目睹

object lj 
  trait FileLogger{
    val filename:String
    val writer = new FileWriter(filename)
    def writeLog(msg:String): Unit = {
      writer.write(msg)
      writer.close()
    }
  }

  class MyWriter extends FileLogger {
    override val filename: String = "test.log"
  }
  def main(args: Array[String]): Unit = {
    val log = new MyWriter()
    log.writeLog("测试内容")
  }
}
}