Java tutorial
/* * 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.kinesis.descriptors; import java.util.Collections; import java.util.HashMap; import java.util.Map; import java.util.Optional; import org.apache.commons.lang3.StringUtils; import org.apache.samza.operators.KV; import org.apache.samza.serializers.Serde; import org.apache.samza.system.descriptors.SystemDescriptor; import org.apache.samza.system.kinesis.KinesisConfig; import org.apache.samza.system.kinesis.KinesisSystemFactory; /** * A {@link KinesisSystemDescriptor} can be used for specifying Samza and Kinesis-specific properties of a Kinesis * input system. It can also be used for obtaining {@link KinesisInputDescriptor}s, * which can be used for specifying Samza and system-specific properties of Kinesis input streams. * <p> * System properties provided in configuration override corresponding properties specified using a descriptor. */ public class KinesisSystemDescriptor extends SystemDescriptor<KinesisSystemDescriptor> { private static final String FACTORY_CLASS_NAME = KinesisSystemFactory.class.getName(); private Optional<String> region = Optional.empty(); private Optional<String> proxyHost = Optional.empty(); private Optional<Integer> proxyPort = Optional.empty(); private Map<String, String> awsConfig = Collections.emptyMap(); private Map<String, String> kclConfig = Collections.emptyMap(); public KinesisSystemDescriptor(String systemName) { super(systemName, FACTORY_CLASS_NAME, null, null); } /** * Gets an {@link KinesisInputDescriptor} for the input stream of this system. * <p> * The message in the stream will have {@link String} keys and {@code ValueType} values. * * @param streamId id of the input stream * @param valueSerde stream level serde for the values in the messages in the input stream * @param <ValueType> type of the value in the messages in this stream * @return an {@link KinesisInputDescriptor} for the Kinesis input stream */ public <ValueType> KinesisInputDescriptor<KV<String, ValueType>> getInputDescriptor(String streamId, Serde<ValueType> valueSerde) { return new KinesisInputDescriptor<>(streamId, valueSerde, this); } /** * Kinesis region for this system. * @param region Kinesis region * @return this system descriptor */ public KinesisSystemDescriptor withRegion(String region) { this.region = Optional.ofNullable(StringUtils.stripToNull(region)); return this; } /** * AWS config for this system. This is not required by default. * @param awsConfig A map of specified AWS configs * @return this system descriptor */ public KinesisSystemDescriptor withAWSConfig(Map<String, String> awsConfig) { this.awsConfig = awsConfig; return this; } /** * KCL (Kinesis Client Library) config for this system. This is not required by default. * @param kclConfig A map of specified KCL configs * @return this system descriptor */ public KinesisSystemDescriptor withKCLConfig(Map<String, String> kclConfig) { this.kclConfig = kclConfig; return this; } /** * Proxy host to be used for this system. * @param proxyHost Proxy host * @return this system descriptor */ public KinesisSystemDescriptor withProxyHost(String proxyHost) { this.proxyHost = Optional.ofNullable(StringUtils.stripToNull(proxyHost)); return this; } /** * Proxy port to be used for this system. * @param proxyPort Proxy port * @return this system descriptor */ public KinesisSystemDescriptor withProxyPort(int proxyPort) { this.proxyPort = Optional.of(proxyPort); return this; } @Override public Map<String, String> toConfig() { Map<String, String> config = new HashMap<>(super.toConfig()); String systemName = getSystemName(); region.ifPresent(val -> config.put(String.format(KinesisConfig.CONFIG_SYSTEM_REGION, systemName), val)); proxyHost.ifPresent(val -> config.put(String.format(KinesisConfig.CONFIG_PROXY_HOST, systemName), val)); proxyPort.ifPresent( val -> config.put(String.format(KinesisConfig.CONFIG_PROXY_PORT, systemName), String.valueOf(val))); String kclConfigPrefix = String.format(KinesisConfig.CONFIG_SYSTEM_KINESIS_CLIENT_LIB_CONFIG, systemName); kclConfig.forEach((k, v) -> config.put(kclConfigPrefix + k, v)); String awsConfigPrefix = String.format(KinesisConfig.CONFIG_AWS_CLIENT_CONFIG, systemName); awsConfig.forEach((k, v) -> config.put(awsConfigPrefix + k, v)); return config; } }