Spark：对数据实现TopN

野性酷女 2022-10-16 15:26 220阅读 0赞

### 对数据实现TopN ###

*   *  一、准备数据
     *   *  1.1 创建 topn.txt
         *  1.2 把数据上传到hdfs
     *  二、IDEA实现TopN功能
     *   *  2.1 导入依赖
         *  2.2 创建代码TopN

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[Spark MLlib 实现音乐推荐][Spark MLlib]  
[Spark：对数据实现TopN][Spark_TopN]

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**实验目的：**

1.  把数据上传至HDFS 。
2.  获取蜀国武将中武力值最高的5位，即通过分布式计算框架实现从原始数据查询出武力最高的Top5。

## 一、准备数据 ##

### 1.1 创建 topn.txt ###

1 刘备 68 蜀国
    2 马超 90 蜀国
    3 黄忠 91 蜀国
    4 魏延 76 蜀国
    5 姜维 92 蜀国
    6 关羽 96 蜀国
    7 严颜 78 蜀国
    8 孟达 64 蜀国
    9 张飞 88 蜀国
    10 马谡 76 蜀国
    11 赵云 95 蜀国
    12 法正 88 蜀国

### 1.2 把数据上传到hdfs ###

hadoop fs -put ./topn.txt /hdfs/topn.txt

![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dlaXhpbl80NDc3NTI1NQ_size_16_color_FFFFFF_t_70]

## 二、IDEA实现TopN功能 ##

### 2.1 导入依赖 ###

<properties>
            <scala.version>2.11.8</scala.version>
            <hadoop.version>2.7.3</hadoop.version>
            <spark.version>2.4.0</spark.version>
            <hbase.version>1.2.4</hbase.version>
        </properties>
    
        <dependencies>
            
            <dependency>
                <groupId>org.scala-lang</groupId>
                <artifactId>scala-library</artifactId>
                <version>${scala.version}</version>
            </dependency>
    
            
            <dependency>
                <groupId>org.apache.kafka</groupId>
                <artifactId>kafka-clients</artifactId>
                <version>2.4.0</version>
            </dependency>
    
            <dependency>
                <groupId>org.apache.kafka</groupId>
                <artifactId>kafka-streams</artifactId>
                <version>2.4.0</version>
            </dependency>
    
            
            <dependency>
                <groupId>org.apache.spark</groupId>
                <artifactId>spark-streaming-kafka-0-8_2.11</artifactId>
                <version>2.4.0</version>
            </dependency>
    
            
            <dependency>
                <groupId>org.apache.spark</groupId>
                <artifactId>spark-streaming-flume_2.11</artifactId>
                <version>2.3.0</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-streaming_2.11</artifactId>
                <version>2.4.0</version>
            </dependency>
    
            <dependency>
                <groupId>org.apache.spark</groupId>
                <artifactId>spark-sql_2.11</artifactId>
                <version>2.4.0</version>
            </dependency>
    
            <dependency>
                <groupId>org.apache.spark</groupId>
                <artifactId>spark-mllib_2.11</artifactId>
                <version>${spark.version}</version>
            </dependency>
    
            
            <dependency>
                <groupId>org.apache.hadoop</groupId>
                <artifactId>hadoop-client</artifactId>
                <version>${hadoop.version}</version>
            </dependency>
    
            <dependency>
                <groupId>org.apache.hadoop</groupId>
                <artifactId>hadoop-hdfs</artifactId>
                <version>${hadoop.version}</version>
            </dependency>
    
            
            <dependency>
                <groupId>org.apache.hbase</groupId>
                <artifactId>hbase-client</artifactId>
                <version>${hbase.version}</version>
            </dependency>
            <dependency>
                <groupId>org.apache.hbase</groupId>
                <artifactId>hbase-common</artifactId>
                <version>${hbase.version}</version>
            </dependency>
    
            <dependency>
                <groupId>mysql</groupId>
                <artifactId>mysql-connector-java</artifactId>
                <version>5.1.46</version>
            </dependency>
        </dependencies>

### 2.2 创建代码TopN ###

import org.apache.spark.{
        SparkConf, SparkContext}
    
    object TopN {
        
      def main(args: Array[String]): Unit = {
        
        // 1.创建 sparkConf
        val sparkConf: SparkConf = new SparkConf().setAppName("ToN").setMaster("local[2]")
        // 2.创建 SparkContext对象
        val sc:SparkContext = new SparkContext(sparkConf)
        // 3.设置日志级别
        sc.setLogLevel("WARN")
        // 4.读入数据且切分
        val data = sc.textFile("hdfs://master:8020/hdfs/topn.txt")
          .map(_.split(" ")).map(x => (x(0).toInt,x(1),x(2).toInt,x(3)))
        // 5.排序并输出Top结果
        data.sortBy(_._3,false).collect().take(5).foreach(println)
      }
    }

![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dlaXhpbl80NDc3NTI1NQ_size_16_color_FFFFFF_t_70 1]

[Spark MLlib]: https://blog.csdn.net/weixin_44775255/article/details/117435696
[Spark_TopN]: https://blog.csdn.net/weixin_44775255/article/details/117412442
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