Enum是一个有点特殊的类。枚举可以存储额外的字段，实现方法等。例如

public enum Modes {
    mode1('a'),
    mode2('b'),
    mode3('c'),
    ;
    char c;

    private Modes(char c) {
        this.c = c;
    }
    public char character() {
        return c;
    }
}

现在你可以说:

System.out.println (Modes.mode1.character ())

并查看输出: 一个

您可以为每个枚举值重写toString()方法。

例子:

public enum Country {

  DE {
    @Override
    public String toString() {
      return "Germany";
    }
  },
  IT {
    @Override
    public String toString() {
      return "Italy";
    }
  },
  US {
    @Override
    public String toString() {
      return "United States";
    }
  }

}

用法:

public static void main(String[] args) {
  System.out.println(Country.DE); // Germany
  System.out.println(Country.IT); // Italy
  System.out.println(Country.US); // United States
}

此方法适用于任何枚举:

public enum MyEnum {
    VALUE1,
    VALUE2,
    VALUE3;

    public int getValue() {
        return this.ordinal();
    }

    public static DataType forValue(int value) {
        return values()[value];
    }

    public String toString() {
        return forValue(getValue()).name();
    }
}

Enum是一个有点特殊的类。枚举可以存储额外的字段，实现方法等。例如

public enum Modes {
    mode1('a'),
    mode2('b'),
    mode3('c'),
    ;
    char c;

    private Modes(char c) {
        this.c = c;
    }
    public char character() {
        return c;
    }
}

现在你可以说:

System.out.println (Modes.mode1.character ())

并查看输出: 一个

我发现这个更容易防止输入错误:

public enum Modes {
    some-really-long-string,
    mode1,
    mode2,
    mode3;

    String str;

    Modes(){
        this.str = super.name();
    }

    @Override
    @NonNull
    public String toString() {
        return str;
    }

然而，当你需要在log/println上使用String时，或者当java自动编译toString()方法时，这可能会起作用，但在这样的代码行中->

// sample method that require (string,value)
intent.putExtra(Modes.mode1 ,shareElement.getMode()); // java error
// first argument enum does not return value

相反，如上所述，你仍然需要扩展枚举，并在这些情况下使用.name():

intent.putExtra(Modes.mode1.name() ,shareElement.getMode()); 

package com.common.test;

public  enum Days {


    monday(1,"Monday"),tuesday(2,"Tuesday"),wednesday(3,"Wednesday"),
    thrusday(4,"Thrusday"),friday(5,"Friday"),saturday(6,"Saturday"),sunday(7,"Sunday");

    private int id;
    private String desc;


    Days(int id,String desc){
        this.id=id;
        this.desc=desc;
    }

    public static String getDay(int id){

        for (Days day : Days.values()) {
            if (day.getId() == id) {
                return day.getDesc();
            }
        }
        return null;
    }

    public int getId() {
        return id;
    }

    public void setId(int id) {
        this.id = id;
    }

    public String getDesc() {
        return desc;
    }

    public void setDesc(String desc) {
        this.desc = desc;
    }



};