private static void renderPDF(String html, OutputStream outputStream) throws Exception {
        try {
            PdfRendererBuilder builder = new PdfRendererBuilder();
            addFont(builder, "D:\\font\\");
            builder.useUnicodeBidiSplitter(new ICUBidiSplitter.ICUBidiSplitterFactory());
            builder.useUnicodeBidiReorderer(new ICUBidiReorderer());
            builder.defaultTextDirection(TextDirection.LTR);
            builder.useSVGDrawer(new BatikSVGDrawer());
            builder.useObjectDrawerFactory(buildObjectDrawerFactory());
　　　　　　　//这一段可以忽略、正则处理内容（没有优化）
            String h = html.replaceAll("<!--[\\w\\W\r\\n]*?-->", "").replaceAll("(?i)<img+([^>]*?[\\s\"])[(.*?)>]", "<img$1/>").replaceAll("&nbsp;", " ").replaceAll("(ng-bind=\"|ng-class=\"|ng-src=http://www.mamicode.com/"|ng-style=\")(.*?)\"", "");
            builder.withHtmlContent(h, TestcaseRunner.class.getResource("/testcases/").toString());
            builder.toStream(outputStream);
            builder.run();
        } finally {
            outputStream.close();
        }
    }

    /**
     * 添加字体库
     * @param builder
     * @param dir
     */
    private static void addFont(PdfRendererBuilder builder, String dir) {
        File f = new File(dir);
        if (f.isDirectory()) {
            File[] files = f.listFiles(new FilenameFilter() {
                public boolean accept(File dir, String name) {
                    String lower = name.toLowerCase();
//                    lower.endsWith(".otf") ||  对otf库的字体支持有问题，暂时屏蔽
                    return lower.endsWith(".ttf") || lower.endsWith(".ttc");
                }
            });
            for (File subFile:files) {
                String fontFamily = subFile.getName().substring(0, subFile.getName().lastIndexOf("."));
                builder.useFont(subFile, fontFamily);
            }
        }
    }

for (File subFile:files) {
                String fontFamily = subFile.getName().substring(0, subFile.getName().lastIndexOf("."));
　　　　　　　　　 //核心代码
                //自定义规则 加粗的库 含有"_"
                // 700 为bold对应的数值、默认为400

                if(fontFamily.indexOf("_") > 0){
                    builder.useFont(subFile, fontFamily.substring(0, fontFamily.indexOf("_")), 700, FontStyle.NORMAL, true);
                }else{
                    builder.useFont(subFile, fontFamily);
                }
                
            }