|NO.Z.00042|——————————|BigDataEnd|——|Hadoop&Scala.V04|——|Scala.v04|特质|特质继承类|

一、特质继承类

### --- 特质继承类
~~~     在Scala中，trait特质也可以继承class类，此时这个class类就会成为所有继承此trait的类的父类。

class MyUtil {
    def printMessage(msg: String) = println(msg)
}
// 特质Log继承MyUtil类
trait Log extends MyUtil {
    def log(msg: String) = printMessage(msg)
}
// Person3类继承Log特质，Log特质继承MyUtil类，所以MyUtil类成为Person3的父类
class Person3(name: String) extends Logger {
    def sayHello {
        log("Hello, " + name)
        printMessage("Hi, " + name)
    }
}

二、编程实现

### --- 编程代码

package yanqi.cn.part06

class MyUtil {
  def printMessage(msg: String): Unit = {
    println(msg)
  }
}

trait Log extends MyUtil {
  def log(msg: String): Unit = {
    println(msg)
  }
}
//Person3继承了Log特质，Log特质继承了MyUtil类，那么MyUtil类就成为Person3的父类
class Person3(name: String) extends Log {
  def sayHello: Unit = {
    log("hello, " + name)
    printMessage("hi, " + name)
  }
}

object TraitDemoFour {
  def main(args: Array[String]): Unit = {
    val person = new Person3("jacky")
    person.sayHello
  }
}

### --- 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=57126: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.part06.TraitDemoFour
hello, jacky
hi, jacky

Process finished with exit code 0

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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

                                                                                                                                                   ——W.S.Landor

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