Color T = Color.red;
if (T == Color.red)
  System.out.println("i am red");
switch(T) {
 case red:
   System.out.println("i am red");
   break
}

enum color {red,green};
enum color a = 1;// a is green

enum color {
 red(1),green(2);
 private final int number;
 color(int i) {
  this.number = i;
 }
 public getValue() {
  return this.number;
 }
}

name, toString, valueOf //获取名字
equals //比较
ordinal //获取位置

enum number {
  zero(0),one(1),two(2);
  int n;
  number(int i) {
    this.n = i;
  }
  public int getValue(){
    return this.n;
  }
}
interface People_State {
  String getState();
  State_Enum ChangeState();
}
enum State_Enum implements People_State {
  normal("正常"), stop("停止");
  private final String state;
  State_Enum(String s) {
    this.state = s;
  }
  public String toString() {
    return state;
  }
  @Override
  public String getState() {
    return state;
  }
  @Override
  public State_Enum ChangeState() {
    if (this == normal)
      return stop;
    else
      return normal;
  }
}
public class Test_Enum {
  public static void main(String[] args) {
    number z = number.zero;
    State_Enum state = State_Enum.normal;
    System.out.println(z.getValue());
    System.out.println(z);
    System.out.println(number.one);
    switch (z) {
      case zero:
        System.out.println(0);
        break;
      case one:
        System.out.println(1);
        break;
      case two:
        System.out.println("2");
        break;
    }
    //equals
    if (z.equals(number.one)) {
      System.out.println("equal!");
    } else {
      System.out.println("unequal");
    }
    //valueOf
    System.out.println(number.valueOf("zero"));
    //ordinal
    System.out.println(z.ordinal()); //the index of values
    System.out.println(state.toString());
    state = state.ChangeState();
    System.out.println(state.getState());
  }
}

0
zero
one
0
unequal
zero
0
正常
停止