Spark整合kafka0.10.0新特性(一)

子曰："温故而知新，可以为师矣。"学完长时间不使用不复习便会逐渐忘记，故做一下笔记！

Spark Streaming + Kafka Integration Guide (Kafka broker version 0.10.0 or higher)整合kafka0.10.0新特性（API都在实验中）。

 The Spark Streaming integration for Kafka 0.10和kafka0.8的Direct Stream approach非常相似，并行度Kafka分区和Spark分区的比例1:1，并且可以访问Kafka的偏移和元数据。然而，新的整合方案使用的是new Kafka consumer API 而不是 simple API，所以在使用过程中需要注意区别，这个版本的整合现在正处于experimental，因此API可能随着时间会有变化。

Linking

For Scala/Java applications using SBT/Maven project definitions, link your streaming application with the following artifact (see Linkingsectionin the main programming guide for further information).

groupId = org.apache.spark
artifactId = spark-streaming-kafka-0-10_2.11
version = 2.1.0

无论使用sbt还是maven，都需引入上面的坐标。

Creating a Direct Stream

注意导入包的路径是org.apache.spark.streaming.kafka010，切勿倒错包。

import org.apache.kafka.clients.consumer.ConsumerRecord
import org.apache.kafka.common.serialization.StringDeserializer
import org.apache.spark.streaming.kafka010._
import org.apache.spark.streaming.kafka010.LocationStrategies.PreferConsistent
import org.apache.spark.streaming.kafka010.ConsumerStrategies.Subscribe

val kafkaParams = Map[String, Object](
"bootstrap.servers" -> "localhost:9092,anotherhost:9092",
"key.deserializer" -> classOf[StringDeserializer],
"value.deserializer" -> classOf[StringDeserializer],
"group.id" -> "use_a_separate_group_id_for_each_stream",
"auto.offset.reset" -> "latest",
"enable.auto.commit" -> (false: java.lang.Boolean)
)

val topics = Array("topicA", "topicB")
val stream = KafkaUtils.createDirectStream[String, String](
streamingContext,//create entry point for all streaming functionality
PreferConsistent,//important feature：preferConsistent是一个方法，是consumer调度分区的位置策略
  Subscribe[String, String](topics, kafkaParams)//is also import feature ：Subscribe是consumer的消费策略
)

stream.map(record => (record.key, record.value))

重点解释一下 PreferConsistent方法，首先我们还是看一下PreferConsistent方法实现，源码如下：

package org.apache.spark.streaming.kafka010

import java.{util => ju}

import scala.collection.JavaConverters._
import org.apache.kafka.common.TopicPartition
import org.apache.spark.annotation.Experimental
import org.apache.spark.streaming.kafka010.{LocationStrategies, LocationStrategy, PreferFixed}

/**
*  :: Experimental ::
* Choice of how to schedule consumers for a given TopicPartition on an executor.
* See [[LocationStrategies]] to obtain instances.
* Kafka 0.10 consumers prefetch messages, so it's important for performance
* to keep cached consumers on appropriate executors, not recreate them for every partition.
* Choice of location is only a preference, not an absolute; partitions may be scheduled elsewhere.
* 实验性API:
* 在executor上consumer如何调度给定的TopicPartition，使用LocationStrategies获取调度策略实例
* Kafka 0.10的消费者可以预取消息，因此对于性能来说在适合的executors上缓存consumers是比较重要的，而不是对每一个分区
* 进行重新创建。对于分区位置的选择只是一个偏好，并非是绝对的。分区可能被调度到其他位置
*
*
*/
@Experimental
sealed abstract class LocationStrategy

/**
* 使用PreferBrokers策略，必须是你的executors和kafka brokers在相同节点上。
*/
private case object PreferBrokers extends LocationStrategy

/**
* 大多数情况下使用PreferConsistent需要一贯的将kafka的分区分布到所有的executors上
*/
private case object PreferConsistent extends LocationStrategy

