### --- 隐式转换案例
~~~ 隐式转换案例:特殊售票窗口(只接受特殊人群买票,比如学生、老人等),
~~~ 其他人不能在特殊售票窗口买票。
class SpecialPerson(var name: String)
class Older(var name: String)
class Student(var name: String)
class Worker(var name: String)
object ImplicitDemoTwo {
def buySpecialTickWindow(person: SpecialPerson): Unit = {
if (peron != null) {
println(person.name + "购买了一张特殊票!")
} else {
println("你不是特殊人群,不能在此买票!")
}
}
//隐式转换函数
//注意:any参数的类型是Any
implicit def any2SpecialPerson(any: Any): SpecialPerson = {
any match {
case any: Older => new SpecialPerson(any.asInstanceOf[Older].name)
case any: Student => new SpecialPerson(any.asInstanceOf[Student].name)
case _ => null
}
}
def main(args: Array[String]): Unit = {
val stu = new Student("jacky")
val older = new Older("old man")
val worker = new Worker("tom")
ImplicitDemoTwo.buySpecialTickWindow(stu)
ImplicitDemoTwo.buySpecialTickWindow(older)
ImplicitDemoTwo.buySpecialTickWindow(worker)
}
}
### --- 编程代码
package yanqi.cn.part10
class SpecialPerson(var name: String)
class Older(var name: String)
class Student(var name: String)
class Worker(var name: String)
object ImplicitDemoTwo {
def buySpecialTickWindow(person: SpecialPerson): Unit = {
if (person != null) {
println(person.name + "购买了一张特殊票!")
} else {
println("你不是特殊人群,不能在此购票!")
}
}
//定义一个隐式转换函数
implicit def any2SpecialPerson(any: Any): SpecialPerson = {
any match {
case any: Older => new SpecialPerson(any.asInstanceOf[Older].name)
case any: Student => new SpecialPerson(any.asInstanceOf[Student].name)
case _ => null
}
}
def main(args: Array[String]): Unit = {
val stu = new Student("jacky")
val older = new Older("old man")
val worker = new Worker("lisi")
buySpecialTickWindow(stu)
buySpecialTickWindow(older)
buySpecialTickWindow(worker)
}
}
### --- 编译打印
D:\JAVA\jdk1.8.0_231\bin\java.exe "-javaagent:D:\IntelliJIDEA\IntelliJ IDEA 2019.3.3\lib\idea_rt.jar=61235:D:\IntelliJIDEA\IntelliJ IDEA 2019.3.3\bin" -Dfile.encoding=UTF-8 -classpath D:\JAVA\jdk1.8.0_231\jre\lib\charsets.jar;D:\JAVA\jdk1.8.0_231\jre\lib\deploy.jar;D:\JAVA\jdk1.8.0_231\jre\lib\ext\access-bridge-64.jar;D:\JAVA\jdk1.8.0_231\jre\lib\ext\cldrdata.jar;D:\JAVA\jdk1.8.0_231\jre\lib\ext\dnsns.jar;D:\JAVA\jdk1.8.0_231\jre\lib\ext\jaccess.jar;D:\JAVA\jdk1.8.0_231\jre\lib\ext\jfxrt.jar;D:\JAVA\jdk1.8.0_231\jre\lib\ext\localedata.jar;D:\JAVA\jdk1.8.0_231\jre\lib\ext\nashorn.jar;D:\JAVA\jdk1.8.0_231\jre\lib\ext\sunec.jar;D:\JAVA\jdk1.8.0_231\jre\lib\ext\sunjce_provider.jar;D:\JAVA\jdk1.8.0_231\jre\lib\ext\sunmscapi.jar;D:\JAVA\jdk1.8.0_231\jre\lib\ext\sunpkcs11.jar;D:\JAVA\jdk1.8.0_231\jre\lib\ext\zipfs.jar;D:\JAVA\jdk1.8.0_231\jre\lib\javaws.jar;D:\JAVA\jdk1.8.0_231\jre\lib\jce.jar;D:\JAVA\jdk1.8.0_231\jre\lib\jfr.jar;D:\JAVA\jdk1.8.0_231\jre\lib\jfxswt.jar;D:\JAVA\jdk1.8.0_231\jre\lib\jsse.jar;D:\JAVA\jdk1.8.0_231\jre\lib\management-agent.jar;D:\JAVA\jdk1.8.0_231\jre\lib\plugin.jar;D:\JAVA\jdk1.8.0_231\jre\lib\resources.jar;D:\JAVA\jdk1.8.0_231\jre\lib\rt.jar;E:\NO.Z.10000——javaproject\NO.Z.00002.Hadoop\ScalaPro\out\production\ScalaPro;D:\JAVA\scala-2.12.2\lib\scala-library.jar;D:\JAVA\scala-2.12.2\lib\scala-reflect.jar yanqi.cn.part10.ImplicitDemoTwo
jacky购买了一张特殊票!
old man购买了一张特殊票!
你不是特殊人群,不能在此购票!
Process finished with exit code 0
Walter Savage Landor:strove with none,for none was worth my strife.Nature I loved and, next to Nature, Art:I warm'd both hands before the fire of life.It sinks, and I am ready to depart