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枚举的常用方法

转：https://www.cnblogs.com/liaojie970/p/6474733.html

用法一：常量

public enum Color {  
  RED, GREEN, BLANK, YELLOW  
}

用法二：switch

enum Signal {
        GREEN, YELLOW, RED
    }
 
    public class TrafficLight {
        Signal color = Signal.RED;
 
        public void change() {
            switch (color) {
            case RED:
                color = Signal.GREEN;
                break;
            case YELLOW:
                color = Signal.RED;
                break;
            case GREEN:
                color = Signal.YELLOW;
                break;
            }
        }
    }

用法三：向枚举中添加新方法

public enum Color {
    RED("红色", 1), GREEN("绿色", 2), BLANK("白色", 3), YELLO("黄色", 4);
    // 成员变量
    private String name;
    private int index;
 
    // 构造方法
    private Color(String name, int index) {
        this.name = name;
        this.index = index;
    }
 
    // 普通方法
    public static String getName(int index) {
        for (Color c : Color.values()) {
        if (c.getIndex() == index) {
            return c.name;
        }
        }
        return null;
    }
 
    // get set 方法
    public String getName() {
        return name;
    }
 
    public void setName(String name) {
        this.name = name;
    }
 
    public int getIndex() {
        return index;
    }
 
    public void setIndex(int index) {
        this.index = index;
    }
    }

用法四：覆盖枚举的方法

public class Test {
    public enum Color {
        RED("红色", 1), GREEN("绿色", 2), BLANK("白色", 3), YELLO("黄色", 4);
        // 成员变量
        private String name;
        private int index;
 
        // 构造方法
        private Color(String name, int index) {
            this.name = name;
            this.index = index;
        }
 
        // 覆盖方法
        @Override
        public String toString() {
            return this.index + "_" + this.name;
        }
    }
 
    public static void main(String[] args) {
        System.out.println(Color.RED.toString());
    }
}