JAVA_SE 枚举类

 

 

public class testseason {
	public static void main(string[] args) {
		season spring = season.spring;
		system.out.println(spring);
		spring.show();
		system.out.println(spring.getseasonname());
	}
}
//枚举类
class season{
	//1.提供类的属性，声明为private final 
	private final string seasonname;
	private final string seasondesc;
	//2.声明为final的属性，在构造器中初始化。
	private season(string seasonname,string seasondesc){
		this.seasonname = seasonname;
		this.seasondesc = seasondesc;
	}
	//3.通过公共的方法来调用属性
	public string getseasonname() {
		return seasonname;
	}
	public string getseasondesc() {
		return seasondesc;
	}
	//4.创建枚举类的对象:将类的对象声明public static final
	public static final season spring = new season("spring", "春暖花开");
	public static final season summer = new season("summer", "夏日炎炎");
	public static final season autumn = new season("autumn", "秋高气爽");
	public static final season winter = new season("winter", "白雪皑皑");
	@override
	public string tostring() {
		return "season [seasonname=" + seasonname + ", seasondesc="
				+ seasondesc + "]";
	}
	public void show(){
		system.out.println("这是一个季节");
	}
}

　　

jdk5 enum关键字创建枚举类

/*
 * 一、枚举类
 * 1.如何自定义枚举类
 * 2.如何使用enum关键字定义枚举类
 *     >常用的方法:values() valueof(string name)
 *     >如何让枚举类实现接口:可以让不同的枚举类的对象调用被重写的抽象方法，执行的效果不同。（相当于让每个对象重写抽象方法）
 */
public class testseason1 {
	public static void main(string[] args) {
		season1 spring = season1.spring;
		system.out.println(spring);
		spring.show();
		system.out.println(spring.getseasonname());
		
		system.out.println();
		//1.values()
		season1[] seasons = season1.values();
		for(int i = 0;i < seasons.length;i++){
			system.out.println(seasons[i]);
		}
		//2.valueof(string name):要求传入的形参name是枚举类对象的名字。
		//否则，报java.lang.illegalargumentexception异常
		string str = "winter";
		season1 sea = season1.valueof(str);
		system.out.println(sea);
		system.out.println();
		
		thread.state[] states = thread.state.values();
		for(int i = 0;i < states.length;i++){
			system.out.println(states[i]);
		}
		sea.show();
		
	}
}
interface info{
	void show();
}
//枚举类
enum season1 implements info{
	spring("spring", "春暖花开"){
		public void show(){
			system.out.println("春天在哪里？");
		}
	},
	summer("summer", "夏日炎炎"){
		public void show(){
			system.out.println("生如夏花");
		}
	},
	autumn("autumn", "秋高气爽"){
		public void show(){
			system.out.println("秋天是用来分手的季节");
		}
	},
	winter("winter", "白雪皑皑"){
		public void show(){
			system.out.println("冬天里的一把火");
		}
	};
	
	private final string seasonname;
	private final string seasondesc;
	
	private season1(string seasonname,string seasondesc){
		this.seasonname = seasonname;
		this.seasondesc = seasondesc;
	}
	public string getseasonname() {
		return seasonname;
	}
	public string getseasondesc() {
		return seasondesc;
	}
	
	@override
	public string tostring() {
		return "season [seasonname=" + seasonname + ", seasondesc="
				+ seasondesc + "]";
	}
//	public void show(){
//		system.out.println("这是一个季节");
//	}
}

　　

 

1. new 枚举类时，需要进行简写

2. 枚举类可以直接继承接口，与java 正常类一样。并且可以对单独的枚举类重写方法。

 

3. 主要方法

values()方法：返回枚举类型的对象数组。该方法可以很方便地遍历所有的枚举值。
valueof(string str)：可以把一个字符串转为对应的枚举类对象。要求字符串必须是枚举类对象的“名字”。如不是，会有运行时异常。

int	ordinal()           返回枚举常量的序数（它在枚举声明中的位置，其中初始常量序数为零）。