/**
* Use this to place particular TopicPartitions on particular hosts if your load is uneven.
* Any TopicPartition not specified in the map will use a consistent location.
* 默认情况如果分区加载的不均衡的话，可以使用这个策略：放置特定的分区到特定的主机上
* 任何TopicPartition没有和hosts映射的TopicPartition将会使用consistent location（就是安置到所有executor）
*
* 参数Map：就是TopicPartition和主机地址的映射
*/
private case class PreferFixed(hostMap: ju.Map[TopicPartition, String]) extends LocationStrategy

/**
* :: Experimental :: object to obtain instances of [[LocationStrategy]]
*
*/
@Experimental
object LocationStrategies {
/**
*  :: Experimental ::
* Use this only if your executors are on the same nodes as your Kafka brokers.
*/
@Experimental
def PreferBrokers: LocationStrategy =
org.apache.spark.streaming.kafka010.PreferBrokers

/**
*  :: Experimental ::
* Use this in most cases, it will consistently distribute partitions across all executors.
*/
@Experimental
def PreferConsistent: LocationStrategy =
org.apache.spark.streaming.kafka010.PreferConsistent

/**
*  :: Experimental ::
* Use this to place particular TopicPartitions on particular hosts if your load is uneven.
* Any TopicPartition not specified in the map will use a consistent location.
* 两个方法就是Map类型不一样而已，一个是Scala Map 另一个是Java Map
*
*/
@Experimental
def PreferFixed(hostMap: collection.Map[TopicPartition, String]): LocationStrategy =
new PreferFixed(new ju.HashMap[TopicPartition, String](hostMap.asJava))

/**
*  :: Experimental ::
* Use this to place particular TopicPartitions on particular hosts if your load is uneven.
* Any TopicPartition not specified in the map will use a consistent location.
*/
@Experimental
def PreferFixed(hostMap: ju.Map[TopicPartition, String]): LocationStrategy =
new PreferFixed(hostMap)
}

接下来学习一下Subscribe，上面Subscribe是伴生对象ConsumerStrategies的一个静态方法，ConsumerStrategies可以说是consumer消费策略的一个工厂。

