public    interface Icolor{

       int apply(int x,int y);

    }

 public enum color implements Icolor{

     plus("+"){

        public int apply(int x,int y){ return x+y;}

     },

     min("-"){

        public int apply(int x,int y){ return x-y;}

     }

     ;

          private final String num;

          color(String num){

              this.num=num;

          }

     }

//调用 color.plus.apply(100, 1)