用法一：常量；
public enum Color {
RED, GREEN, BLANK, YELLOW
}
用法二：duswitch；
enum Signal {
GREEN, YELLOW, RED
}
public class TrafficLight {
Signal color = Signal.RED;
public void change() {
switch (color) {
case RED:
color = Signal.GREEN;
break;
case YELLOW:
color = Signal.RED;
break;
case GREEN:
color = Signal.YELLOW;
break;
}
}
}
用法三：向枚举中添加新方法；
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) {
this.name = name;
this.index = index;
}
// 普通方法
public static String getName(int index) {
for (Color c : Color.values()) {
if (c.getIndex() == index) {
return c.name;
}
}
return null;
}
// get set 方法
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public int getIndex() {
return index;
}
public void setIndex(int index) {
this.index = index;
}
}
用法四：覆盖枚举的方法；
public class Test {
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) {
this.name = name;
this.index = index;
}
// 覆盖方法
@Override
public String toString() {
return this.index + "_" + this.name;
}
}
public static void main(String[] args) {
System.out.println(Color.RED.toString());
}
}
用法五：实现接口；
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) {
this.name = name;
this.index = index;
}
// 接口方法
@Override
public String getInfo() {
return this.name;
}
// 接口方法
@Override
public void print() {
System.out.println(this.index + ":" + this.name);
}
}
用法六：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
}
}