題目1：

創(chuàng)建Person接口(即“人”)，它有setData()和getData()方法對(duì)“人”屬性name、sex和birthday賦值和獲得這些屬性組成的字符串信息。創(chuàng)建類Student實(shí)現(xiàn)Person接口，并對(duì)自己的“學(xué)生”屬性的成員變量sID、speciality設(shè)置值和獲得它們值所組成的字符串信息。

代碼：

People.java(接口)

package?com.interfaces;
public?interface?People?{
public?void?setData(String?name,String?sex,String?birthday);
public?String?getData();
}
Student.java(實(shí)現(xiàn)接口的類)

package?com.interfaces.impl;
?
import?com.interfaces.People;
?
public?class?Student?implements?People?{
	?private?String?name;??
	?private?String?sex;??
	?private?String?birthday;??
	?private?String?sID="2014";??
	?private?String?speciality="寫代碼";??
	@Override
	public?void?setData(String?name,?String?sex,?String?birthday)?{
		//?TODO?Auto-generated?method?stub
???????this.name=name;
???????this.sex=sex;
???????this.birthday=birthday;
	}
?
	@Override
	public?String?getData()?{
		//?TODO?Auto-generated?method?stub
	????return?"名字:?"?+?name?+?",性別:?"?+?sex?+?",生日:?"?+?birthday?+?",ID:?"?+?sID?+?",專長(zhǎng):?"?+speciality;
	}
?
	public?static?void?main(String[]?args)?{
		//?TODO?Auto-generated?method?stub
???????People?Yantai=new?Student();
???????Yantai.setData("海哥",?"男",?"2017年2月19日");
???????System.out.println(Yantai.getData());
???????
	}
?
}

題目2：

編寫程序,求柱體的體積:

（1）、為柱體的底面設(shè)計(jì)一個(gè)接口Geometry，包含計(jì)算面積的方法getArea();

（2）、為柱體設(shè)計(jì)類pillar，要求：

a)有兩個(gè)成員變量，底面和高度。底面是任何可以計(jì)算面積的幾何形狀。

b)實(shí)現(xiàn)構(gòu)造方法，對(duì)成員變量賦值。

c)包含成員方法，計(jì)算柱體pillar的體積。

（3）、編寫測(cè)試類圓形類、矩形類實(shí)現(xiàn)Geometry接口，編寫測(cè)試類Test，分別用圓形、矩形作為柱體的底面，并計(jì)算其體積。

代碼：

Geometry.java(接口)

package?com.interfaces;
public?interface?Geometry?{
public?double?getArea();
}
Test.java(接口實(shí)現(xiàn)類)

package?com.interfaces.impl;
?
import?com.interfaces.Geometry;
?
public?class?Test?{
	public?static?void?main(String[]?args)?{
		//?TODO?Auto-generated?method?stub
		?Pillar?pillar;????
?????????Geometry?bottom;????
????????????????
?????????bottom?=?new?Rect(10,?5);?//接口實(shí)現(xiàn)方法???
?????????pillar?=?new?Pillar(bottom,?5);????
?????????System.out.println("矩形底的柱體的體積："?+?pillar.Volume());????
????????????????
?????????bottom?=?new?Circle(5);?
?????????pillar?=?new?Pillar(bottom,?5);????
?????????System.out.println("圓形底的柱體的體積："?+?pillar.Volume());??
	}
	
	/*
	?*?柱體設(shè)計(jì)類
	?*/
	class?Pillar{
		Geometry?bottom;??
	????double?height;??
	????public?Pillar(Geometry?bottom,?double?height){??
	????????this.bottom=bottom;??
	????????this.height=height;??
	????}??
	????public?double?Volume(){??
	????????return?bottom.getArea()*this.height;???
	????}??
	}
	
	/*
	?*?矩形測(cè)試類
	?*/
	class?Circle?implements?Geometry{
????????double?radius;
		public?Circle(double?radius){??
	????????this.radius?=?radius;??
	????}??
		public?double?getArea()?{
			//?TODO?Auto-generated?method?stub
			return?Math.PI*this.radius*this.radius;
		}
		
	}
	
	/*
	?*?圓形測(cè)試類
	?*/
	class?Rect?implements?Geometry{??
	????double?wide,length;??
	????public?Rect(double?wide,?double?length){??
	????????this.wide?=?wide;??
	????????this.length?=?length;??
	????}??
	????public?double?getArea()?{??
	????????return?wide*length;??
	????}??
	}??
}

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