java - Apache FOP 设置动态 DPI

Question

我想 Apache FOP 2.3 将 XML+XSL 转换为 PNG 图像。我希望能够为每个图像动态设置 DPI。下面，我有一个工作示例，我通过 FOUserAgent 设置 dpi。我的问题是：这是通过 Apache FOP 设置 DPI 的传统方式吗？或者它必须以不同的方式设置？

public OutputStream transformXSL2Image(String xmlString, String xslString, String docsPerPage, String defaultTransformer, String startPackCount, String totalPackCount, int dpi) throws Exception {
        
        File file = new File("out.png");
        OutputStream fileOut = new BufferedOutputStream(new FileOutputStream(file));
        
        // Set some FOP settings
        FOUserAgent userAgent = getFopFactory().newFOUserAgent();
        userAgent.setProducer("Apache FOP");
        userAgent.setCreator("API");
        // This is how I set DPI
        userAgent.setTargetResolution(dpi);

        Fop fop = getFopFactory().newFop(MimeConstants.MIME_PNG, userAgent, fileOut);
        TransformerFactory factory = TransformerFactory.newInstance();
        Transformer transformer = factory.newTransformer(xslString);
        
        Result result = new SAXResult(fop.getDefaultHandler());
        transformer.transform(xmlString, result);
        return fileOut;
    }

private FopFactory getFopFactory() {
    if (fopFactory == null) {
        try {
            fopFactory = FopFactory.newInstance(new File("resources/fop_config.xml").toURI());
        } catch (Exception ex) {
            throw ex;
        }
    }
    return factory;
}

谢谢你的帮助！

标签： javaapache-fopdpi