感谢Epaga的提示和网上的一些示例（查找起来并不那么明显！我主要使用Break
Line作为文本布局），我可以制作一个组件来显示包装的文本。它是不完整的，但至少可以显示预期的效果。

class TextContainer extends JPanel
{
    private int m_width;
    private int m_height;
    private String m_text;
    private AttributedCharacterIterator m_iterator;
    private int m_start;
    private int m_end;

    public TextContainer(String text, int width, int height)
    {
        m_text = text;
        m_width = width;
        m_height = height;

        AttributedString styledText = new AttributedString(text);
        m_iterator = styledText.getIterator();
        m_start = m_iterator.getBeginIndex();
        m_end = m_iterator.getEndIndex();
    }

    public String getText()
    {
        return m_text;
    }

    public Dimension getPreferredSize()
    {
        return new Dimension(m_width, m_height);
    }

    public void paint(Graphics g)
    {
        super.paintComponent(g);

        Graphics2D g2 = (Graphics2D) g;
        FontRenderContext frc = g2.getFontRenderContext();

        LineBreakMeasurer measurer = new LineBreakMeasurer(m_iterator, frc);
        measurer.setPosition(m_start);

        float x = 0, y = 0;
        while (measurer.getPosition() < m_end)
        {
            TextLayout layout = measurer.nextLayout(m_width);

            y += layout.getAscent();
            float dx = layout.isLeftToRight() ?
                    0 : m_width - layout.getAdvance();

            layout.draw(g2, x + dx, y);
            y += layout.getDescent() + layout.getLeading();
        }
    }
}

只是为了好玩，我使它适合一个圆圈（看起来很不合理）：

public void paint(Graphics g)
{
    super.paintComponent(g);

    Graphics2D g2 = (Graphics2D) g;
    FontRenderContext frc = g2.getFontRenderContext();

    LineBreakMeasurer measurer = new LineBreakMeasurer(m_iterator, frc);
    measurer.setPosition(m_start);

    float y = 0;
    while (measurer.getPosition() < m_end)
    {
        double ix = Math.sqrt((m_width / 2 - y) * y);
        float x = m_width / 2.0F - (float) ix;
        int width = (int) ix * 2;

        TextLayout layout = measurer.nextLayout(width);

        y += layout.getAscent();
        float dx = layout.isLeftToRight() ?
                0 : width - layout.getAdvance();

        layout.draw(g2, x + dx, y);
        y += layout.getDescent() + layout.getLeading();
    }
}

我对dx计算不太确定。