帮我调试一下 输出一个结果

问题遇到的现象和发生背景

我的代码无法输出结果，它可以运行

用代码块功能插入代码，请勿粘贴截图

import java.util.Set;

class changfangxing{
    protected int chang;
    protected int kuan;

public int getChang() {
    return chang;
}
public void setChang(int chang) {
    this.chang = chang;
}
public int getKuan() {
    return kuan;
}
public void setKuan(int kuan) {
    this.kuan = kuan;
}
public int getArea(){
    return this.chang*this.kuan;
}

}

class zhengfangxing extends changfangxing{
    public void setChang(int width){
        this.chang=width;
        this.kuan=width;

    }
    public void setKuan(int width){
        this.chang=width;
        this.kuan=width;
    }
   
}




public class Area {
    public static void main(String[]args){
        changfangxing chang1=new changfangxing();
        chang1.setChang(4);
        chang1.setKuan(5);
        chang1.getArea();

        chang1=new zhengfangxing();
        chang1.setChang(4);
        chang1.setKuan(5);
        chang1.getArea();
        
    }

}

运行结果及报错内容

无结果

我想要达到的结果

怎么让它能输出结果呢？

你不写怎么会有输出呢？？

public class Area {
    public static void main(String[]args){
        changfangxing chang1=new changfangxing();
        chang1.setChang(4);
        chang1.setKuan(5);
        int area1 = chang1.getArea();
        System.out.println("长方形的面积：" + area1);

        chang1=new zhengfangxing();
        chang1.setChang(4);
        chang1.setKuan(5);
        int area2 = chang1.getArea();
        System.out.println("正方形的面积：" + area2);
    }

}

public static void main(String[]args){
        changfangxing chang1=new changfangxing();
        chang1.setChang(4);
        chang1.setKuan(5);
        System.out.println(chang1.getArea());
 
        chang1=new zhengfangxing();
        chang1.setChang(4);
        chang1.setKuan(5);
       System.out.println(chang1.getArea());
        
    }