Java15 Record的sealed密封类

由于默认情况下Record是final的，并且可以继承接口。我们可以定义密封接口并让Record实现它们以更好地管理代码。

 Record的sealed密封类的示例

ApiTester.java

public class APITester {
   public static void main(String[] args) {
      Person employee = new Employee(23, "Robert");
      System.out.println(employee.id());
	   System.out.println(employee.name());
   }
}
sealed interface Person permits Employee, Manager {
   int id();
   String name();
}
record Employee(int id, String name) implements Person {}
record Manager(int id, String name) implements Person {}

编译并运行程序

$javac -Xlint:preview --enable-preview -source 15 APITester.java
$java --enable-preview APITester

输出结果为

23
Robert