接下来看一下 ConsumerStrategy，重点部门见源码注释， 源码如下：

package org.apache.spark.streaming.kafka010import java.{ lang => jl, util => ju }import scala.collection.JavaConverters._import org.apache.kafka.clients.consumer._import org.apache.kafka.clients.consumer.internals.NoOpConsumerRebalanceListenerimport org.apache.kafka.common.TopicPartitionimport org.apache.spark.annotation.Experimentalimport org.apache.spark.internal.Logging/*** :: Experimental ::* Choice of how to create and configure underlying Kafka Consumers on driver and executors.* See [[ConsumerStrategies]] to obtain instances.* Kafka 0.10 consumers can require additional, sometimes complex, setup after object*  instantiation. This interface encapsulates that process, and allows it to be checkpointed.* @tparam K type of Kafka message key* @tparam V type of Kafka message value** 选择如何创建和配置在Driver和Executor上的Kafka Consumer实例，使用ConsumerStrategies获取策略实例* Kafka 0.10 consumers 在对象被实例化之后需要额外的配置，有时候比较复杂，这个接口封装了那些过程* 并允许实例被checkpointed**/@Experimentalabstract class ConsumerStrategy[K, V] {/*** Kafka <a href="http://kafka.apache.org/documentation.html#newconsumerconfigs">* configuration parameters</a> to be used on executors. Requires "bootstrap.servers" to be set* with Kafka broker(s) specified in host1:port1,host2:port2 form.*配置参数会在executors上被使用，需要设置bootstrap.servers指定Kafka的broker的主机和端口**/def executorKafkaParams: ju.Map[String, Object]/*** Must return a fully configured Kafka Consumer, including subscribed or assigned topics.* See <a href="http://kafka.apache.org/documentation.html#newconsumerapi">Kafka docs</a>.* This consumer will be used on the driver to query for offsets only, not messages.* The consumer must be returned in a state that it is safe to call poll(0) on.* @param currentOffsets A map from TopicPartition to offset, indicating how far the driver* has successfully read.  Will be empty on initial start, possibly non-empty on restart from* checkpoint.*返回一个必须是fully配置的Kafka Consumer，消费策略可以是subscribed或者assigned* consumer将会在driver上使用查询偏移而不是查询消息* 返回的consumer状态必须是安全的调用poll(0)方法* currentOffsets参数是一个TopicPartition到offset的映射map，可以标示：* driver已经成功读取多少信息，第一次启动时候可能是empty，在checkpoint中restart不为空**/def onStart(currentOffsets: ju.Map[TopicPartition, jl.Long]): Consumer[K, V]}/*** Subscribe to a collection of topics.* @param topics collection of topics to subscribe* @param kafkaParams Kafka* <a href="http://kafka.apache.org/documentation.html#newconsumerconfigs">* configuration parameters</a> to be used on driver. The same params will be used on executors,* with minor automatic modifications applied.*  Requires "bootstrap.servers" to be set* with Kafka broker(s) specified in host1:port1,host2:port2 form.* @param offsets: offsets to begin at on initial startup.  If no offset is given for a* TopicPartition, the committed offset (if applicable) or kafka param* auto.offset.reset will be used.** 订阅一组topic消息*kafkaParams参数：*配置参数将会在driver上使用，并且相同参数也会发送到executor上使用，在executor上可能略微的配置修改*通知需要设置bootstrap.servers指定broker**offsets参数：* offsets伴随着startup开始,如果对于TopicPartition没有指定offset，* 提交的offset或auto.offset.reset将会被使用***/private case class Subscribe[K, V](topics: ju.Collection[jl.String],kafkaParams: ju.Map[String, Object],offsets: ju.Map[TopicPartition, jl.Long]) extends ConsumerStrategy[K, V] with Logging {/***继承至ConsumerStrategy的方法，获取配置参数** @return*/def executorKafkaParams: ju.Map[String, Object] = kafkaParams/****  继承至ConsumerStrategy的方法,用于创建Consumer* @return*/def onStart(currentOffsets: ju.Map[TopicPartition, jl.Long]): Consumer[K, V] = {val consumer = new KafkaConsumer[K, V](kafkaParams)consumer.subscribe(topics)val toSeek = if (currentOffsets.isEmpty) {offsets} else {currentOffsets}if (!toSeek.isEmpty) {// work around KAFKA-3370 when reset is none// poll will throw if no position, i.e. auto offset reset none and no explicit position// but cant seek to a position before poll, because poll is what gets subscription partitions// So, poll, suppress the first exception, then seekval aor = kafkaParams.get(ConsumerConfig.AUTO_OFFSET_RESET_CONFIG)val shouldSuppress = aor != null && aor.asInstanceOf[String].toUpperCase == "NONE"try {consumer.poll(0)} catch {case x: NoOffsetForPartitionException if shouldSuppress =>logWarning("Catching NoOffsetForPartitionException since " +ConsumerConfig.AUTO_OFFSET_RESET_CONFIG + " is none.  