public enum Color { 
  RED, GREEN, BLANK, YELLOW 
 } 

 enum Signal { 
   GREEN, YELLOW, RED 
 } 
 public class TrafficLight { 
   Signal color = SignalRED; 
   public void change() { 
     switch (color) { 
     case RED: 
       color = SignalGREEN; 
       break; 
     case YELLOW: 
       color = SignalRED; 
       break; 
     case GREEN: 
       color = SignalYELLOW; 
       break; 
     } 
   } 
 } 

 public enum Color { 
   RED("红色", 1), GREEN("绿色", 2), BLANK("白色", 3), YELLO("黄色", 4); 
   // 成员变量 
   private String name; 
   private int index; 
   // 构造方法 
   private Color(String name, int index) { 
     thisname = name; 
     thisindex = index; 
   } 
   // 普通方法 
   public static String getName(int index) { 
     for (Color c : Colorvalues()) { 
       if (cgetIndex() == index) { 
         return cname; 
       } 
     } 
     return null; 
   } 
   // get set 方法 
   public String getName() { 
     return name; 
   } 
   public void setName(String name) { 
     thisname = name; 
   } 
   public int getIndex() { 
     return index; 
   } 
   public void setIndex(int index) { 
     thisindex = index; 
   } 
 } 

 public enum Color { 
   RED("红色", 1), GREEN("绿色", 2), BLANK("白色", 3), YELLO("黄色", 4); 
   // 成员变量 
   private String name; 
   private int index; 
   // 构造方法 
   private Color(String name, int index) { 
     thisname = name; 
     thisindex = index; 
   } 
   //覆盖方法 
   @Override 
   public String toString() { 
     return thisindex+"_"+thisname; 
   } 
 } 

 public interface Behaviour { 
   void print(); 
   String getInfo(); 
 } 
 public enum Color implements Behaviour{ 
   RED("红色", 1), GREEN("绿色", 2), BLANK("白色", 3), YELLO("黄色", 4); 
   // 成员变量 
   private String name; 
   private int index; 
   // 构造方法 
   private Color(String name, int index) { 
     thisname = name; 
     thisindex = index; 
   } 
 //接口方法 
   @Override 
   public String getInfo() { 
     return thisname; 
   } 
   //接口方法 
   @Override 
   public void print() { 
     Systemoutprintln(thisindex+":"+thisname); 
   } 
 } 

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