java练习---12

public class L1106 {

    public static void main(String[] args) {
        // TODO Auto-generated method stub
        TestDemo circle1 = new TestDemo();
        double area=circle1.getArea();
        System.out.println(area);
        TestDemo circle2=new TestDemo(10);
        System.out.println(circle2.getArea());
        System.out.println(circle1.getPerimeter());
        System.out.println(circle2.getPerimeter());
        double ridius=10;
        double areaCircle=Math.PI*ridius*ridius;
        System.out.println(areaCircle);
        circle2.setRadius(5);
        System.out.println(circle2.getArea());
    }

}

public class TestDemo {

private double radius;
    
    public TestDemo(double radius) {
        this.radius = radius;
    }
    public TestDemo() {
        this.radius = 1.0;
    }
    public double getArea() {
        return Math.PI * radius * radius;
    }
    public double getPerimeter() {
        return 2 * Math.PI * radius;
    }
    public void setRadius(double newRadius) {
        this.radius = newRadius;
    }
}

package cn.TV;
import java.util.Scanner;
public class L {
    public int channel = 1;
    public int volume = 50;
    public boolean power = false;
    
    public void powerOn() {
        power = true;
        System.out.println("欢迎使用LLTV,电视机已启动！");
    }
    public void powerOff() {
        power = false;
        System.out.println("Loading...");
        System.out.println("**关机**");
    }
    public int getChannel() {
        return channel;
    }
    public void setChannel(int channel) {
        if(power) {
            if(channel >= 1 && channel <= 100) {
                this.channel = channel;
                System.out.println("正在收看LLTV：" + channel );
            }else {
                System.out.println("您并未购买此频道信号！");
            }
        }else {
            System.out.println("请检查您的电视信号接收线是否正常！");
        }
    }
    public void channelUp() {
        if(power  && channel < 100)
            channel++;
        else System.out.println("+++无信号+++");
    }
    public void channelDown() {
        if(power  && channel > 1)
            channel--;
        else System.out.println("---无信号---");
    }
    public void volumeUp() {
        if(power && volume < 100) {
            volume++;
            System.out.println("当前音量为：" + volume + "%！");
        }else System.out.println("音量已达最大值");
    }
    public void volumeDown() {
        if(power && volume > 0) {
            volume--;
            if(volume == 0)
                System.out.println("电视机已静音！");
        }
            
    }
    public static void main(String[] args) {
        // TODO Auto-generated method stub
        Scanner input = new Scanner(System.in);
        L lltv = new L();
        lltv.powerOn();
        System.out.print("手动输入频道序号：");
        int temp = Integer.valueOf(input.nextLine());;
        lltv.setChannel(temp);
        lltv.getChannel();
        lltv.volumeUp();
        lltv.volumeDown();
    }
}