如何使用 Apache Batik 库在 SVGGraphics2D 中转换 Graphics2D？

Question

我需要将 JPanel（图形）中的内容（形状）转换为 SVGGraphics2D 对象，以获取使用 Apache Batik 库生成的 svg 文件。

public void paintComponent(Graphics g) {

    Graphics2D g2 = (Graphics2D) g;

    g2.setRenderingHint(RenderingHints.KEY_ANTIALIASING, 

            RenderingHints.VALUE_ANTIALIAS_ON);

    g2.setPaint(fg);

    // draw Text

    g2.drawString("Hello world!", 250, 400);

    // draw Line2D.Double

    g2.setPaint(orange);

    g2.draw(new Line2D.Double(50, 50, 200, 200));

    // draw Point2D.Double

    g2.setPaint(red);

    g2.fill(new Ellipse2D.Double(400, 400, 5, 5));

    // draw Rectangle2D.Double

    g2.setPaint(magenta);

    g2.draw(new Rectangle2D.Double(600, 600, 300, 150));

    g2.setPaint(magenta);

    g2.draw(new Rectangle2D.Double(300, 300, 300, 150));

    // draw Ellipse2D.Double

    g2.setPaint(blue);

    g2.draw(new Ellipse2D.Double(400, 400, 200, 200));

    // draw GeneralPath (polygon)

    g2.setPaint(green);

    int x1Points[] = {200, 500, 300};

    int y1Points[] = {100, 100, 300};

    GeneralPath polygon = new GeneralPath(GeneralPath.WIND_EVEN_ODD, 

            x1Points.length);

    polygon.moveTo(x1Points[0], y1Points[0]);

    for ( int index = 1; index < x1Points.length; index++ ) {

        polygon.lineTo(x1Points[index], y1Points[index]);

    }

    polygon.closePath();

    g2.draw(polygon);

}

public void onlyWrite(){

    JFrame f = new JFrame("Shapes Example2");

    f.addWindowListener(new WindowAdapter() {

        public void windowClosing(WindowEvent e) {System.exit(0);}

    });

    // Get a DOMImplementation.

    DOMImplementation domImpl = GenericDOMImplementation.getDOMImplementation();

铸造 SVGGraphics2D 我得到以下异常：

线程“main”中的异常 java.lang.ClassCastException: sun.java2d.SunGraphics2D 无法在 ShapesExample2.onlyWrite(ShapesExample2.java:122) at ShapesExample2.main(ShapesExample2.java: 144)

我怎样才能得到 svg 文件？谢谢！

Answer 1

反过来试试，SVGGraphics2D是 的子类Graphics2D，Graphics2D不是 的子类SVGGraphics2D。因此，只需将 SVG 图形对象传递给组件的 paint 方法即可。pane.paintComponent(svgGenerator);您可以在此处查看更多示例：Apache Batik SVG 生成器