更新时间:2021-11-08 10:01:56
您需要实现自定义图像标记处理器来处理嵌入在html中的图像:
You need to implement a custom image tag processor to process the images embedded inside your html:
package com.example.itext.processor;
import java.util.ArrayList;
import java.util.List;
import java.util.Map;
import com.itextpdf.text.Chunk;
import com.itextpdf.text.Element;
import com.itextpdf.text.Image;
import com.itextpdf.text.log.Level;
import com.itextpdf.text.log.Logger;
import com.itextpdf.text.log.LoggerFactory;
import com.itextpdf.text.pdf.codec.Base64;
import com.itextpdf.tool.xml.NoCustomContextException;
import com.itextpdf.tool.xml.Tag;
import com.itextpdf.tool.xml.WorkerContext;
import com.itextpdf.tool.xml.exceptions.LocaleMessages;
import com.itextpdf.tool.xml.exceptions.RuntimeWorkerException;
import com.itextpdf.tool.xml.html.HTML;
import com.itextpdf.tool.xml.pipeline.html.HtmlPipelineContext;
public 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)
*/
@Override
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;
}
}
以下代码段注册自定义图片代码处理器和隐蔽HTML文档到PDF
Following code snippet registers the custom image tag processor and coverts an HTML document to PDF
public static void main(String[] args) {
convertHtmlToPdf();
}
private static void convertHtmlToPdf() {
try {
final OutputStream file = new FileOutputStream(new File("C:\\Test.pdf"));
final Document document = new Document();
final PdfWriter writer = PdfWriter.getInstance(document, file);
document.open();
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 StyleAttrCs-s-resolver cssResolver = new StyleAttrCs-s-resolver(cssFiles);
final HtmlPipelineContext hpc = new HtmlPipelineContext(new CssAppliersImpl(new XMLWorkerFontProvider()));
hpc.setAcceptUnknown(true).autoBookmark(true).setTagFactory(tagProcessorFactory);
final HtmlPipeline htmlPipeline = new HtmlPipeline(hpc, new PdfWriterPipeline(document, writer));
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 FileInputStream("C:\\test.html");
xmlParser.parse(is, charset);
is.close();
document.close();
file.close();
} catch (Exception e) {
e.printStackTrace();
// TODO
}
}