在Java中，枚舉類型使用enum關鍵字來定義。枚舉類型可以包含常量、方法和構造函數。以下是枚舉類型的一些使用方法：

1. 定義枚舉類型：

public enum Day {
    MONDAY, TUESDAY, WEDNESDAY, THURSDAY, FRIDAY, SATURDAY, SUNDAY
}

2. 訪問枚舉常量：

Day day = Day.MONDAY;
System.out.println(day); // 輸出 MONDAY

3. 使用枚舉類型中的方法：

public enum Day {
    MONDAY, TUESDAY, WEDNESDAY, THURSDAY, FRIDAY, SATURDAY, SUNDAY;
    
    public boolean isWeekend() {
        return this == SATURDAY || this == SUNDAY;
    }
}

Day day = Day.SATURDAY;
System.out.println(day.isWeekend()); // 輸出 true

4. 使用values()方法獲取枚舉常量數組：

Day[] days = Day.values();
for (Day day : days) {
    System.out.println(day);
}

5. 使用valueOf()方法根據字符串獲取枚舉常量：

Day day = Day.valueOf("MONDAY");
System.out.println(day); // 輸出 MONDAY

6. 實現枚舉類型的構造函數和方法：

public enum Day {
    MONDAY("Monday"), TUESDAY("Tuesday"), WEDNESDAY("Wednesday"), THURSDAY("Thursday"), FRIDAY("Friday"), SATURDAY("Saturday"), SUNDAY("Sunday");
    
    private String displayName;
    
    Day(String displayName) {
        this.displayName = displayName;
    }
    
    public String getDisplayName() {
        return displayName;
    }
}

Day day = Day.MONDAY;
System.out.println(day.getDisplayName()); // 輸出 Monday