scala抽象类实战
实战一:
声明一个抽象类(SuperTeacher):(超级老师)
abstract class SuperTeacher(val name : String){ var id : Int var age : Int def teach }
一个不可变属性,和两个可变属性(主键和年龄),一个未实现方法(教书)
声明一个子类(TeacherForMaths):
class TeacherForMaths(name : String) extends SuperTeacher(name){ override var id = name.hashCode() override var age = 29 override def teach{ println("Teaching!!!") } }
抽象类的测试类
object AbstractClassOps{ def main(args: Array[String]) { val teacher = new TeacherForMaths("Spark") teacher.teach println("teacher.id" + ":" + teacher.id) println(teacher.name + ":" + teacher.age) } }
实战二:
抽象事件类:event,对于一个事件来说,事件名称决定他的不同,所以名称是不可变的,可以将时间和内容的不同来区分不同的事件
/** * 事件的抽象类,由事件的三要素组成,事件名称、发生时间(时间戳) * 事件内容 * @param name 事件名称 */ abstract class Event(val name:String) { var time:Long var content:String }
子类基本事件类,子类必须实现父类的未实现的属性的方法,如果不想先初始化,可以用占位符先占用位置,子类中有apply的方法重载。
/** * 基本事件类,继承时间的抽象类 * @param name 事件名称 */ class BaseEvent(name: String) extends Event(name) { var id: String = _ override var time: Long = _ override var content: String = _ override def toString():String ={ id+","+name+","+time+","+content } }
object BaseEvent { def apply(name: String): BaseEvent = { val event = new BaseEvent(name) event } def apply(name: String, id: String): BaseEvent = { val event = apply(name) event.id = id event } def apply(name: String, id: String, time: Long): BaseEvent = { val event = apply(name, id) event.time = time event } def apply(name: String, id: String, time: Long, content: String): BaseEvent = { val event = apply(name, id, time) event.content = content event } def main(args: Array[String]) { val event = BaseEvent("name","shsh001",1200132392838L,"scjsncjscnsncas"); print(event.toString()) } }
执行结果:
shsh001,name,1200132392838,scjsncjscnsncas
作者:舆-风动名扬 出处:http://www.cnblogs.com/gnool/
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