java - 如何让 "Enum.CONSTANT"返回某种类型(例如颜色)？

Question

我希望枚举的字段常量返回 Color 类的实例而不是一些常量值，这在 Java 中可能吗？我想避免通过访问器方法检索它们。例如，这是我希望能够使用枚举的方式:

Color color;
color = ExtendedColor.RED;
color = ExtendedColor.FOO;
color = ExtendedColor.BAZ;

---

import java.awt.*;

/**
 * Static utility enum for providing a much greater variety of Colors to choose from, some of which are not
 * included as constants in the Color class
 */
public enum ExtendedColor {
    RED(Color.RED),
    ORANGE(Color.ORANGE),
    YELLOW(Color.YELLOW),
    FOO(10, 20, 30),
    BAR(90, 90, 90),
    BAZ(30, 30, 30);

    private Color color;

    private ExtendedColor(Color color) {
        this.color = color;
    }

    private ExtendedColor(int r, int g, int b) {
        this.color = new Color(r, g, b);
    }
}

Answer 1

您可以创建一个包含公共(public)静态字段的类，并直接访问这些字段ExtendedColor.COLOR1。

import java.awt.*;

public class ExtendedColor {
    public static final Color COLOR1 = ...;
    public static final Color COLOR2 = ...;
    ...
}