See KAFKA-3370")}toSeek.asScala.foreach { case (topicPartition, offset) =>consumer.seek(topicPartition, offset)}// we've called poll, we must pause or next poll may consume messages and set positionconsumer.pause(consumer.assignment())}consumer}}/*** Subscribe to all topics matching specified pattern to get dynamically assigned partitions.* The pattern matching will be done periodically against topics existing at the time of check.* @param pattern pattern to subscribe to* @param kafkaParams Kafka* <a href="http://kafka.apache.org/documentation.html#newconsumerconfigs">* configuration parameters</a> to be used on driver. The same params will be used on executors,* with minor automatic modifications applied.*  Requires "bootstrap.servers" to be set* with Kafka broker(s) specified in host1:port1,host2:port2 form.* @param offsets: offsets to begin at on initial startup.  If no offset is given for a* TopicPartition, the committed offset (if applicable) or kafka param* auto.offset.reset will be used.**  SubscribePattern是订阅所有匹配正则表达式模式的topic的数据*  topic模式匹配将会周期性的进行匹配，而不是在检查已存在的topic时候进行模式匹配**  kafkaParams参数：*配置参数将会在driver上使用，并且相同参数也会发送到executor上使用，在executor上可能略微的配置修改*通知需要设置bootstrap.servers指定broker**offsets参数：* offsets伴随着startup开始,如果对于TopicPartition没有指定offset，* 提交的offset或auto.offset.reset将会被使用***/private case class SubscribePattern[K, V](pattern: ju.regex.Pattern,kafkaParams: ju.Map[String, Object],offsets: ju.Map[TopicPartition, jl.Long]) extends ConsumerStrategy[K, V] with Logging {def executorKafkaParams: ju.Map[String, Object] = kafkaParamsdef onStart(currentOffsets: ju.Map[TopicPartition, jl.Long]): Consumer[K, V] = {val consumer = new KafkaConsumer[K, V](kafkaParams)consumer.subscribe(pattern, new NoOpConsumerRebalanceListener())val toSeek = if (currentOffsets.isEmpty) {offsets} else {currentOffsets}if (!toSeek.isEmpty) {// work around KAFKA-3370 when reset is none, see explanation in Subscribe aboveval aor = kafkaParams.get(ConsumerConfig.AUTO_OFFSET_RESET_CONFIG)val shouldSuppress = aor != null && aor.asInstanceOf[String].toUpperCase == "NONE"try {consumer.poll(0)} catch {case x: NoOffsetForPartitionException if shouldSuppress =>logWarning("Catching NoOffsetForPartitionException since " +ConsumerConfig.AUTO_OFFSET_RESET_CONFIG + " is none.  See KAFKA-3370")}toSeek.asScala.foreach { case (topicPartition, offset) =>consumer.seek(topicPartition, offset)}// we've called poll, we must pause or next poll may consume messages and set positionconsumer.pause(consumer.assignment())}consumer}}/*** Assign a fixed collection of TopicPartitions* @param topicPartitions collection of TopicPartitions to assign* @param kafkaParams Kafka* <a href="http://kafka.apache.org/documentation.html#newconsumerconfigs">* configuration parameters</a> to be used on driver. The same params will be used on executors,* with minor automatic modifications applied.*  Requires "bootstrap.servers" to be set* with Kafka broker(s) specified in host1:port1,host2:port2 form.* @param offsets: offsets to begin at on initial startup.  If no offset is given for a* TopicPartition, the committed offset (if applicable) or kafka param* auto.offset.reset will be used.