1.目的

    找出人际关系圈中的三角环状关系（A->B,B->C,C->A）

2.素材

    text1.txt

1 tom 2 jack friend2 jack 3 sala friend3 sala 1 tom friend4 joy 1 tom friend1 tom 4 joy friend1 tom 4 joy friend2 jack 5 Missing friend

3.代码

package testimport org.apache.log4j.{Level, Logger}import org.apache.spark.{SparkContext, SparkConf}import org.apache.spark.graphx._import org.apache.spark.rdd.RDDobject join {  def main(args: Array[String]) {    //屏蔽日志    Logger.getLogger("org.apache.spark").setLevel(Level.WARN)    Logger.getLogger("org.eclipse.jetty.server").setLevel(Level.OFF)    //设置运行环境    val conf = new SparkConf().setAppName("test1").setMaster("local")    val sc = new SparkContext(conf)    //引入text文件    val File:RDD[String] = sc.textFile("e:\\text1.txt")    //创建两个列反向的RDD    //aid1,aid2    val edgea = File.map { e =>      val fields = e.split(" ")      (fields(0).toLong,fields(2).toLong)    }    //bid1,bid2    val edged = File.map { e =>      val fields = e.split(" ")      (fields(2).toLong,fields(0).toLong)    }    //RDD一次关联    val edge_rel=edgea.join(edged).map{case (aid1,(aid2,did2))=>(did2,(aid1,aid2))}    println("edge_rel:")    println(edge_rel.collect.mkString("\n"))    //RDD二次关联    val edge_final=edge_rel.join(edged).map{case (aid1,((aid2,aid3),aid4))=>(aid4,aid1,aid2,aid3)}    println("edge_final:")    println(edge_final.collect.mkString("\n"))    //筛选有向环    val edge_match=edge_final.filter{case (id1,id2,id3,id4)=>id1==id4}    println("edge_match:")    println(edge_match.collect.mkString("\n"))    //最终环状结构    val edge_tri=edge_match.map{case (id1,id2,id3,id4)=>(id1,id2,id3)}    println("edge_tri:")    println(edge_tri.collect.mkString("\n"))    //环状结构去重    val edge_unique=edge_tri.filter{case (id1,id2,id3)=>id1

4.输出

edge_rel:(1,(4,1))(1,(4,1))(3,(1,2))(4,(1,2))(3,(1,4))(4,(1,4))(3,(1,4))(4,(1,4))(2,(3,1))(1,(2,3))(1,(2,5))edge_final:(1,4,1,2)(1,4,1,2)(1,4,1,4)(1,4,1,4)(1,4,1,4)(1,4,1,4)(3,1,4,1)(4,1,4,1)(3,1,4,1)(4,1,4,1)(3,1,2,3)(4,1,2,3)(3,1,2,5)(4,1,2,5)(2,3,1,2)(2,3,1,4)(2,3,1,4)(1,2,3,1)edge_match:(3,1,2,3)(2,3,1,2)(1,2,3,1)edge_tri:(3,1,2)(2,3,1)(1,2,3)edge_unique:(1,2,3)