假期二

Spark提供的数据集操作类型有很多种，大致分为：转换操作和行动操作两大类，即对RDD的操作，RDD相关操作较多，这里不做表述。此外各个处理节点之间的通信模型不再像Hadoop只有Shuffle一种模式，用户可以命名、物化，控制中间结果的存储、分区等。下载完Spark后，启动spark shell 然后建在了spark自带的本地测试文件，以及简单的RDD操作和退出spark shell。

case class Point(var x:Double,var y:Double) extends Drawable{

def  shift(deltaX : Double,deltaY : Double){x+ = deltaX;y+ = deltaY}
}
trait  Drawable{
def  draw(){println( this .toString)}
}
abstract  class  Shape( var  location : Point){ //location是Shape的一个可变字段
def  moveTo(newLocation : Point){  //默认实现，只是修改位置
location  =  newLocation
}
 def  zoom(scale : Double)
}
class  Line(beginPoint : Point, var  endPoint : Point)  extends
Shape(beginPoint)  with  Drawable{
override  def  draw(){
println(s "Line:(${location.x},${location.y})--(${endPoint.x},${endPoint.y})" )
}
override  def  moveTo(newLocation : Point){
endPoint.shift(newLocation.x - location.x,newLocation.y -
location.y)  //直线移动时，先移动另外一个端点
location  =  newLocation  //移动位置
}
override  def  zoom(scale : Double){
val  midPoint  =  Point((endPoint.x + location.x)/ 2 ,(endPoint.y +
location.y)/ 2 )  //求出中点，并按中点进行缩放
location.x  =  midPoint.x + scale * (location.x - midPoint.x)
location.y  =  midPoint.y + scale * (location.y -midPoint.y)
endPoint.x  =  midPoint.x + scale * (endPoint.x - midPoint.x)
endPoint.y  =  midPoint.y + scale * (endPoint.y -midPoint.y)
}}
class  Circle(center : Point, var  radius : Double)  extends  Shape(center)
with  Drawable{
override  def  draw(){
println(s "Circle center:(${location.x},${location.y}),R=$radius" )
}
override  def  zoom(scale : Double){
radius  =  radius*scale  //对圆的缩放只用修改半径
} }
object  MyDraw{
 def  main(args :  Array[String]) {
 val  p = new  Point( 10 , 30 )
p.draw;
val  line 1  =  new  Line(Point( 0 , 0 ),Point( 20 , 20 ))
line 1 .draw
line 1 .moveTo(Point( 5 , 5 ))
line 1 .draw
line 1 .zoom( 2 )
line 1 .draw
val  cir =  new  Circle(Point( 10 , 10 ), 5 )
cir.draw
cir.moveTo(Point( 30 , 20 ))
cir.draw
cir.zoom( 0.5 )
cir.draw
 } }