**  订阅一个固定数目的TopicPartitions* kafkaParams参数：*配置参数将会在driver上使用，并且相同参数也会发送到executor上使用，在executor上可能略微的配置修改*通知需要设置bootstrap.servers指定broker**offsets参数：* offsets伴随着startup开始,如果对于TopicPartition没有指定offset，* 提交的offset或auto.offset.reset将会被使用****/private case class Assign[K, V](topicPartitions: ju.Collection[TopicPartition],kafkaParams: ju.Map[String, Object],offsets: ju.Map[TopicPartition, jl.Long]) extends ConsumerStrategy[K, V] {def executorKafkaParams: ju.Map[String, Object] = kafkaParamsdef onStart(currentOffsets: ju.Map[TopicPartition, jl.Long]): Consumer[K, V] = {val consumer = new KafkaConsumer[K, V](kafkaParams)consumer.assign(topicPartitions)val toSeek = if (currentOffsets.isEmpty) {offsets} else {currentOffsets}if (!toSeek.isEmpty) {// this doesn't need a KAFKA-3370 workaround, because partitions are known, no poll neededtoSeek.asScala.foreach { case (topicPartition, offset) =>consumer.seek(topicPartition, offset)}}consumer}}/*** :: Experimental ::* object for obtaining instances of [[ConsumerStrategy]]** 这个是订阅策略的工厂方法：用于实例化策略的****/@Experimentalobject ConsumerStrategies {/***  :: Experimental ::* Subscribe to a collection of topics.* @param topics collection of topics to subscribe* @param kafkaParams Kafka* <a href="http://kafka.apache.org/documentation.html#newconsumerconfigs">* configuration parameters</a> to be used on driver. The same params will be used on executors,* with minor automatic modifications applied.*  Requires "bootstrap.servers" to be set* with Kafka broker(s) specified in host1:port1,host2:port2 form.* @param offsets: offsets to begin at on initial startup.  If no offset is given for a* TopicPartition, the committed offset (if applicable) or kafka param* auto.offset.reset will be used.*/@Experimentaldef Subscribe[K, V](topics: Iterable[jl.String],kafkaParams: collection.Map[String, Object],offsets: collection.Map[TopicPartition, Long]): ConsumerStrategy[K, V] = {new Subscribe[K, V](new ju.ArrayList(topics.asJavaCollection),new ju.HashMap[String, Object](kafkaParams.asJava),new ju.HashMap[TopicPartition, jl.Long](offsets.mapValues(l => new jl.Long(l)).asJava))}/***  :: Experimental ::* Subscribe to a collection of topics.* @param topics collection of topics to subscribe* @param kafkaParams Kafka* <a href="http://kafka.apache.org/documentation.html#newconsumerconfigs">* configuration parameters</a> to be used on driver. The same params will be used on executors,* with minor automatic modifications applied.*  Requires "bootstrap.servers" to be set* with Kafka broker(s) specified in host1:port1,host2:port2 form.*/@Experimentaldef Subscribe[K, V](topics: Iterable[jl.String],kafkaParams: collection.Map[String, Object]): ConsumerStrategy[K, V] = {new Subscribe[K, V](new ju.ArrayList(topics.asJavaCollection),new ju.HashMap[String, Object](kafkaParams.asJava),ju.Collections.emptyMap[TopicPartition, jl.Long]())}/***  :: Experimental ::* Subscribe to a collection of topics.* @param topics collection of topics to subscribe* @param kafkaParams Kafka* <a href="http://kafka.apache.org/documentation.html#newconsumerconfigs">* configuration parameters</a> to be used on driver. The same params will be used on executors,* with minor automatic modifications applied.*  Requires "bootstrap.servers" to be set* with Kafka broker(s) specified in host1:port1,host2:port2 form.* @param offsets: offsets to begin at on initial startup.  If no offset is given for a* TopicPartition, the committed offset (if applicable) or kafka param* auto.offset.reset will be used.*/@Experimentaldef Subscribe[K, V](topics: ju.Collection[jl.String],kafkaParams: ju.Map[String, Object],offsets: ju.Map[TopicPartition, jl.Long]): ConsumerStrategy[K, V] = {new Subscribe[K, V](topics, kafkaParams, offsets)}/***  :: Experimental ::* Subscribe to a collection of topics.* @param topics collection of topics to subscribe* @param kafkaParams Kafka* <a href="http://kafka.apache.org/documentation.html#newconsumerconfigs">* configuration parameters</a> to be used on driver. The same params will be used on executors,* with minor automatic modifications applied.