當前位置：首頁 > 前端技术 > HTML >内容正文

HTML

xhtmlrenderer + iText-HTML转PDF

發布時間：2024/7/23 HTML 35 豆豆

生活随笔收集整理的這篇文章主要介紹了 xhtmlrenderer + iText-HTML转PDF 小編覺得挺不錯的,現在分享給大家,幫大家做個參考.

來源：xhtmlrenderer + iText-HTML轉PDF_hunan961的博客-CSDN博客_xhtmlrenderer

xhtmlrendere+itext2.0.8 將html轉成pdf，帶樣式、圖片(也支持二維碼、條形碼)等

主要步驟

生成html（css樣式直接放在style中）

html轉換pdf方法

數據返回給前端

詳細過程

html模板：

private static final String DEFAULT_HTML = "<!DOCTYPE html PUBLIC \"-//W3C//DTD XHTML 1.0 Transitional//EN\" \"http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd\">\n" +"<html xmlns=\"http://www.w3.org/1999/xhtml\">\n" +"<head>\n" +"<meta charset=\"utf-8\" />\n" +"<style> \n" +" body{ padding:0; margin:0; font-family:Microsoft YaHei; @page {size:20mm, 35mm;}} \n" +"</style>\n" +"</head>\n" +"<body>\n" +" ${CONTENT}\n" +"</body>\n" +"</html>";

實際內容替換DEFAULT_HTML中的${CONTENT}

2.html轉pdf

方法代碼：?

public static void htmlToPdf2(String html, ByteArrayOutputStream os) throws IOException {try {ITextRenderer renderer = new ITextRenderer();renderer.setDocumentFromString(html);ITextFontResolver fontResolver = renderer.getFontResolver();// 獲取字體文件路徑fontResolver.addFont(getFontPath2(), BaseFont.IDENTITY_H, BaseFont.NOT_EMBEDDED);renderer.getSharedContext().setReplacedElementFactory(new ImgReplacedElementFactory());renderer.layout();renderer.createPDF(os);os.flush();} catch (Exception e) {logger.error("Html:" + html);logger.error("Html To Pdf Failed", e);// throw new CommonException("Html To Pdf Failed:" + e.getMessage());} finally {if (os != null) {os.close();}}}// 字體路徑 private static String getFontPath2() {return HrptConstants.FONT_PATH + File.separator + HrptConstants.TTF_NAME_2;} /*** <p>* 圖片處理優化-支持html中img標簽的src為url或者base64* </p>*/public class ImgReplacedElementFactory implements ReplacedElementFactory {private final static String IMG_ELEMENT_NAME = "img";private final static String SRC_ATTR_NAME = "src";private final static String URL_PREFIX_NAME = "data:image";private final static String URL_BASE64 = "base64,";private final static Logger LOGGER = LoggerFactory.getLogger(ImgReplacedElementFactory.class);@Overridepublic ReplacedElement createReplacedElement(LayoutContext c, BlockBox box, UserAgentCallback uac, int cssWidth, int cssHeight) {Element e = box.getElement();if (e == null) {return null;}String nodeName = e.getNodeName();// 找到img標簽if (nodeName.equals(IMG_ELEMENT_NAME)) {String url = e.getAttribute(SRC_ATTR_NAME);FSImage fsImage;try {InputStream imageStream = this.getImageStream(url, BaseConstants.Digital.ZERO);byte[] bytes = IOUtils.toByteArray(imageStream);// 生成itext圖像fsImage = new ITextFSImage(Image.getInstance(bytes));} catch (Exception e1) {fsImage = null;}if (fsImage != null) {// 對圖像進行縮放if (cssWidth != -1 || cssHeight != -1) {fsImage.scale(cssWidth, cssHeight);}return new ITextImageElement(fsImage);}}return null;}@Overridepublic void reset() {}@Overridepublic void remove(Element e) {}@Overridepublic void setFormSubmissionListener(FormSubmissionListener listener) {}/*** 重復獲取網絡圖片3次，若三次失敗則不再獲取* @param url* @param tryCount* @return*/private InputStream getImageStream(String url, int tryCount) {if (tryCount > BaseConstants.Digital.TWO) {return null;}if (URL_PREFIX_NAME.equals(url.substring(0, 10))) {byte[] bytes = Base64.decode(url.substring(url.indexOf(URL_BASE64) + 7));//轉化為輸入流return new ByteArrayInputStream(bytes);}try {HttpURLConnection connection = (HttpURLConnection) new URL(url).openConnection();connection.setReadTimeout(5000);connection.setConnectTimeout(5000);connection.setRequestMethod("GET");if (connection.getResponseCode() == HttpURLConnection.HTTP_OK) {InputStream inputStream = connection.getInputStream();return inputStream;} else {tryCount += 1;LOGGER.info("connectionError : {} , msg : {}", connection.getResponseCode(), connection.getResponseMessage());return getImageStream(url, tryCount);}} catch (IOException e) {LOGGER.error("connectionIOException : {} , trace : {}", e.getMessage(), e.getStackTrace());}return null;}}

