Java的构造函数如何在主函数里调用问题！求大神帮忙！万分感谢！

//矩形类
public class Juxing {
//长和宽要私有化
private int length;
private int width;

//构造方法
public Juxing(int length, int width) {
this.length = length;
this.width = width;
}

//返回矩形的面积
public int area() {
return length*width;
}

public static void main(String[] args) {

Juxing AA = new Juxing(10, 5);
System.out.println(AA.area());
}
}

构造函数这样写：

public Juxing(int a,int b)
{
    length=a;
    wide=b;
}

主函数里初始化可以这样：

Juxing AA = new Juxing(4,5);

百度你就全会了