HTML转PDF字体的坑，搞了半天

itext提供可HTML转PDF的工具包，但是在中文字体时也许会遇到意想不到的问题。特别宋体对应的粗体。

0x01：引入itext包

com.itextpdf itext7-core 7.1.11 pom com.itextpdf html2pdf 2.0.2

0x02：要转换的HTML文件

iText

0x03：编写代码

import java.io.IOException; import com.itextpdf.io.font.FontConstants; import com.itextpdf.kernel.events.Event; import com.itextpdf.kernel.events.IEventHandler; import com.itextpdf.kernel.events.PdfDocumentEvent; import com.itextpdf.kernel.font.PdfFontFactory; import com.itextpdf.kernel.geom.Rectangle; import com.itextpdf.kernel.pdf.canvas.PdfCanvas; import com.itextpdf.layout.Document; public class TextFooterEventHandler implements IEventHandler { private Document doc; private int page; public TextFooterEventHandler(Document doc) { this.doc = doc; } public void handleEvent(Event event) { PdfDocumentEvent docEvent = (PdfDocumentEvent) event; PdfCanvas canvas = new PdfCanvas(docEvent.getPage()); Rectangle pageSize = docEvent.getPage().getPageSize(); page++; canvas.beginText(); try { canvas.setFontAndSize(PdfFontFactory.createFont(FontConstants.HELVETICA_OBLIQUE), 15); } catch (IOException e) { e.printStackTrace(); } canvas.moveText((pageSize.getRight() - doc.getRightMargin() + (pageSize.getLeft() + doc.getLeftMargin())) / 2, pageSize.getBottom() + doc.getBottomMargin()) .showText("" + page).endText().release(); } }

• itext默认字体

public static void defaultFont() throws Exception{ try { String pdfPath = "C:\Users\2230\Desktop\a\defaultFont.pdf"; PdfWriter pdfWriter = new PdfWriter(new File(pdfPath)); PdfDocument pdfDocument = new PdfDocument(pdfWriter) ; Document doc = new Document(pdfDocument); pdfDocument.setDefaultPageSize(PageSize.A4); pdfDocument.addEventHandler(PdfDocumentEvent.END_PAGE, new TextFooterEventHandler(doc)); ConverterProperties pro = new ConverterProperties(); FontProvider fontProvider = new DefaultFontProvider(); fontProvider.addSystemFonts(); pro.setFontProvider(fontProvider); HtmlConverter.convertToPdf(new FileInputStream("C:\Users\2230\Desktop\a\d.html"), pdfDocument, pro); } catch (Exception e) { e.printStackTrace(); } }

默认转换结果

• 加载宋体

这里只加载了宋体，没有加载宋粗体

public static void songTiDefaultFont() throws Exception{ try{ String pdfPath = "C:\Users\2230\Desktop\a\songTiDefaultFont.pdf"; PdfWriter pdfWriter = new PdfWriter(new File(pdfPath)); PdfDocument pdfDocument = new PdfDocument(pdfWriter) ; Document doc = new Document(pdfDocument); pdfDocument.setDefaultPageSize(PageSize.A4); pdfDocument.addEventHandler(PdfDocumentEvent.END_PAGE, new TextFooterEventHandler(doc)); ConverterProperties pro = new ConverterProperties(); FontProvider fontProvider = new DefaultFontProvider(); //宋体 FontProgram fontProgram1 = FontProgramFactory.createFont("C:\Users\2230\Desktop\a\simsun.ttc,1"); fontProvider.addFont(fontProgram1); pro.setFontProvider(fontProvider); HtmlConverter.convertToPdf(new FileInputStream("C:\Users\2230\Desktop\a\d.html"), pdfDocument, pro); } catch (Exception e) { e.printStackTrace(); } }

发现转换出来的PDF，丢失了字体样式

分析原因发现C:WindowsFonts默认没有宋体粗字体，默认只有宋体常规

网上下载宋体粗字体宋体-粗体.ttf，下载的都是ttf格式；代码加载宋体粗字体

public static void songTiDefaultFont() throws Exception{ try{ String pdfPath = "C:\Users\2230\Desktop\a\songTiDefaultFont.pdf"; PdfWriter pdfWriter = new PdfWriter(new File(pdfPath)); PdfDocument pdfDocument = new PdfDocument(pdfWriter) ; Document doc = new Document(pdfDocument); pdfDocument.setDefaultPageSize(PageSize.A4); pdfDocument.addEventHandler(PdfDocumentEvent.END_PAGE, new TextFooterEventHandler(doc)); ConverterProperties pro = new ConverterProperties(); FontProvider fontProvider = new DefaultFontProvider(); //宋体 FontProgram fontProgram1 = FontProgramFactory.createFont("C:\Users\2230\Desktop\a\simsun.ttc,1"); fontProvider.addFont(fontProgram1); //宋体粗体 FontProgram fontProgram2 = FontProgramFactory.createFont("C:\Users\2230\Desktop\a\宋体-粗体.ttf"); fontProvider.addFont(fontProgram2); pro.setFontProvider(fontProvider); HtmlConverter.convertToPdf(new FileInputStream("C:\Users\2230\Desktop\a\d.html"), pdfDocument, pro); } catch (Exception e) { e.printStackTrace(); } }

多加了如下代码：

执行直接报错，字体无法加载

• 把ttf转换成otf格式字体

在线转换工具：https://www.fontke.com/tool/convfont

public static void songConvertTiFont() throws Exception{ try{ String pdfPath = "C:\Users\2230\Desktop\a\songTiFont.pdf"; PdfWriter pdfWriter = new PdfWriter(new File(pdfPath)); PdfDocument pdfDocument = new PdfDocument(pdfWriter) ; Document doc = new Document(pdfDocument); pdfDocument.setDefaultPageSize(PageSize.A4); pdfDocument.addEventHandler(PdfDocumentEvent.END_PAGE, new TextFooterEventHandler(doc)); ConverterProperties pro = new ConverterProperties(); FontProvider fontProvider = new DefaultFontProvider(); fontProvider.addSystemFonts(); //宋体 FontProgram fontProgram1 = FontProgramFactory.createFont("C:\Users\2230\Desktop\a\simsun.ttc,0"); fontProvider.addFont(fontProgram1); //宋体粗体 FontProgram fontProgram2 = FontProgramFactory.createFont("C:\Users\2230\Desktop\a\宋体-粗体.otf"); fontProvider.addFont(fontProgram2); pro.setFontProvider(fontProvider); HtmlConverter.convertToPdf(new FileInputStream("C:\Users\2230\Desktop\a\d.html"), pdfDocument, pro); } catch (Exception e) { e.printStackTrace(); } }

转换结果