com.ottogroup.bi.streaming.sink.kafka.KafkaProducerBuilder.java Source code

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Here is the source code for com.ottogroup.bi.streaming.sink.kafka.KafkaProducerBuilder.java

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/**
 * Copyright 2016 Otto (GmbH & Co KG)
 *
 * 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 com.ottogroup.bi.streaming.sink.kafka;

import java.io.Serializable;
import java.util.Properties;

import org.apache.commons.lang3.StringUtils;
import org.apache.flink.streaming.connectors.kafka.FlinkKafkaProducer09;
import org.apache.flink.streaming.util.serialization.SerializationSchema;
import org.apache.kafka.clients.producer.ProducerConfig;

import com.ottogroup.bi.streaming.source.kafka.KafkaConsumerBuilder;

/**
 * Provides support for creating {@link FlinkKafkaProducer08} instances
 * @author mnxfst
 * @since Feb 29, 2016
 */
public class KafkaProducerBuilder<T extends Serializable> implements Serializable {

    private static final long serialVersionUID = 878130140393093604L;

    private Properties properties = new Properties();
    private String topic;
    private String brokerList;
    private SerializationSchema<T> serializationSchema;

    private KafkaProducerBuilder() {
    }

    /**
     * Returns a new {@link KafkaConsumerBuilder} instance
     * @return
     */
    public static <T extends Serializable> KafkaProducerBuilder<T> getInstance() {
        return new KafkaProducerBuilder<T>();
    }

    /**
     * Sets the topic to produce data to
     * @param topic
     * @return
     */
    public KafkaProducerBuilder<T> topic(final String topic) {
        if (StringUtils.isNotBlank(topic))
            this.topic = topic;
        return this;
    }

    /**
     * Sets the broker list to produce data to
     * @param topic
     * @return
     */
    public KafkaProducerBuilder<T> brokerList(final String brokerList) {
        if (StringUtils.isNotBlank(brokerList))
            this.brokerList = brokerList;
        return this;
    }

    /**
     * Adds a new key/value pair to properties
     * @param key
     * @param value
     * @return
     */
    public KafkaProducerBuilder<T> addProperty(final String key, final String value) {
        if (StringUtils.isNotBlank(key) && value != null)
            this.properties.put(StringUtils.lowerCase(StringUtils.trim(key)), value);
        return this;
    }

    /**
     * Adds all key/value pairs to properties
     * @param properties
     * @return
     */
    public KafkaProducerBuilder<T> addProperties(final Properties properties) {
        if (properties != null && !properties.isEmpty())
            this.properties.putAll(properties);
        return this;
    }

    /**
     * Sets the {@link SerializationSchema} required for writing data to kafka topic 
     * @param serializationSchema
     * @return
     */
    public KafkaProducerBuilder<T> serializationSchema(final SerializationSchema<T> serializationSchema) {
        if (serializationSchema != null)
            this.serializationSchema = serializationSchema;
        return this;
    }

    /**
     * Create a {@link FlinkKafkaProducer09} depending on the provided settings
     * @param version
     * @return
     */
    public FlinkKafkaProducer09<T> create() {

        /////////////////////////////////////////////////////////////////////////
        // validate provided input
        if (StringUtils.isBlank(this.topic))
            throw new IllegalArgumentException("Missing required topic");
        if (StringUtils.isBlank(this.brokerList))
            throw new IllegalArgumentException("Missing required broker list");
        /////////////////////////////////////////////////////////////////////////

        if (!this.properties.isEmpty()) {
            Properties producerProperties = new Properties();
            producerProperties.put(ProducerConfig.BOOTSTRAP_SERVERS_CONFIG, this.brokerList);

            for (Object k : this.properties.keySet())
                producerProperties.put(k, this.properties.get(k));
            return new FlinkKafkaProducer09<>(this.topic, this.serializationSchema, producerProperties);
        }
        return new FlinkKafkaProducer09<T>(this.brokerList, this.topic, this.serializationSchema);
    }

    /**
     * Returns the broker list - implemented for testing purpose only 
     * @return
     */
    protected String getBrokerList() {
        return this.brokerList;
    }

    /**
     * Returns the managed topic - implemented for testing purpose only 
     * @return
     */
    protected String getTopic() {
        return this.topic;
    }

    /**
     * Returns the managed topic - implemented for testing purpose only 
     * @return
     */
    protected Properties getProperties() {
        return this.properties;
    }

}