寒假学习日报（四十八）

　　昨晚安装完sbt之后发现打包的时候又出BUG了，因此决定实验中的打包操作使用本机的IDEA进行，结合虚拟机中的Spark与Scala版本，在IDEA的pom.xml中引入下面这些东西：

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0"
         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>

    <groupId>org.example</groupId>
    <artifactId>ScoreAver</artifactId>
    <version>1.0-SNAPSHOT</version>

    <properties>
        <spark.version>2.2.3</spark.version>
        <scala.version>2.11</scala.version>
    </properties>


    <dependencies>
        <dependency>
            <groupId>org.apache.spark</groupId>
            <artifactId>spark-core_${scala.version}</artifactId>
            <version>${spark.version}</version>
        </dependency>
        <dependency>
            <groupId>org.apache.spark</groupId>
            <artifactId>spark-streaming_${scala.version}</artifactId>
            <version>${spark.version}</version>
        </dependency>
        <dependency>
            <groupId>org.apache.spark</groupId>
            <artifactId>spark-sql_${scala.version}</artifactId>
            <version>${spark.version}</version>
        </dependency>
        <dependency>
            <groupId>org.apache.spark</groupId>
            <artifactId>spark-hive_${scala.version}</artifactId>
            <version>${spark.version}</version>
        </dependency>
        <dependency>
            <groupId>org.apache.spark</groupId>
            <artifactId>spark-mllib_${scala.version}</artifactId>
            <version>${spark.version}</version>
        </dependency>
        <dependency>
            <groupId>org.scala-tools</groupId>
            <artifactId>maven-scala-plugin</artifactId>
            <version>2.11</version>
        </dependency>
        <dependency>
            <groupId>org.apache.maven.plugins</groupId>
            <artifactId>maven-eclipse-plugin</artifactId>
            <version>2.5.1</version>
        </dependency>
    </dependencies>

    <build>
        <plugins>
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-assembly-plugin</artifactId>
                <version>2.5.5</version>
                <configuration>
                    <archive>
                        <manifest>
                            <mainClass>Aver</mainClass>
                        </manifest>
                    </archive>
                    <descriptorRefs>
                        <descriptorRef>jar-with-dependencies</descriptorRef>
                    </descriptorRefs>
                </configuration>
                <executions>
                    <execution>
                        <id>make-assembly</id>
                        <phase>package</phase>
                        <goals>
                            <goal>single</goal>
                        </goals>
                    </execution>
                </executions>
            </plugin>
            <plugin>
                <groupId>org.scala-tools</groupId>
                <artifactId>maven-scala-plugin</artifactId>
                <executions>
                    <execution>
                        <goals>
                            <goal>compile</goal>
                            <goal>testCompile</goal>
                        </goals>
                    </execution>
                </executions>
                <configuration>
                    <scalaVersion>${scala.version}</scalaVersion>
                    <args>
                        <arg>-target:jvm-1.5</arg>
                    </args>
                </configuration>
            </plugin>

            <plugin>
                <artifactId>maven-compiler-plugin</artifactId>
                <version>3.6.0</version>
                <configuration>
                    <source>1.8</source>
                    <target>1.8</target>
                </configuration>
            </plugin>

            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-surefire-plugin</artifactId>
                <version>2.19</version>
                <configuration>
                    <skip>true</skip>
                </configuration>
            </plugin>

        </plugins>
    </build>

</project>

<mainClass>Aver</mainClass>这里指定运行jar时的调用入口，与object要一致，我这里没有创建package，否则格式是：包名.类名：

import org.apache.spark.SparkContext
import org.apache.spark.SparkContext._
import org.apache.spark.SparkConf

object Aver {
  def main(args: Array[String]): Unit = {
    val conf = new SparkConf().setAppName("Aver")
    val sc = new SparkContext(conf)
    val scoredata = sc.textFile("file:///home/hadoop02/Downloads/StudGrade")
    val res = scoredata.filter(_.trim().length>0).map(line=>(line.split(",")(0).trim(),line.split(",")(1).trim().toInt))
      .groupByKey()
      .map(x=>{
        var num = 0.0
        var sum = 0
        for(i <- x._2){
          sum = sum + i
          num = num + 1
        }
        val avg = sum/num
        val format = f"$avg%1.2f".toDouble
        (x._1,format)
      }).collect.foreach(x=>println(x._1+"	"+x._2))
  }
}

打包操作就是Maven的流程：