枚举示例

1、周六周日是休息日

public enum EnumTest {
    MON(1), TUE(2), WED(3), THU(4), FRI(5), SAT(6) {
        @Override
        public boolean isRest() {
            return true;
        }
    },
    SUN(0) {
        @Override
        public boolean isRest() {
            return true;
        }
    };

    private int value;

    EnumTest(int value) {
        this.value = value;
    }

    public int getValue() {
        return value;
    }

    public boolean isRest() {
        return false;
    }
}

2、使用EnumSet创建枚举集 EnumMap集合的使用

public class Test {
    public static void main(String[] args) {
        // EnumSet的使用
        EnumSet<EnumTest> weekSet = EnumSet.allOf(EnumTest.class);
        for (EnumTest day : weekSet) {
            System.out.println(day);
        }
        System.out.println("========================================");

        // EnumMap的使用
        EnumMap<EnumTest, String> weekMap = new EnumMap(EnumTest.class);
        weekMap.put(EnumTest.MON, "星期一");
        weekMap.put(EnumTest.TUE, "星期二");
       
        for (Iterator<Map.Entry<EnumTest, String>> iter = weekMap.entrySet().iterator(); iter.hasNext();) {
            Map.Entry<EnumTest, String> entry = iter.next();
            System.out.println(entry.getKey().name() + ":" + entry.getValue());
        }
        System.out.println("=====================================================");
        Iterator<Map.Entry<EnumTest, String>> iter = weekMap.entrySet().iterator();
        while (iter.hasNext()){
            Map.Entry<EnumTest, String> entry = iter.next();
            System.out.println(entry.getKey().name() + ":" + entry.getValue());
        }
    }
}

3、根据输入进来的字符串，返回对应的枚举对象

public enum Day {
    monday("星期一",1),
    tuesday("星期二",2),
    wednesday("星期三",3),
    thursday("星期四",4),
    friday("星期五",5),
    saturday("星期六",6),
    sunday("星期日",7),
    星期一("monday",8),
    星期二("tuesday",9),
    星期三(wednesday.name,10 );

    //私有属性
    private String name;
    private int index;

    Day() {
    }
    //私有构造方法
    Day(String name, int index) {
        this.name = name;
        this.index = index;
    }

    public int getIndex() {
        return index;
    }
    public String getName() {
        return name;
    }
    //根据输入进来的字符串，返回对应的枚举对象
    public static Day getDay(String day){
        for (Day v:values()) {
            if (v.getName().equals(day)) {
                return v;
            }
        }
        return null;
    }
}

4、判断是否操作成功

public enum Code {
    SUCCESS(1000,"操作成功"),FAIL(1001,"操作失败");

    private int code;
    private String msg;

    Code(int code, String msg) {
        this.code = code;
        this.msg = msg;
    }

    public int getCode() {
        return code;
    }

    public String getMsg() {
        return msg;
    }

    public static Code getByValue(int value){
        for (Code code:values()){
            if (code.getCode() ==value){
                return code;
            }
        }
        return null;
    }
}

public class TestCode {
    public static void main(String[] args) {
        String msg = Code.SUCCESS.getMsg();
        String msg1 = Code.FAIL.getMsg();

        int code = 1001;
        switch(Code.getByValue(code)){
            case SUCCESS:
                System.out.println(msg); //操作成功
                break;
            case FAIL:
                System.out.println(msg1); //操作失败
                break;
            default:
                System.out.println("操作有误");
        }
    }
}