Java语言程序设计 上机实验4 掌握声明接口、一个类实现接口的声明和使用方法

Cylinder.Java
package one;

public class Cylinder extends Ellipse implements IVolume{

    /**
     * @param args
     */
    int high;
    Cylinder(){
        this.high=6;
    }
    public double Volume(){
        return radius_a*radius_b*3.14*high;
    }
    public double Area(){
        return radius_a*radius_b*3.14*2+high*Perimeter();
    }
    public static void main(String[] args) {
        // TODO Auto-generated method stub
        IVolume A=new Cylinder();
        IVolume V=new Cylinder();
        System.out.println("表面积是"+A.Area());
        System.out.println("体积是"+V.Volume());
    }

}
Ellipse.java
package one;

public class Ellipse implements IPerimeter,IArea{ //椭圆类
    protected double radius_a; //a轴半径
    protected double radius_b; //b轴半径
    public Ellipse(double radius_a) { //构造方法
        this.radius_a = radius_a;
    }
    public Ellipse(double radius_a, double radius_b) { //构造方法
        this.radius_a = radius_a; this.radius_b = radius_b;
    }
    public Ellipse() { this(4,4); }
    public String toString() {
        return "a轴半径"+this.radius_a+"，b轴半径"+this.radius_b;
    }
    public double Area() { //计算椭圆面积，覆盖父类的抽象方法
        return Math.PI*this.radius_a*this.radius_b;
    }
    public double Perimeter(){ //计算椭圆周长，覆盖父类的抽象方法
        return Math.PI*(this.radius_a+this.radius_b);
    }
}

IArea.java
package one;

public interface IArea {
    public double Area();
}

IPerimeter.java
package one;


public interface IPerimeter {
    public double Perimeter();
}

IVolume.java
package one;

public interface IVolume {
    public double Volume();
    public double Area();
}


二．
package two;
import java.util.Arrays;
public class Q2 {
    
    public static void main(String[] args) {
        // TODO Auto-generated method stub
        String[] a=new String[20];
        String b=new String();
        String c=new String();
        b="g";
        a[0]="a";a[1]="b";a[2]="c";a[3]="d";a[4]="e";a[5]="f";a[6]="g";a[7]="h";
        a[8]="i";a[9]="j";a[10]="k";a[11]="l";a[12]="m";a[13]="n";a[14]="o";
        for(int i=0;i<15;i++){
            for(int j=i+1;j<15;j++){
                if(a[i].compareTo(a[j])>0){
                    c=a[i];
                    a[i]=a[j];
                    a[j]=c;
                }
            }
        }
        if(sxcz(b,a)){
            System.out.println("顺序查找法已查找到");
        }
        else{
            System.out.println("顺序查找未找到");
        }
        if(efcz(b,a)){
            System.out.println("二分法查找法已查找到");
        }
        else{
            System.out.println("二分法查找未找到");
        }
    }
    public static boolean sxcz(String b,String[] a){
        for(int i=0;i<20;i++){
            if(b==a[i]){
                return true;
            }
        }
        return false;
    }
    public static boolean efcz(String b,String[] a){
        int front=0;
        int end=14;
        int mid=7;
        for(;end>=front;){
            if(a[mid]==b)
                return true;
            else if(a[mid].compareTo(b)>0){
                end=mid-1;
                mid=(mid+front)/2;
            }
            else{ 
                front=mid+1;
                mid=(front+end)/2;
            }
        }
        return false;
    }
}