scala实现观察者模式示例

package cn.touna

import scala.collection.mutable
import scala.collection.mutable.{ArrayBuffer, ListBuffer}

/**
* User: lijie
*/
abstract class Subject {
/**
* 注册观察者
*
* @param obs
*/
def registObserver(obs: Observer): Unit

/**
* 注销观察者
*
* @param obs
*/
def removeObserver(obs: Observer): Unit

/**
* 通知观察者
*/
def notifyObserver(name: String, age: Int): Unit
}

abstract class Observer {

/**
* 更新方法
*
* @param name
* @param age
*/
def update(name: String, age: Int): Unit
}

class SubjectImpl extends Subject {

//注册中心
var list = new ListBuffer[Observer]

/**
* 注册观察者
*
* @param obs
*/
override def registObserver(obs: Observer): Unit = {
list += obs
}

/**
* 注销观察者
*
* @param obs
*/
override def removeObserver(obs: Observer): Unit = {
list -= obs
}

/**
* 通知观察者
*/
override def notifyObserver(name: String, age: Int): Unit = {
list.foreach(x => {
x.update(name, age)
})
}
}

class ObserverImpl(val sub: Subject, var name: String = null, var age: Int = 0) extends Observer {

//构造函数调用
online

/**
* 观察者上线
*/
def online(): Unit = {
sub.registObserver(this)
}

/**
* 观察者下线
*
* @return
*/
def offline(): Unit = {
sub.removeObserver(this)
}

/**
* 更新方法
*
* @param name
* @param age
*/
override def update(name: String, age: Int): Unit = {
this.name = name
this.age = age
showInfo
}

def showInfo(): Unit = {
println(s"current  name: $name , age: $age")
}

}

/**
* 主函数入口
*/
object Obs {
def main(args: Array[String]): Unit = {
//创建主题
val subject = new SubjectImpl
//创建观察者
val observer01 = new ObserverImpl(subject)
val observer02 = new ObserverImpl(subject)

subject.notifyObserver("zhangsan", 24)
println("-------------------------")
subject.notifyObserver("wangwu", 24)

}
}