感谢mkl和这个链接https://stackoverflow.com/a/20938015/1729265 我有：

Document document = new Document(PageSize.A4, 72f, 72f, 72f, 72f);
PdfWriter.getInstance(document, resourceImage);
document.open();

for (final PPActityDetail activityDtl : activityList) {
    PdfPCell cell = new PdfPCell();
    cell = new PdfPCell();

    Paragraph p6 = new Paragraph("");

    p6.add(new Chunk("Description:   ", smallBold));

    final TagProcessorFactory tagProcessorFactory = 
    Tags.getHtmlTagProcessorFactory();
    tagProcessorFactory.removeProcessor(HTML.Tag.IMG);
    tagProcessorFactory.addProcessor(new ImageTagProcessor(), HTML.Tag.IMG);

    final CssFilesImpl cssFiles = new CssFilesImpl();
    cssFiles.add(XMLWorkerHelper.getInstance().getDefaultCSS());
    final StyleAttrCSSResolver cssResolver = new StyleAttrCSSResolver(cssFiles);
    final HtmlPipelineContext hpc = new HtmlPipelineContext(new CssAppliersImpl());

    hpc.setAcceptUnknown(true).autoBookmark(true).setTagFactory(tagProcessorFactory);
    final HtmlPipeline htmlPipeline = new HtmlPipeline(hpc, new PdfWriterPipeline(document, pdfWriter));
    final Pipeline<?> pipeline = new CssResolverPipeline(cssResolver, htmlPipeline);
    final XMLWorker worker = new XMLWorker(pipeline, true);
    final Charset charset = Charset.forName("UTF-8");
    final XMLParser xmlParser = new XMLParser(true, worker, charset);
    final InputStream is = new ByteArrayInputStream (ppDescription.getBytes("UTF-8"));
    xmlParser.parse(is, charset);

    cell.addElement(p6);

现在我需要将上面的输出（xmlparser.parse（is，charset））添加到p6中，以便将其包含在表中。我试过：

p6.add(xmlParser.parse(is, charset));

但是，这给了我一个错误信息：

The method add(Element) in the type Paragraph is not applicable for the arguments (void)

这是修改后的类：

class ImageTagProcessor extends com.itextpdf.tool.xml.html.Image {

    private final Logger logger = LoggerFactory.getLogger(getClass());

    /*
     * (non-Javadoc)
     * 
     * @see com.itextpdf.tool.xml.TagProcessor#endElement(com.itextpdf.tool.xml.Tag, java.util.List, com.itextpdf.text.Document)
     */
    public List<Element> end(final WorkerContext ctx, final Tag tag, final List<Element> currentContent) {
        final Map<String, String> attributes = tag.getAttributes();
        String src = attributes.get(HTML.Attribute.SRC);
        List<Element> elements = new ArrayList<Element>(1);
        if (null != src && src.length() > 0) {
            Image img = null;
            if (src.startsWith("data:image/")) {
                final String base64Data = src.substring(src.indexOf(",") + 1);
                try {
                    img = Image.getInstance(Base64.decode(base64Data));
                } catch (Exception e) {
                    if (logger.isLogging(Level.ERROR)) {
                        logger.error(String.format(LocaleMessages.getInstance().getMessage(LocaleMessages.HTML_IMG_RETRIEVE_FAIL), src), e);
                    }
                }
                if (img != null) {
                    try {
                        final HtmlPipelineContext htmlPipelineContext = getHtmlPipelineContext(ctx);
                        elements.add(getCssAppliers().apply(new Chunk((com.itextpdf.text.Image) getCssAppliers().apply(img, tag, htmlPipelineContext), 0, 0, true), tag,
                            htmlPipelineContext));
                    } catch (NoCustomContextException e) {
                        throw new RuntimeWorkerException(e);
                    }
                }
            }

            if (img == null) {
                elements = super.end(ctx, tag, currentContent);
            }
        }
        return elements;
    }
}