Java 创建 class 的数组列表并调用 class 的方法

Question

到目前为止，我正在尝试创建一个 ArrayList 个对象，这些对象共享我想按 ArrayList.

顺序调用的相同方法

到目前为止代码是这样的

public class Shape extends Application {
   public void do(GraphicsContext canvas, int size, Color color){
     ;
   } 
}


public class Triangle extends Shape {
   @Override
   public void do(GraphicsContext canvas, int size, Color color){
      canvas.setFill(Color.WHITE);
      double[] xs = {60,80.0,50.0};
      double[] ys = {60,120.0,50.0};
      canvas.fillPolygon(xs,ys,3);
   }
}

而自动启动的主要 Class 是这样的

public class Main {
    public void drawForegroundContent(GraphicContext canvas){
       ArrayList<Shape> shpes = new ArrayList<Shape>();
       Triangle t = new Triangle();
       shapes.add(t);
       shapes.add(t);

       for (Shape k : shapes){
          k.do(canvas,CoreColor.BLACK, 80);
       }
    }
}

然而错误是<identifier> expected k.do(canvas, CoreColor.BLACK, 80)

此外，它对 Shape-class 的 void do 上的标识符有类似的抱怨。这段代码到底有什么问题？

Answer 1

根据 docs, do is a keyword (As in the context of a do-while loop). You need to name your method something else. As the JLS 关于关键字的说法：

50 character sequences, formed from ASCII letters, are reserved for use as keywords and cannot be used as identifiers

另请注意，调用该方法时参数顺序不正确。当方法接受 GraphicContext、int、Color 时，您正在传递 GraphicContext、Color、int。

Java 创建 class 的数组列表并调用 class 的方法

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