关于return的用法

public class Box {
    int length,width, height,volume;
    int v;
    public Box(int length, int width, int height) {
        super();
        this.length = length;
        this.width = width;
        this.height = height;
      
    }
    public int getLength() {
        return length;
    }
    public void setLength(int length) {
        this.length = length;
    }
    public int getWidth() {
        return width;
    }
    public void setWidth(int width) {
        this.width = width;
    }
    public int getHeight() {
        return height;
    }
    public void setHeight(int height) {
        this.height = height;
    }
    public int getvolume() {
        return volume;
    }
    public void setvolume(int volume) {
        this.volume = volume;
    }
   
    public int calcVolume(){
         v=length*width*height;
         System.out.println(v);
         return v;
      
        }
    public void print(){
        System.out.println(v);
    }
    public static void main(String[] args) {
    Box box=new Box(10,15,12);
    box.print();
    box.calcVolume();
    }

}