3.最后通過response導出pdf給前端

最后，對于在開發過程中碰到的問題，做下記錄和總結。

字體問題，漢字不顯示
html模板body里面font-family屬性不要落了

字體路徑要找的到你的字體文件?

font-family屬性中的字體要和應用的字體文件字體相對應，舉例：font-family中設置的是Microsoft YaHei字體，那么添加的字體文件就一定要是微軟雅黑的(圖中的msyh.ttc就是微軟雅黑的字體文件)

字體下載：常用的字體在windows的自帶font文件夾下基本上都有，實在沒有就去網上自己找吧?

html中的img圖片標簽后綴問題

xhtmlrenderer會對html轉成xml，所以對于html格式要求嚴格，現在前端生成的html中img標簽往往都是不帶后綴的，所以在接口調用時會報錯，小問題，把html中的img加上后綴就好

// templateContent -- html內容Document doc = Jsoup.parse(templateContent);// img標簽后綴處理Elements img = doc.getElementsByTag("img");if (!img.isEmpty()) {for (Element element:img) {if (!element.toString().contains("/>") && !element.toString().contains("</img>")) {templateContent = templateContent.replace(element.toString(),element.toString() + "</img>");}}}

接口報錯，html轉pdf報錯。
Html To Pdf Failed:Cant load the XML resource (using TRaX transformer). org.w 3c.dom.DOMException: NOT_FOUND_ERR: An attempt is made to reference a node in a context where it does n ot exist.

?這個問題蠻困擾的，html明明沒有問題，然后一步一步debug發現，是因為html中有些標簽中加了id屬性導致的，根據源碼看到的是，id轉xml默認給的namespace都是空字符串而導致，查看http://www.w3.org/1999/xhtml也沒看到說div標簽和img標簽支持id屬性，最后做了html字符串處理，把id替換成了title

// id處理，Element對象不支持id屬性templateContent = templateContent.replaceAll("id=","title=");

img圖片src為base64 code出現的一點問題

這里的業務場景是HTML中會有二維碼或者條形碼，用的都是img標簽，后端會使用實際數據（這里是資產的編碼）的二進制內容轉成base64編碼然后放入src中
替換，主要注意要加前綴URL_PREFIX_NAME ：

private final static String ID_BAR = "stylesBarCode";private final static String ID_QR = "stylesQrCode";private final static String SRC_ATTR_NAME = "src";private final static String URL_PREFIX_NAME = "data:image/png;base64,";private final static String CHARACTER_ENCODING = "utf-8";// img的src處理Element barElement = doc.getElementById(ID_BAR);Element qrElement = doc.getElementById(ID_QR);Base64.Encoder encoder = Base64.getEncoder();if (barElement != null) {byte[] bytes = CodeUtils.generateBarCode(assetVO.getAspAssetNum(), 60, 5, CHARACTER_ENCODING, "code39");templateContent = templateContent.replace(barElement.attr(SRC_ATTR_NAME), URL_PREFIX_NAME + encoder.encodeToString(bytes));}if (qrElement != null) {byte[] bytes = CodeUtils.generateQrCode(assetVO.getAspAssetNum(), 20, 20, CHARACTER_ENCODING);templateContent = templateContent.replace(qrElement.attr(SRC_ATTR_NAME), URL_PREFIX_NAME + encoder.encodeToString(bytes));}