*  Requires "bootstrap.servers" to be set* with Kafka broker(s) specified in host1:port1,host2:port2 form.*/@Experimentaldef Subscribe[K, V](topics: ju.Collection[jl.String],kafkaParams: ju.Map[String, Object]): ConsumerStrategy[K, V] = {new Subscribe[K, V](topics, kafkaParams, ju.Collections.emptyMap[TopicPartition, jl.Long]())}/** :: Experimental ::* Subscribe to all topics matching specified pattern to get dynamically assigned partitions.* The pattern matching will be done periodically against topics existing at the time of check.* @param pattern pattern to subscribe to* @param kafkaParams Kafka* <a href="http://kafka.apache.org/documentation.html#newconsumerconfigs">* configuration parameters</a> to be used on driver. The same params will be used on executors,* with minor automatic modifications applied.*  Requires "bootstrap.servers" to be set* with Kafka broker(s) specified in host1:port1,host2:port2 form.* @param offsets: offsets to begin at on initial startup.  If no offset is given for a* TopicPartition, the committed offset (if applicable) or kafka param* auto.offset.reset will be used.*/@Experimentaldef SubscribePattern[K, V](pattern: ju.regex.Pattern,kafkaParams: collection.Map[String, Object],offsets: collection.Map[TopicPartition, Long]): ConsumerStrategy[K, V] = {new SubscribePattern[K, V](pattern,new ju.HashMap[String, Object](kafkaParams.asJava),new ju.HashMap[TopicPartition, jl.Long](offsets.mapValues(l => new jl.Long(l)).asJava))}/** :: Experimental ::* Subscribe to all topics matching specified pattern to get dynamically assigned partitions.* The pattern matching will be done periodically against topics existing at the time of check.* @param pattern pattern to subscribe to* @param kafkaParams Kafka* <a href="http://kafka.apache.org/documentation.html#newconsumerconfigs">* configuration parameters</a> to be used on driver. The same params will be used on executors,* with minor automatic modifications applied.*  Requires "bootstrap.servers" to be set* with Kafka broker(s) specified in host1:port1,host2:port2 form.*/@Experimentaldef SubscribePattern[K, V](pattern: ju.regex.Pattern,kafkaParams: collection.Map[String, Object]): ConsumerStrategy[K, V] = {new SubscribePattern[K, V](pattern,new ju.HashMap[String, Object](kafkaParams.asJava),ju.Collections.emptyMap[TopicPartition, jl.Long]())}/** :: Experimental ::* Subscribe to all topics matching specified pattern to get dynamically assigned partitions.* The pattern matching will be done periodically against topics existing at the time of check.* @param pattern pattern to subscribe to* @param kafkaParams Kafka* <a href="http://kafka.apache.org/documentation.html#newconsumerconfigs">* configuration parameters</a> to be used on driver. The same params will be used on executors,* with minor automatic modifications applied.*  Requires "bootstrap.servers" to be set* with Kafka broker(s) specified in host1:port1,host2:port2 form.* @param offsets: offsets to begin at on initial startup.  If no offset is given for a* TopicPartition, the committed offset (if applicable) or kafka param* auto.offset.reset will be used.*/@Experimentaldef SubscribePattern[K, V](pattern: ju.regex.Pattern,kafkaParams: ju.Map[String, Object],offsets: ju.Map[TopicPartition, jl.Long]): ConsumerStrategy[K, V] = {new SubscribePattern[K, V](pattern, kafkaParams, offsets)}/** :: Experimental ::* Subscribe to all topics matching specified pattern to get dynamically assigned partitions.* The pattern matching will be done periodically against topics existing at the time of check.* @param pattern pattern to subscribe to* @param kafkaParams Kafka* <a href="http://kafka.apache.org/documentation.html#newconsumerconfigs">* configuration parameters</a> to be used on driver. The same params will be used on executors,* with minor automatic modifications applied.*  Requires "bootstrap.servers" to be set* with Kafka broker(s) specified in host1:port1,host2:port2 form.