830
京東網上商城
jdk1.5新特性5之枚舉之模擬枚舉類型
模擬方式一
package cn.xy.Enum;
public class TrafficLampEasy
{
private int time;
public final static TrafficLampEasy REDLAMP = new TrafficLampEasy(20);
public final static TrafficLampEasy GREENLAMP = new TrafficLampEasy(20);
public final static TrafficLampEasy YELLOWLAMP = new TrafficLampEasy(5);
public TrafficLampEasy()
{
}
public TrafficLampEasy(int time)
{
this.time = time;
}
public TrafficLampEasy nextLamp()
{
TrafficLampEasy result = new TrafficLampEasy();
if (this == REDLAMP)
{
result = GREENLAMP;
}
else if (this == GREENLAMP)
{
result = YELLOWLAMP;
}
else if (this == YELLOWLAMP)
{
result = REDLAMP;
}
return result;
}
public String getValue()
{
String result = "";
if (this == REDLAMP)
{
result = "紅燈,時長:" + time;
}
else if (this == GREENLAMP)
{
result = "綠燈,時長:" + time;
}
else if (this == YELLOWLAMP)
{
result = "黃燈,時長:" + time;
}
return result;
}
public int getTime()
{
return time;
}
public void setTime(int time)
{
this.time = time;
}
}
TrafficLampEasy teRed = TrafficLampEasy.REDLAMP;
System.out.println(teRed.getValue());
System.out.println(teRed.nextLamp().getValue());
從這個例子中我們看出，枚舉類型其實就是一個類返回該類本身
模擬方式二
package cn.xy.Enum;
public abstract class TrafficLamp
{
/**
* 下一個燈
*/
public abstract TrafficLamp nextLamp();
/**
* 獲取值
*/
public abstract String getValue();
/**
* 時長
*/
private int time;
public TrafficLamp()
{
}
public TrafficLamp(int time)
{
this.time = time;
}
/**
* 紅燈，匿名類，相當於繼承TrafficLamp抽象類，並實現抽象方法
*/
public final static TrafficLamp REDLAMP = new TrafficLamp(50) {
@Override
public TrafficLamp nextLamp()
{
return GREENLAMP;
}
@Override
public String getValue()
{
return "紅燈,時長:" + this.getTime();
}
};
public final static TrafficLamp GREENLAMP = new TrafficLamp(50) {
@Override
public TrafficLamp nextLamp()
{
return YELLOWLAMP;
}
@Override
public String getValue()
{
return "綠燈,時長:" + this.getTime();
}
};
public final static TrafficLamp YELLOWLAMP = new TrafficLamp(2) {
@Override
public TrafficLamp nextLamp()
{
return REDLAMP;
}
@Override
public String getValue()
{
return "黃燈,時長:" + this.getTime();
}
};
public int getTime()
{
return time;
}
public void setTime(int time)
{
this.time = time;
}
}
TrafficLamp red = TrafficLamp.REDLAMP;
System.out.println(red.getValue());
System.out.println(red.nextLamp().getValue());
采用匿名類的方式，那麼什麼是匿名類呢？
匿名類適合那些隻需要使用一次的類
public abstract class AnonymousClassDesk
{
public abstract double getPrice();
public abstract String getName();
}
public class Desk extends AnonymousClassDesk
{
@Override
public double getPrice()
{
return 100;
}
@Override
public String getName()
{
return "普通書桌";
}
}
public static void main(String[] args)
{
AnonymousClassDesk desk = new AnonymousClassDesk() {
@Override
public double getPrice()
{
return 100;
}
@Override
public String getName()
{
return "匿名書桌";
}
};
System.out.println(desk.getName());
}
不僅可以使抽象類，也可以是接口。匿名類沒有什麼特別的地方，同樣還是要實現需要實現的方法。
最後更新：2017-04-04 07:32:09