动态jsp页面转PDF输出到页面的实现方法

String html = ServletUtils.forward(request,response,"/WEB-INF/jsp/depot/print/jhd.jsp"); //转发请求到jsp，返回解析之后的内容而不是输出到浏览器//System.out.println(html);byte[] pdf = PDFUtils.html2pdf(html);response.setContentType("application/pdf");response.setHeader("Content-Length",String.valueOf(pdf.length));response.setHeader("Connection","keep-alive");response.setHeader("Accept-Ranges","none");response.setHeader("X-Frame-Options","DENY");OutputStream out = response.getOutputStream();out.write(pdf);out.flush();public class ServletUtils {/*** 此forward方法执行完毕之后不会输出内容到浏览器，而是把输出到字节流，最后以字符串的形式返回* @param request* @param response* @param src* @return*/public static String forward(HttpServletRequest request, HttpServletResponse response, String src) {try{/* ↓↓↓↓↓重新构造response，修改response中的输出流对象，使其输出到字节数组↓↓↓↓↓ */final ByteArrayOutputStream byteArrayOutputStream = new ByteArrayOutputStream();final ServletOutputStream servletOuputStream = new ServletOutputStream() {@Overridepublic void write(int b) throws IOException {byteArrayOutputStream.write(b);}@Overridepublic boolean isReady() {return false;}@Overridepublic void setWriteListener(WriteListener writeListener) {}};final PrintWriter printWriter = new PrintWriter(new OutputStreamWriter(byteArrayOutputStream, "UTF-8"));response = new HttpServletResponseWrapper(response) {public ServletOutputStream getOutputStream() {return servletOuputStream;}public PrintWriter getWriter() {return printWriter;}};/* ↑↑↑↑↑↑重新构造response，修改response中的输出流对象，使其输出到字节数组↑↑↑↑↑↑ *///执行forward操作request.getRequestDispatcher(src).forward(request,response);//把字节流中的内容太转为字符串return new String(byteArrayOutputStream.toByteArray(),"utf-8");}catch (Exception e){throw new RuntimeException(e);}}}import com.itextpdf.text.*;import com.itextpdf.text.pdf.PdfWriter;import com.itextpdf.tool.xml.Pipeline;import com.itextpdf.tool.xml.XMLWorker;import com.itextpdf.tool.xml.XMLWorkerFontProvider;import com.itextpdf.tool.xml.XMLWorkerHelper;import com.itextpdf.tool.xml.exceptions.CssResolverException;import com.itextpdf.tool.xml.html.CssAppliers;import com.itextpdf.tool.xml.html.CssAppliersImpl;import com.itextpdf.tool.xml.html.Tags;import com.itextpdf.tool.xml.parser.XMLParser;import com.itextpdf.tool.xml.pipeline.css.CSSResolver;import com.itextpdf.tool.xml.pipeline.css.CssResolverPipeline;import com.itextpdf.tool.xml.pipeline.end.PdfWriterPipeline;import com.itextpdf.tool.xml.pipeline.html.HtmlPipeline;import com.itextpdf.tool.xml.pipeline.html.HtmlPipelineContext;import java.io.*;/*** pdf工具类*/public class PDFUtils {/*** 把html转换成pdf，以字节数组的形式返回pdf文件* @param html* @return pdf字节数组* @throws IOException* @throws DocumentException* @throws CssResolverException*/public static byte[] html2pdf(String html) throws IOException, DocumentException,CssResolverException {Document document = new Document(PageSize.A4);ByteArrayOutputStream os = new ByteArrayOutputStream();PdfWriter writer = PdfWriter.getInstance(document,os);document.open();XMLWorkerFontProvider fontProvider = new XMLWorkerFontProvider(){@Overridepublic Font getFont(String fontname, String encoding, float size, int style) {return super.getFont(fontname == null ? "宋体" : fontname, encoding, size, style);}};fontProvider.addFontSubstitute("lowagie", "garamond");fontProvider.setUseUnicode(true);//使用我们的字体提供器，并将其设置为unicode字体样式CssAppliers cssAppliers = new CssAppliersImpl(fontProvider);HtmlPipelineContext htmlContext = new HtmlPipelineContext(cssAppliers);htmlContext.setTagFactory(Tags.getHtmlTagProcessorFactory());CSSResolver cssResolver = XMLWorkerHelper.getInstance().getDefaultCssResolver(true);Pipeline<?> pipeline = new CssResolverPipeline(cssResolver,new HtmlPipeline(htmlContext, new PdfWriterPipeline(document,writer)));XMLWorker worker = new XMLWorker(pipeline, true);XMLParser p = new XMLParser(worker);p.parse(new InputStreamReader(new ByteArrayInputStream(html.getBytes("gbk"))));document.close();return os.toByteArray();}}