*/@Experimentaldef SubscribePattern[K, V](pattern: ju.regex.Pattern,kafkaParams: ju.Map[String, Object]): ConsumerStrategy[K, V] = {new SubscribePattern[K, V](pattern,kafkaParams,ju.Collections.emptyMap[TopicPartition, jl.Long]())}/***  :: Experimental ::* Assign a fixed collection of TopicPartitions* @param topicPartitions collection of TopicPartitions to assign* @param kafkaParams Kafka* <a href="http://kafka.apache.org/documentation.html#newconsumerconfigs">* configuration parameters</a> to be used on driver. The same params will be used on executors,* with minor automatic modifications applied.*  Requires "bootstrap.servers" to be set* with Kafka broker(s) specified in host1:port1,host2:port2 form.* @param offsets: offsets to begin at on initial startup.  If no offset is given for a* TopicPartition, the committed offset (if applicable) or kafka param* auto.offset.reset will be used.*/@Experimentaldef Assign[K, V](topicPartitions: Iterable[TopicPartition],kafkaParams: collection.Map[String, Object],offsets: collection.Map[TopicPartition, Long]): ConsumerStrategy[K, V] = {new Assign[K, V](new ju.ArrayList(topicPartitions.asJavaCollection),new ju.HashMap[String, Object](kafkaParams.asJava),new ju.HashMap[TopicPartition, jl.Long](offsets.mapValues(l => new jl.Long(l)).asJava))}/***  :: Experimental ::* Assign a fixed collection of TopicPartitions* @param topicPartitions collection of TopicPartitions to assign* @param kafkaParams Kafka* <a href="http://kafka.apache.org/documentation.html#newconsumerconfigs">* configuration parameters</a> to be used on driver. The same params will be used on executors,* with minor automatic modifications applied.*  Requires "bootstrap.servers" to be set* with Kafka broker(s) specified in host1:port1,host2:port2 form.*/@Experimentaldef Assign[K, V](topicPartitions: Iterable[TopicPartition],kafkaParams: collection.Map[String, Object]): ConsumerStrategy[K, V] = {new Assign[K, V](new ju.ArrayList(topicPartitions.asJavaCollection),new ju.HashMap[String, Object](kafkaParams.asJava),ju.Collections.emptyMap[TopicPartition, jl.Long]())}/***  :: Experimental ::* Assign a fixed collection of TopicPartitions* @param topicPartitions collection of TopicPartitions to assign* @param kafkaParams Kafka* <a href="http://kafka.apache.org/documentation.html#newconsumerconfigs">* configuration parameters</a> to be used on driver. The same params will be used on executors,* with minor automatic modifications applied.*  Requires "bootstrap.servers" to be set* with Kafka broker(s) specified in host1:port1,host2:port2 form.* @param offsets: offsets to begin at on initial startup.  If no offset is given for a* TopicPartition, the committed offset (if applicable) or kafka param* auto.offset.reset will be used.*/@Experimentaldef Assign[K, V](topicPartitions: ju.Collection[TopicPartition],kafkaParams: ju.Map[String, Object],offsets: ju.Map[TopicPartition, jl.Long]): ConsumerStrategy[K, V] = {new Assign[K, V](topicPartitions, kafkaParams, offsets)}/***  :: Experimental ::* Assign a fixed collection of TopicPartitions* @param topicPartitions collection of TopicPartitions to assign* @param kafkaParams Kafka* <a href="http://kafka.apache.org/documentation.html#newconsumerconfigs">* configuration parameters</a> to be used on driver. The same params will be used on executors,* with minor automatic modifications applied.*  Requires "bootstrap.servers" to be set* with Kafka broker(s) specified in host1:port1,host2:port2 form.*/@Experimentaldef Assign[K, V](topicPartitions: ju.Collection[TopicPartition],kafkaParams: ju.Map[String, Object]): ConsumerStrategy[K, V] = {new Assign[K, V](topicPartitions,kafkaParams,ju.Collections.emptyMap[TopicPartition, jl.Long]())}}

本文到此结束，其余见Spark整合kafka0.10.0新特性(二)

补充：由于csdn博客编辑器偶尔出现对java代码排版出错问题，所以为了避免博文写的太长出错前功尽弃，所以将拆分多个博文讲解。