org.apache.samza.system.eventhub.descriptors.EventHubsInputDescriptor.java Source code

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Here is the source code for org.apache.samza.system.eventhub.descriptors.EventHubsInputDescriptor.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.samza.system.eventhub.descriptors;

import java.util.HashMap;
import java.util.Map;
import java.util.Optional;
import org.apache.commons.lang3.StringUtils;
import org.apache.samza.config.ConfigException;
import org.apache.samza.system.descriptors.InputDescriptor;
import org.apache.samza.system.descriptors.SystemDescriptor;
import org.apache.samza.serializers.KVSerde;
import org.apache.samza.serializers.NoOpSerde;
import org.apache.samza.serializers.Serde;
import org.apache.samza.system.eventhub.EventHubConfig;

/**
 * A {@link EventHubsInputDescriptor} can be used for specifying Samza and EventHubs-specific properties of EventHubs
 * input streams.
 * <p>
 * Use {@link EventHubsSystemDescriptor#getInputDescriptor} to obtain an instance of this descriptor.
 * <p>
 * Stream properties provided in configuration override corresponding properties specified using a descriptor.
 *
 * @param <StreamMessageType> type of messages in this stream
 */
public class EventHubsInputDescriptor<StreamMessageType>
        extends InputDescriptor<StreamMessageType, EventHubsInputDescriptor<StreamMessageType>> {
    private final String namespace;
    private final String entityPath;
    private Optional<String> sasKeyName = Optional.empty();
    private Optional<String> sasToken = Optional.empty();
    private Optional<String> consumerGroup = Optional.empty();

    /**
     * Constructs an {@link InputDescriptor} instance.
     *
     * @param streamId id of the stream
     * @param namespace namespace for the Event Hubs entity to consume from, not null
     * @param entityPath entity path for the Event Hubs entity to consume from, not null
     * @param valueSerde serde the values in the messages in the stream
     * @param systemDescriptor system descriptor this stream descriptor was obtained from
     */
    EventHubsInputDescriptor(String streamId, String namespace, String entityPath, Serde valueSerde,
            SystemDescriptor systemDescriptor) {
        super(streamId, KVSerde.of(new NoOpSerde<>(), valueSerde), systemDescriptor, null);
        this.namespace = StringUtils.stripToNull(namespace);
        this.entityPath = StringUtils.stripToNull(entityPath);
        if (this.namespace == null || this.entityPath == null) {
            throw new ConfigException(
                    String.format("Missing namespace and entity path Event Hubs input descriptor in " //
                            + "system: {%s}, stream: {%s}", getSystemName(), streamId));
        }
    }

    /**
     * SAS Key name of the associated input stream. Required to access the input Event Hubs entity per stream.
     *
     * @param sasKeyName the name of the SAS key required to access the Event Hubs entity
     * @return this input descriptor
     */
    public EventHubsInputDescriptor<StreamMessageType> withSasKeyName(String sasKeyName) {
        this.sasKeyName = Optional.ofNullable(StringUtils.stripToNull(sasKeyName));
        return this;
    }

    /**
     * SAS Token of the associated input stream. Required to access the input Event Hubs per stream.
     *
     * @param sasToken the SAS token required to access the Event Hubs entity
     * @return this input descriptor
     */
    public EventHubsInputDescriptor<StreamMessageType> withSasKey(String sasToken) {
        this.sasToken = Optional.ofNullable(StringUtils.stripToNull(sasToken));
        return this;
    }

    /**
     * Set the consumer group from the upstream Event Hubs entity that the consumer is part of. Defaults to the
     * <code>$Default</code> group that is initially present in all Event Hubs entities (unless removed)
     *
     * @param consumerGroup the name of the consumer group upstream
     * @return this input descriptor
     */
    public EventHubsInputDescriptor<StreamMessageType> withConsumerGroup(String consumerGroup) {
        this.consumerGroup = Optional.ofNullable(StringUtils.stripToNull(consumerGroup));
        return this;
    }

    @Override
    public Map<String, String> toConfig() {
        Map<String, String> ehConfigs = new HashMap<>(super.toConfig());

        String streamId = getStreamId();

        ehConfigs.put(String.format(EventHubConfig.CONFIG_STREAM_NAMESPACE, streamId), namespace);
        ehConfigs.put(String.format(EventHubConfig.CONFIG_STREAM_ENTITYPATH, streamId), entityPath);

        sasKeyName.ifPresent(keyName -> ehConfigs
                .put(String.format(EventHubConfig.CONFIG_STREAM_SAS_KEY_NAME, streamId), keyName));
        sasToken.ifPresent(
                key -> ehConfigs.put(String.format(EventHubConfig.CONFIG_STREAM_SAS_TOKEN, streamId), key));
        consumerGroup.ifPresent(consumerGroupName -> ehConfigs
                .put(String.format(EventHubConfig.CONFIG_STREAM_CONSUMER_GROUP, streamId), consumerGroupName));
        return ehConfigs;
    }

}