将JTextPane绘制到BufferedImage时错误对齐

Question

我正在尝试将一些样式化的文本绘制到缓冲图像中。我使用的JTextPane不属于任何视图层次结构。我使用所需的对齐方式设置文档属性，但结果未正确对齐。更糟糕的是，当我再次运行相同的测试时，我会得到不同字体大小的不同结果，有时甚至会得到不同的结果。

下图显示了结果。段落应该是从上到下，对齐左，中，右，全。红框是JTextPane边框。亲自看看。

因为我是一个新的stackoverflow用户，所以它不允许我发布图像。您可以在http://www.sendtoprint.net/preview/textfile.jpg

看到图片

这是在Java 1.7上完成的，但也发生在1.6中。代码：

public void createBufferedImage ()
    {
    try
        {
        BufferedImage bi = new BufferedImage (1000, 1200, BufferedImage.TYPE_INT_RGB);
        Graphics2D gg = bi.createGraphics ();

        gg.setRenderingHint (RenderingHints.KEY_TEXT_ANTIALIASING, RenderingHints.VALUE_TEXT_ANTIALIAS_ON);
        gg.setRenderingHint (RenderingHints.KEY_FRACTIONALMETRICS, RenderingHints.VALUE_FRACTIONALMETRICS_ON);

        gg.setBackground (Color.white);
        gg.fillRect (0, 0, bi.getWidth (), bi.getHeight ());

        gg.scale (3.0f, 3.0f);
        gg.translate (16, 16);

        String text = "The residents of Colorado and Washington state have voted to legalize "
                + "the recreational use of marijuana, and all hell is about to break "
                + "loose -- at least ideologically. The problem is that pot is still very much "
                + "illegal under federal law, and the Obama administration must decide whether "
                + "to enforce federal law in a state that has rejected the substance of that law."
                + "\n\n";


        DefaultStyledDocument doc = new DefaultStyledDocument ();

        MutableAttributeSet attr = new SimpleAttributeSet ();
        StyleConstants.setFontFamily (attr, "Arial");
        StyleConstants.setFontSize (attr, 9);
        StyleConstants.setForeground (attr, Color.black);

        MutableAttributeSet parAttr = new SimpleAttributeSet ();

        doc.insertString (0, text, attr);

        StyleConstants.setAlignment (parAttr, StyleConstants.ALIGN_LEFT);
        doc.setParagraphAttributes (0, doc.getLength (), parAttr, false);

        doc.insertString (doc.getLength (), text, attr);

        StyleConstants.setAlignment (parAttr, StyleConstants.ALIGN_CENTER);
        doc.setParagraphAttributes (doc.getLength () - text.length (), text.length (), parAttr, false);

        doc.insertString (doc.getLength (), text, attr);

        StyleConstants.setAlignment (parAttr, StyleConstants.ALIGN_RIGHT);
        doc.setParagraphAttributes (doc.getLength () - text.length (), text.length (), parAttr, false);

        doc.insertString (doc.getLength (), text, attr);

        StyleConstants.setAlignment (parAttr, StyleConstants.ALIGN_JUSTIFIED);
        doc.setParagraphAttributes (doc.getLength () - text.length (), text.length (), parAttr, false);

        JTextPane tc = new JTextPane ();
        tc.setBorder (BorderFactory.createLineBorder (Color.red, 1));
        tc.setDocument (doc);
        tc.setBackground (Color.white);
        tc.setLocation (0, 0);
        tc.setSize (new Dimension (300, 370));
        tc.paint (gg);

        System.out.println ("Writing file: " + new Date ().toString ());

        File file = new File ("C:\\Users\\Yishai\\Desktop\\text\\file.jpg");
        ImageIO.write (bi, "jpg", file);
        }
    catch (Exception e)
        {
        System.out.println (e.getMessage ());
        }
    }   

任何想法我能做些什么不同的事情？有没有JTextPane设置？文本缓存？什么？

感谢。