我正在使用 flysaucer 将 HTML 渲染为图像,使用 Java2DRenderer:
Map<Key,Object> renderingHints = new HashMap<Key,Object>();
renderingHints.put(RenderingHints.KEY_INTERPOLATION, RenderingHints.VALUE_INTERPOLATION_BICUBIC);
renderingHints.put(RenderingHints.KEY_RENDERING, RenderingHints.VALUE_RENDER_QUALITY);
renderingHints.put(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);
renderingHints.put(RenderingHints.KEY_DITHERING, RenderingHints.VALUE_DITHER_DISABLE);
hints = new RenderingHints(renderingHints);
Java2DRenderer renderer = new Java2DRenderer(dom, width, height);
renderer.setRenderingHints(renderingHints);
renderer.getSharedContext().setDPI(DPI);
renderer.setBufferedImageType(BufferedImage.TYPE_INT_ARGB);
img = renderer.getImage();
然后我将渲染的图像添加到 PDF 文档中,将其缩放以适合整个页面。
com.lowagie.text.Document pdf = new com.lowagie.text.Document(isLandscape ? PageSize.A4.rotate() : PageSize.A4);
pdf.setMargins(MARGIN, MARGIN, MARGIN, MARGIN);
Rectangle ps = pdf.getPageSize();
PdfWriter.getInstance(pdf, outputStream);
pdf.open();
com.lowagie.text.Image pdfImage = com.lowagie.text.Image.getInstance(img, null);
pdfImage.scaleAbsolute(
ps.getWidth() - pdf.leftMargin() - pdf.rightMargin(),
ps.getHeight() - pdf.topMargin() - pdf.bottomMargin()
);
pdf.add(pdfImage);
pdf.close();
问题是 FS 呈现的图像背景颜色为纯白色......所以打印机用非常浅的灰色填充整个页面(我相信缩放会将纯白色转换为浅灰色)。
如何强制飞碟生成透明图像,这样我就可以避免这个问题?