Spark Streaming

　　Spark Streaming 是基于spark的流式批处理引擎，其基本原理是把输入数据以某一时间间隔批量的处理，当批处理间隔缩短到秒级时，便可以用于处理实时数据流。

Spark Streaming入门小程序

第一步:

在Linux上执行以下命令安装socket客户端工具，模拟发送数据:　　yum -y install nc

执行以下命令，向指定的端口9999发送数据:　　nc -lk 9999
光标会一直闪烁,直接输入数据即可,例如:　　hello word

 

 

 第二步:

在idea中创建maven工程,命名为:Spark_Streaming,
分别在java与test中创建scala文件夹,赋予相应属性,打开pom.xml添加以下配置信息:

 <properties>
        <scala.version>2.11.8</scala.version>
        <spark.version>2.2.0</spark.version>
    </properties>
    <dependencies>
        <dependency>
            <groupId>org.scala-lang</groupId>
            <artifactId>scala-library</artifactId>
            <version>${scala.version}</version>
        </dependency>
        <dependency>
            <groupId>org.apache.spark</groupId>
            <artifactId>spark-core_2.11</artifactId>
            <version>${spark.version}</version>
        </dependency>
        <dependency>
            <groupId>org.apache.spark</groupId>
            <artifactId>spark-sql_2.11</artifactId>
            <version>${spark.version}</version>
        </dependency>
        <!-- https://mvnrepository.com/artifact/org.apache.spark/spark-streaming -->
        <dependency>
            <groupId>org.apache.spark</groupId>
            <artifactId>spark-streaming_2.11</artifactId>
            <version>2.2.0</version>
        </dependency>
        <dependency>
            <groupId>org.apache.hadoop</groupId>
            <artifactId>hadoop-client</artifactId>
            <version>2.7.5</version>
        </dependency>

        <dependency>
            <groupId>org.apache.spark</groupId>
            <artifactId>spark-hive_2.11</artifactId>
            <version>2.2.0</version>
        </dependency>

        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <version>5.1.38</version>
        </dependency>

    </dependencies>
    <build>
        <sourceDirectory>src/main/scala</sourceDirectory>
        <testSourceDirectory>src/test/scala</testSourceDirectory>
        <plugins>
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-compiler-plugin</artifactId>
                <version>3.0</version>
                <configuration>
                    <source>1.8</source>
                    <target>1.8</target>
                    <encoding>UTF-8</encoding>
                    <!--    <verbal>true</verbal>-->
                </configuration>
            </plugin>
            <plugin>
                <groupId>net.alchim31.maven</groupId>
                <artifactId>scala-maven-plugin</artifactId>
                <version>3.2.0</version>
                <executions>
                    <execution>
                        <goals>
                            <goal>compile</goal>
                            <goal>testCompile</goal>
                        </goals>
                        <configuration>
                            <args>
                                <arg>-dependencyfile</arg>
                                <arg>${project.build.directory}/.scala_dependencies</arg>
                            </args>
                        </configuration>
                    </execution>
                </executions>
            </plugin>
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-shade-plugin</artifactId>
                <version>3.1.1</version>
                <executions>
                    <execution>
                        <phase>package</phase>
                        <goals>
                            <goal>shade</goal>
                        </goals>
                        <configuration>
                            <filters>
                                <filter>
                                    <artifact>*:*</artifact>
                                    <excludes>
                                        <exclude>META-INF/*.SF</exclude>
                                        <exclude>META-INF/*.DSA</exclude>
                                        <exclude>META-INF/*.RSA</exclude>
                                    </excludes>
                                </filter>
                            </filters>
                            <transformers>
                                <transformer implementation="org.apache.maven.plugins.shade.resource.ManifestResourceTransformer">
                                    <mainClass></mainClass>
                                </transformer>
                            </transformers>
                        </configuration>
                    </execution>
                </executions>
            </plugin>
        </plugins>
    </build>

在java包中创建新的包,命名为:Streaming,在该包下新建一个属性为object的Scala class文件,并命名为:Streaming_Dome,编写以下代码:

package Streaming

import org.apache.spark.streaming.dstream.ReceiverInputDStream
import org.apache.spark.{SparkConf, SparkContext}
import org.apache.spark.streaming.{Seconds, StreamingContext}

object Streaming_Dome {
  def main(args: Array[String]): Unit = {
    val sparkContext = new SparkContext(new SparkConf().setMaster("local[6]").setAppName("StreamingContext"))
    sparkContext.setLogLevel("WARN")
    //创建streamingContext,有两个参数,每个3秒执行一次
    val streamingContext = new StreamingContext(sparkContext,Seconds(3))
    //调用streamingContext从socket当中获取数
    val textSteram: ReceiverInputDStream[String] = streamingContext.socketTextStream("master",9999)
    //将接收的数据打印出来
    textSteram.print()
    //启动streaming程序
    streamingContext.start()
    //程序等待 手动结束
    streamingContext.awaitTermination()
  }

}

运行Streaming_Dome程序

 

 成功!