工具方法，生成二維碼，生成條形碼（用的zxing）：

/*** 生成二維碼** @param text 內容* @param width 寬* @param height 高* @param characterEncoding 字符編碼* @return 二進制內容*/public static byte[] generateQrCode(String text, int width, int height, String characterEncoding) {QRCodeWriter writer = new QRCodeWriter();HashMap<EncodeHintType, Object> config = new HashMap<>(BaseConstants.Digital.SIXTEEN);config.put(EncodeHintType.CHARACTER_SET, characterEncoding);try (ByteArrayOutputStream stream = new ByteArrayOutputStream()) {BitMatrix bar = writer.encode(text, BarcodeFormat.QR_CODE, width, height, config);MatrixToImageWriter.writeToStream(bar, HrptConstants.ImageType.PNG, stream);return stream.toByteArray();} catch (Exception e) {throw new CommonException(HrptMessageConstants.ERROR_GENERATE_QRCODE);}}/*** 生成條形碼** @param text 內容* @param width 寬* @param height 高* @param characterEncoding 字符編碼* @param barCodeType 條形碼類型* @return 二進制內容*/public static byte[] generateBarCode(String text, int width, int height, String characterEncoding, String barCodeType) {BarCodeType codeType = BarCodeType.valueOf2(barCodeType);switch (codeType) {case CODE_39:return generateBarCode39(text, width, height, characterEncoding);case CODE_93:return generateBarCode93(text, width, height, characterEncoding);case CODE_128:return generateBarCode128(text, width, height, characterEncoding);default:throw new CommonException(HrptMessageConstants.UNSUPPORTED_CODE_TYPE);}}/*** 生成Code39條形碼** @param text 內容* @param width 寬* @param height 高* @param characterEncoding 字符編碼* @return 二進制內容*/public static byte[] generateBarCode39(String text, int width, int height, String characterEncoding) {Code39Writer writer = new Code39Writer();HashMap<EncodeHintType, Object> config = new HashMap<>(BaseConstants.Digital.SIXTEEN);config.put(EncodeHintType.CHARACTER_SET, characterEncoding);try (ByteArrayOutputStream stream = new ByteArrayOutputStream()) {BitMatrix bar = writer.encode(text, BarcodeFormat.CODE_39, width, height, config);MatrixToImageWriter.writeToStream(bar, HrptConstants.ImageType.PNG, stream);return stream.toByteArray();} catch (Exception e) {throw new CommonException(HrptMessageConstants.ERROR_GENERATE_BARCODE);}}/*** 生成Code93條形碼** @param text 內容* @param width 寬* @param height 高* @param characterEncoding 字符編碼* @return 二進制內容*/public static byte[] generateBarCode93(String text, int width, int height, String characterEncoding) {Code93Writer writer = new Code93Writer();HashMap<EncodeHintType, Object> config = new HashMap<>(BaseConstants.Digital.SIXTEEN);config.put(EncodeHintType.CHARACTER_SET, characterEncoding);try (ByteArrayOutputStream stream = new ByteArrayOutputStream()) {BitMatrix bar = writer.encode(text, BarcodeFormat.CODE_93, width, height, config);MatrixToImageWriter.writeToStream(bar, HrptConstants.ImageType.PNG, stream);return stream.toByteArray();} catch (Exception e) {throw new CommonException(HrptMessageConstants.ERROR_GENERATE_BARCODE);}}/*** 生成Code128條形碼** @param text 內容* @param width 寬* @param height 高* @param characterEncoding 字符編碼* @return 二進制內容*/public static byte[] generateBarCode128(String text, int width, int height, String characterEncoding) {Code128Writer writer = new Code128Writer();HashMap<EncodeHintType, Object> config = new HashMap<>(BaseConstants.Digital.SIXTEEN);config.put(EncodeHintType.CHARACTER_SET, characterEncoding);try (ByteArrayOutputStream stream = new ByteArrayOutputStream()) {BitMatrix bar = writer.encode(text, BarcodeFormat.CODE_128, width, height, config);MatrixToImageWriter.writeToStream(bar, HrptConstants.ImageType.PNG, stream);return stream.toByteArray();} catch (Exception e) {throw new CommonException(HrptMessageConstants.ERROR_GENERATE_BARCODE);}}

ImgReplacedElementFactory類中的getImageStream方法（代碼上文貼過了）

如果是base64地址的就不用http請求了，直接轉二進制再轉InputStream，需要注意的是Base64的import不要用錯了，否則圖片解析不出

import com.lowagie.text.pdf.codec.Base64;

總結

以上是生活随笔為你收集整理的xhtmlrenderer + iText-HTML转PDF的全部內容，希望文章能夠幫你解決所遇到的問題。

如果覺得生活随笔網站內容還不錯，歡迎將生活随笔推薦給好友。

上一篇： Java加密与解密的艺术~数字证书~模型
下一篇： Java测试驱动开发--总结