SCALA当的trait

不是特别懂，但感觉和RUBY当中的MIX-IN功能有几分相似，这又扯到了多重继承及JAVA当中的接口虚拟类了。。

package com.hengheng.scala

class UseTrait {

}
trait Logger {
  def log(msg : String) {
    println("log : " + msg)
  }
}
trait ConsoleLogger extends Logger {
  override def log(msg : String) {
    println(msg)
  }
}
class Test extends ConsoleLogger {
  def test() {
    log("Here is Spark!")
  }
}
class ConcreteLogger extends Logger {
  def concreteLog {
    log("It's me!")
  }
}
object UseTrait extends App {
  var logger = new ConcreteLogger
  logger.concreteLog
  var test = new Test
  test.test
}

　　输出：

log : It's me!
Here is Spark!