设计一种可绘制各种形状的画笔Painter类，要求用抽象原则，并且具备GUI界面。语言为Java，可绘制的图形为矩形，圆，直线

在Java中，我们可以遵循设计模式中的抽象工厂模式（Abstract Factory Pattern）和装饰者模式（Decorator Pattern），结合Swing或JavaFX等图形用户界面库来创建这个Painter类。这里我会给出一个简化的抽象框架：

import java.awt.*;
import javax.swing.*;

// 抽象画笔接口
public abstract class Painter {
    protected Shape shape;
    
    public Painter(Shape shape) {
        this.shape = shape;
    }
    
    // 绘制抽象方法
    public abstract void draw(Graphics g);
    
    // 获取形状
    public Shape getShape() {
        return shape;
    }
}

// 抽象形状接口
public interface Shape {
    // 设置形状的属性（如矩形的长宽、圆形的半径）
    void setDimensions(double... dimensions);

    // 返回形状的基本描述
    String getDescription();
}

// 具体形状实现，比如Rectangle和Circle
public class Rectangle extends Shape {
    private double width, height;

    @Override
    public void setDimensions(double w, double h) {
        width = w;
        height = h;
    }

    @Override
    public String getDescription() {
        return "Rectangle [" + width + "x" + height + "]";
    }

    @Override
    public void draw(Graphics g) {
        g.fillRect((int)shape.getX(), (int)shape.getY(), (int)width, (int)height);
    }
}

public class Circle extends Shape {
    private double radius;

    @Override
    public void setDimensions(double r) {
        radius = r;
    }

    @Override
    public String getDescription() {
        return "Circle [" + radius + "]";
    }

    @Override
    public void draw(Graphics g) {
        g.drawOval((int)shape.getX(), (int)shape.getY(), (int)(radius*2), (int)(radius*2));
    }
}

// GUI抽象画布类
public abstract class DrawingCanvas extends JPanel {
    protected Painter painter;

    public DrawingCanvas(Painter painter) {
        this.painter = painter;
    }

    public abstract void paintComponent(Graphics g);
}

// 具体画布实现，比如DrawingFrame
public class DrawingFrame extends JFrame implements DrawingCanvas {
    @Override
    protected void paintComponent(Graphics g) {
        super.paintComponent(g);
        painter.draw(g);
    }

    // 添加事件监听器或菜单选项以便选择形状
    public void setPainterShape(Shape newShape) {
        painter = new Painter(newShape);
    }
}