使用组合和继承在 Java 中绘制图片

Question

这是我第一次 post 来这里。我是一名在高中学习 AP 计算机科学的学生。对于一个项目，我必须画一张篮球的图片。好的，很简单。问题是我必须使用正确的组合和继承来做到这一点。我总不能在主class里扔一堆图形方法吧。我已经记下了所有基本代码，但这是我需要帮助的...

我希望 class Basketball 继承 super-class Circle 的所有内容。我是否通过在 class Basketball 标题中扩展 class Circle 来正确地做到这一点？
在classBasketball里面，我如何link到class行和classAirValve才能显示正确的构图？

如您所见，我理解这些概念，但我不明白如何让它们很好地发生。

import java.awt.*;
import java.applet.*;
import java.util.*;
import java.awt.Color;
import java.awt.Graphics;


/* The point of this lab is to draw a basketball using one example of
 * proper inheritance and two examples of proper composition. 
 */



public class Basketball extends Circle
{
public static void main(String[] args)
{
   Lines line = new Lines();
   AirValve airvalve = new AirValve();
}

}

class Lines
{

public Lines()
{

}

public void paintLine(Graphics g)
{
    g.drawArc(300, 275, 200, 275, 295, 135); //left arc
    g.drawLine(650, 150, 650, 650); //middle line
    g.drawLine(400, 400, 900, 400); //cross line
    g.drawArc(800, 275, 200, 275, 245, -135); //right arc
}

}

class Circle
{

public Circle()
{

}

public void paintCirc(Graphics g)
{
    g.setColor(Color.orange);
    g.fillOval(400, 150, 500, 500);
}

}

class AirValve
{

public AirValve()
{

}

public void paintAV(Graphics g)
{
    g.setColor(Color.black);
    g.fillOval(645, 625, 10, 10);
}

}

Answer 1

继承：

public class Circle extends JComponent {
  //draws a circle
  public void paintComponent(Graphics g) {
   //...
  }
}

public class Basketball extends Circle {
  //draws a basketball
  public void paintComponent(Graphics g) {
   super.paintComponent(g); // this will draw the circle outline of your basketball
   //draw the middle
  }
}

组成：

//draws a circle
public static void drawCircle(Graphics g, int x, int y) {
}

//draws a cross
public static void drawCircle(Graphics g, int x, int y) {
}

//draws a basketball
public static void drawBasketball(Graphics g, int x, int y) {
  drawCircle(g, x, y);
  drawCross(g, x, y);
}

使用组合和继承在 Java 中绘制图片

Drawing a picture in Java using composition and inheritance

java

inheritance

composition