上传文件至 'W5'

W5/Shape.java

@@ -0,0 +1,64 @@
+public abstract class Shape {
+    public abstract double getArea();
+    public abstract void draw();
+}
+class Circle extends Shape {
+    private double radius;
+    public Circle(double radius) {
+        this.radius = radius;
+    }
+    public double getArea() {
+        return Math.PI * radius * radius;
+    }
+    public void draw() {
+        System.out.println("Drawing a circle with radius " + radius);
+    }
+}
+class Rectangle extends Shape {
+    private double width, height;
+    public Rectangle(double width, double height) {
+        this.width = width;
+        this.height = height;
+    }
+    public double getArea() {
+        return width * height;
+    }
+    public void draw() {
+        System.out.println("Drawing a rectangle with width " + width + " and height " + height);
+    }
+}
+class Triangle extends Shape {
+    private double base, height;
+    public Triangle(double base, double height) {
+        this.base = base;
+        this.height = height;
+    }
+    public double getArea() {
+        return 0.5 * base * height;
+    }
+    public void draw() {
+        System.out.println("Drawing a triangle with base " + base + " and height " + height);
+    }
+}
+class ShapeUtil {
+    public static void printArea(Shape shape) {
+        System.out.println("面积：" + shape.getArea());
+    }
+    public static void drawShape(Shape s) {
+        s.draw();
+    }
+}
+class Main {
+    public static void main(String[] args) {
+        Shape circle = new Circle(5);
+        Shape rect = new Rectangle(4, 6);
+        Shape tri = new Triangle(3, 4);
+        ShapeUtil.printArea(circle);
+        ShapeUtil.printArea(rect);
+        ShapeUtil.printArea(tri);
+        System.out.println("\nDrawing shapes:");
+        ShapeUtil.drawShape(circle);
+        ShapeUtil.drawShape(rect);
+        ShapeUtil.drawShape(tri);
+    }
+}