}s.
 */
public class GoraMapper<K1, V1 extends Persistent, K2, V2> extends Mapper<K1, V1, K2, V2> {

    /**
     * Initializes the Mapper, and sets input parameters for the job. All of 
     * the records in the dataStore are used as the input. If you want to 
     * include a specific subset, use one of the overloaded methods which takes
     * query parameter.
     * @param job the job to set the properties for
     * @param dataStoreClass the datastore class
     * @param inKeyClass Map input key class
     * @param inValueClass Map input value class
     * @param outKeyClass Map output key class
     * @param outValueClass Map output value class
     * @param mapperClass the mapper class extending GoraMapper
     * @param partitionerClass optional partitioner class
     * @param reuseObjects whether to reuse objects in serialization
     */
    @SuppressWarnings("rawtypes")
    public static <K1, V1 extends Persistent, K2, V2> void initMapperJob(Job job,
            Class<? extends DataStore<K1, V1>> dataStoreClass, Class<K1> inKeyClass, Class<V1> inValueClass,
            Class<K2> outKeyClass, Class<V2> outValueClass, Class<? extends GoraMapper> mapperClass,
            Class<? extends Partitioner> partitionerClass, boolean reuseObjects) throws IOException {

        //set the input via GoraInputFormat
        GoraInputFormat.setInput(job, dataStoreClass, inKeyClass, inValueClass, reuseObjects);

        job.setMapperClass(mapperClass);
        job.setMapOutputKeyClass(outKeyClass);
        job.setMapOutputValueClass(outValueClass);

        if (partitionerClass != null) {
            job.setPartitionerClass(partitionerClass);
        }
    }

    /**
     * Initializes the Mapper, and sets input parameters for the job. All of 
     * the records in the dataStore are used as the input. If you want to 
     * include a specific subset, use one of the overloaded methods which takes
     * query parameter.
     * @param job the job to set the properties for
     * @param dataStoreClass the datastore class
     * @param inKeyClass Map input key class
     * @param inValueClass Map input value class
     * @param outKeyClass Map output key class
     * @param outValueClass Map output value class
     * @param mapperClass the mapper class extending GoraMapper
     * @param reuseObjects whether to reuse objects in serialization
     */
    @SuppressWarnings("rawtypes")
    public static <K1, V1 extends Persistent, K2, V2> void initMapperJob(Job job,
            Class<? extends DataStore<K1, V1>> dataStoreClass, Class<K1> inKeyClass, Class<V1> inValueClass,
            Class<K2> outKeyClass, Class<V2> outValueClass, Class<? extends GoraMapper> mapperClass,
            boolean reuseObjects) throws IOException {
        initMapperJob(job, dataStoreClass, inKeyClass, inValueClass, outKeyClass, outValueClass, mapperClass, null,
                reuseObjects);
    }

    /**
     * Initializes the Mapper, and sets input parameters for the job
     * @param job the job to set the properties for
     * @param query the query to get the inputs from
     * @param dataStore the datastore as the input
     * @param outKeyClass Map output key class
     * @param outValueClass Map output value class
     * @param mapperClass the mapper class extending GoraMapper
     * @param partitionerClass optional partitioner class
     * @param reuseObjects whether to reuse objects in serialization
     */
    @SuppressWarnings("rawtypes")
    public static <K1, V1 extends Persistent, K2, V2> void initMapperJob(Job job, Query<K1, V1> query,
            DataStore<K1, V1> dataStore, Class<K2> outKeyClass, Class<V2> outValueClass,
            Class<? extends GoraMapper> mapperClass, Class<? extends Partitioner> partitionerClass,
            boolean reuseObjects) throws IOException {
        //set the input via GoraInputFormat
        GoraInputFormat.setInput(job, query, dataStore, reuseObjects);

        job.setMapperClass(mapperClass);
        job.setMapOutputKeyClass(outKeyClass);
        job.setMapOutputValueClass(outValueClass);

        if (partitionerClass != null) {
            job.setPartitionerClass(partitionerClass);
        }
    }

    /**
     * Initializes the Mapper, and sets input parameters for the job
     * @param job the job to set the properties for
     * @param dataStore the datastore as the input
     * @param outKeyClass Map output key class
     * @param outValueClass Map output value class
     * @param mapperClass the mapper class extending GoraMapper
     * @param reuseObjects whether to reuse objects in serialization
     */
    @SuppressWarnings({ "rawtypes" })
    public static <K1, V1 extends Persistent, K2, V2> void initMapperJob(Job job, DataStore<K1, V1> dataStore,
            Class<K2> outKeyClass, Class<V2> outValueClass, Class<? extends GoraMapper> mapperClass,
            boolean reuseObjects) throws IOException {
        initMapperJob(job, dataStore.newQuery(), dataStore, outKeyClass, outValueClass, mapperClass, reuseObjects);
    }

    /**
     * Initializes the Mapper, and sets input parameters for the job
     * @param job the job to set the properties for
     * @param query the query to get the inputs from
     * @param dataStore the datastore as the input
     * @param outKeyClass Map output key class
     * @param outValueClass Map output value class
     * @param mapperClass the mapper class extending GoraMapper
     * @param reuseObjects whether to reuse objects in serialization
     */
    @SuppressWarnings({ "rawtypes" })
    public static <K1, V1 extends Persistent, K2, V2> void initMapperJob(Job job, Query<K1, V1> query,
            DataStore<K1, V1> dataStore, Class<K2> outKeyClass, Class<V2> outValueClass,
            Class<? extends GoraMapper> mapperClass, boolean reuseObjects) throws IOException {
        initMapperJob(job, query, dataStore, outKeyClass, outValueClass, mapperClass, null, reuseObjects);
    }
}