Java第四次作业

1编写“电费管理类”及其测试类

public class ElectricityManagement {
   private int Lastmonthmeterreading;
   private int Themonthmeterreading;
   
   public ElectricityManagement(){
       
   }
   public  ElectricityManagement(int Lastmonthmeterreading,int Themonthmeterreading ) {
       this.Lastmonthmeterreading=Lastmonthmeterreading;
       this.Themonthmeterreading=Themonthmeterreading;
   }
   //获取上月电表读数
   public int getLastmonthmeterreading() {
       return Lastmonthmeterreading;
   }
   //设置上月电表读数
   public void setLastmonthmeterreading(int Lastmonthmeterreading) {
         if(Lastmonthmeterreading<0) {//电表读数不能为负数
             this.Lastmonthmeterreading=0;
         }
         else {
             this.Lastmonthmeterreading=Lastmonthmeterreading;
         }
   }
   //获取本月电表读数
   public int getThemonthmeterreading() {
       return Themonthmeterreading;
   }
   //设置本月电表读数
   public void setThemonthmeterreading(int Themonthmeterreading) {
     if(Themonthmeterreading<0) {//电表读数不能为负数
         this.Themonthmeterreading=0;
     }
     else {
         this.Themonthmeterreading=Themonthmeterreading;
     }
   }
}
   public class TestElectricityManagement{
       public static void main(String[]args) {
           ElectricityManagement e1=new ElectricityManagement(30,48);
           e1.addThemonthmeterreading();
           e1.printMessage();
           
           ElectricityManagement e2=new ElectricityManagement(60,28); 
           e2.addLastmonthmeterreading();
           e2.printMessage();
       }
       
   
       
   }

2：编写圆柱体类及其测试类
public class cylindrical extends round{
private double height;
private double voluem;

public void setHeight(double height){ //设置圆柱体的高
this.height = height;
}
public double getVoluem() { //求圆柱体的体积，半径继承自圆的类，不用重复定义
return 3.14*radius*radius*height;
}
}

ppublic class circle { public static void main(String[] args) {

Scanner sc=new Scanner(System.in); 
int r,h;
 double PI=3.14; 
System.out.println("请输入半径："); 
System.out.println("请输入高：");
 r=sc.nextInt(); h=sc.nextInt(); 
System.out.println("底面积为"+PI*r*r); 
System.out.println("体积为"+PI*r*r*h);
 } 

好吧，其实有些程序运行不出来，有错误。