co.cask.hydrator.plugin.batch.sink.MongoDBBatchSink.java Source code

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Here is the source code for co.cask.hydrator.plugin.batch.sink.MongoDBBatchSink.java

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/*
 * Copyright  2015 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.hydrator.plugin.batch.sink;

import co.cask.cdap.api.annotation.Description;
import co.cask.cdap.api.annotation.Name;
import co.cask.cdap.api.annotation.Plugin;
import co.cask.cdap.api.data.batch.Output;
import co.cask.cdap.api.data.batch.OutputFormatProvider;
import co.cask.cdap.api.data.format.StructuredRecord;
import co.cask.cdap.api.data.schema.Schema;
import co.cask.cdap.api.dataset.lib.KeyValue;
import co.cask.cdap.etl.api.Emitter;
import co.cask.cdap.etl.api.batch.BatchSink;
import co.cask.cdap.etl.api.batch.BatchSinkContext;
import co.cask.hydrator.common.ReferenceBatchSink;
import co.cask.hydrator.common.ReferencePluginConfig;
import com.mongodb.BasicDBObjectBuilder;
import com.mongodb.hadoop.MongoOutputFormat;
import com.mongodb.hadoop.io.BSONWritable;
import org.apache.hadoop.io.NullWritable;

import java.util.HashMap;
import java.util.Map;

/**
 * A {@link BatchSink} that writes data to MongoDB.
 * This {@link MongoDBBatchSink} takes a {@link StructuredRecord} in,
 * converts it to {@link BSONWritable}, and writes it to MongoDB.
 */
@Plugin(type = "batchsink")
@Name("MongoDB")
@Description("MongoDB Batch Sink converts a StructuredRecord to a BSONWritable and writes it to MongoDB.")
public class MongoDBBatchSink extends ReferenceBatchSink<StructuredRecord, NullWritable, BSONWritable> {

    private final MongoDBSinkConfig config;

    public MongoDBBatchSink(MongoDBSinkConfig config) {
        super(config);
        this.config = config;
    }

    @Override
    public void prepareRun(BatchSinkContext context) throws Exception {
        context.addOutput(Output.of(config.referenceName, new MongoDBOutputFormatProvider(config)));
    }

    @Override
    public void transform(StructuredRecord input, Emitter<KeyValue<NullWritable, BSONWritable>> emitter)
            throws Exception {
        BasicDBObjectBuilder bsonBuilder = BasicDBObjectBuilder.start();
        for (Schema.Field field : input.getSchema().getFields()) {
            bsonBuilder.add(field.getName(), input.get(field.getName()));
        }
        emitter.emit(new KeyValue<>(NullWritable.get(), new BSONWritable(bsonBuilder.get())));
    }

    private static class MongoDBOutputFormatProvider implements OutputFormatProvider {
        private final Map<String, String> conf;

        public MongoDBOutputFormatProvider(MongoDBSinkConfig config) {
            this.conf = new HashMap<>();
            conf.put("mongo.output.uri", config.connectionString);
        }

        @Override
        public String getOutputFormatClassName() {
            return MongoOutputFormat.class.getName();
        }

        @Override
        public Map<String, String> getOutputFormatConfiguration() {
            return conf;
        }
    }

    /**
     * Config class for {@link MongoDBBatchSink}
     */
    public static class MongoDBSinkConfig extends ReferencePluginConfig {
        @Name(Properties.CONNECTION_STRING)
        @Description("MongoDB Connection String (see http://docs.mongodb.org/manual/reference/connection-string); "
                + "Example: 'mongodb://localhost:27017/analytics.users'.")
        private String connectionString;

        public MongoDBSinkConfig(String referenceName, String connectionString) {
            super(referenceName);
            this.connectionString = connectionString;
        }
    }

    /**
     * Property names for config
     */
    public static class Properties {
        public static final String CONNECTION_STRING = "connectionString";
    }
}