1.定义常量：

public enum Color {    RED,ORANGE,YELLOW,GREEN,INDIGO,BLUE,PURPLE}

2.用于switch： 

enum Color {    RED,ORANGE,YELLOW,GREEN,INDIGO,BLUE,PURPLE}public class Draw{    Color c = Color.BLUE;    public void draw(){        switch(c){        case RED:            c = Color.RED;            break;        case ORANGE:            c = Color.ORANGE;            break;        case YELLOW:            c = Color.YELLOW;            break;        case GREEN:            c = Color.GREEN;            break;        case INDIGO:            c = Color.INDIGO;            break;        case BLUE:            c = Color.BLUE;            break;        case PURPLE:            c = Color.PURPLE;            break;        }    }} 

3.在枚举中添加新方法：

public enum Color {    RED(1,"红"),    ORANGE(2,"橙"),    YELLOW(3,"黄"),    GREEN(4,"绿"),    INDIGO(5,"靛"),    BLUE(6,"蓝"),    PURPLE(7,"紫");    //成员变量    private int sequence;    private String name;    //构造方法    private Color(int sequence, String name) {        this.sequence = sequence;        this.name = name;    }    //自定义方法    public static String getColorName(int sequence){        for (Color c : Color.values()) {            if(c.getSequence() == sequence)                return c.name;        }        return null;    }    //getter&setter    public int getSequence() {        return sequence;    }    public void setSequence(int sequence) {        this.sequence = sequence;    }    public String getName() {        return name;    }    public void setName(String name) {        this.name = name;    }}

4.覆盖（重写）枚举的方法：

public enum Color {    RED(1,"红"),    ORANGE(2,"橙"),    YELLOW(3,"黄"),    GREEN(4,"绿"),    INDIGO(5,"靛"),    BLUE(6,"蓝"),    PURPLE(7,"紫");    //成员变量    private int sequence;    private String name;    //构造方法    private Color(int sequence, String name) {        this.sequence = sequence;        this.name = name;    }    //覆盖方法    @Override    public String toString() {        return "顺序："+this.sequence+"_颜色名："+this.name;    }}

5.实现接口：

interface Action{    void getDetail();}public enum Color implements Action{    RED(1,"红"),    ORANGE(2,"橙"),    YELLOW(3,"黄"),    GREEN(4,"绿"),    INDIGO(5,"靛"),    BLUE(6,"蓝"),    PURPLE(7,"紫");    //成员变量    private int sequence;    private String name;    //构造方法    private Color(int sequence, String name) {        this.sequence = sequence;        this.name = name;    }    @Override    public void getDetail() {        System.out.println("顺序："+this.sequence+"_颜色名："+this.name);    }}

6.使用接口组织枚举：

public interface Food {      enum Coffee implements Food{          BLACK_COFFEE,DECAF_COFFEE,LATTE,CAPPUCCINO      }      enum Dessert implements Food{          FRUIT, CAKE, GELATO      }  }

7.枚举集合：

java.util.EnumSet和java.util.EnumMap是两个枚举集合。EnumSet保证集合中的元素不重复；EnumMap中的key是enum类型，而value则可以是任意类型。