java - 是否可以将传递给方法的参数限制为常量？

Question

我有一个有一些常量的类，我有一个方法，我喜欢将它的参数限制为类中定义的那些常量，有没有办法在 java 中实现这一点？

Answer 1

Use enums for this. They are constants that allow for compile-time type checking, and in fact this is one of the very reasons that they were created.

Answer 2

常数：

enum DistanceUnit {
  MILE,
  KILOMETER
}

double calculateCaloriesBurned (double distanceWalked, DistanceUnit unit);

同样，假设您不喜欢人们走负距离：

class Distance {
  private double value;

  public Distance (value) {
    if (value < 0) { throw new IllegalArgumentException(); }
    ...
  }
}

double calculateCaloriesBurned (Distance distanceWalked, DistanceUnit unit);