工作中遇到模板中的html，需要转化成pdf作为附件上传到系统

于是经过研究分析，得出用freemarker和itextpdf结合

maven需要导入包：

		<dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-freemarker</artifactId></dependency><dependency><groupId>com.itextpdf</groupId><artifactId>itextpdf</artifactId><version>${itextpdf.version}</version></dependency><dependency><groupId>com.itextpdf.tool</groupId><artifactId>xmlworker</artifactId><version>5.5.8</version></dependency><dependency><groupId>com.itextpdf</groupId><artifactId>itext-asian</artifactId><version>5.2.0</version></dependency>

新建FreemarkerUtils工具类

package com.example.common.util;import cn.hutool.core.util.StrUtil;
import com.itextpdf.text.*;
import com.itextpdf.text.pdf.BaseFont;
import com.itextpdf.text.pdf.PdfWriter;
import com.itextpdf.tool.xml.XMLWorkerFontProvider;
import freemarker.core.HTMLOutputFormat;
import freemarker.template.Configuration;
import freemarker.template.Template;
import lombok.extern.slf4j.Slf4j;
import org.springframework.stereotype.Component;
import org.springframework.ui.freemarker.FreeMarkerTemplateUtils;
import javax.annotation.Resource;
import java.io.*;
import java.nio.charset.Charset;
import java.nio.charset.StandardCharsets;
import java.nio.file.Files;
import java.nio.file.Paths;
import java.util.Map;import com.itextpdf.tool.xml.XMLWorkerHelper;@Component
@Slf4j
public class FreemarkerUtils {@Resourceprivate Configuration stringConfiguration;private static final String FONT = "fonts/simhei.ttf";/*** 根据模板构建* @param content 模板内容* @param dataModel 模板数据**/public String buildByTemplate(String content, Map<String,Object> dataModel){return buildByTemplate(content, dataModel, StrUtil.EMPTY);}/*** 根据模板替换变量，得到变量替换后的内容* @param content 模板内容* @param dataModel 模板数据* @param defaultString 构建失败返回的默认值**/public String buildByTemplate(String content, Map<String,Object> dataModel,String defaultString) {try {
//            stringConfiguration.setOutputFormat(HTMLOutputFormat.INSTANCE);return FreeMarkerTemplateUtils.processTemplateIntoString(new Template("", content,   stringConfiguration),dataModel);}catch (Exception e){log.warn("解析模板失败", e);}return defaultString;}public void htmlToPdf(String content) {// 创建一个Document对象Document document = new Document();try {// 创建一个PdfWriter实例来写PDF文件PdfWriter writer = PdfWriter.getInstance(document, Files.newOutputStream(Paths.get("E:\\张三测试.pdf")));// 打开文档document.open();InputStream inputStream = new ByteArrayInputStream(content.getBytes(StandardCharsets.UTF_8));FontProviderUtil fontProviderUtil = new FontProviderUtil();// 读取HTML文件并将其转换为PDFXMLWorkerHelper.getInstance().parseXHtml(writer, document,inputStream, null, StandardCharsets.UTF_8, fontProviderUtil);// 关闭文档document.close();} catch (DocumentException | IOException e) {e.printStackTrace();}}}

 解决中文乱码和生成的pdf中文不显示问题

package com.example.common.util;import com.itextpdf.text.BaseColor;
import com.itextpdf.text.Font;
import com.itextpdf.text.pdf.BaseFont;
import com.itextpdf.tool.xml.XMLWorkerFontProvider;
import lombok.extern.slf4j.Slf4j;/*** 字体*/
@Slf4j
public class FontProviderUtil extends XMLWorkerFontProvider {/*** 黑体 常规**/public static final String SIMHEI_TTF = "fonts/simhei.ttf";/*** 解决乱码和中文在pdf不显示问题* @param fontname    the name of the font* @param encoding    the encoding of the font* @param embedded    true if the font is to be embedded in the PDF* @param size	    the size of this font* @param style	    the style of this font* @param color	    the <CODE>BaseColor</CODE> of this font.* @param cached 		true if the font comes from the cache or is added to* 				the cache if new, false if the font is always created new* @return*/@Overridepublic Font getFont(String fontname, String encoding, boolean embedded, float size, int style, BaseColor color, boolean cached) {BaseFont bf = null;try {bf = BaseFont.createFont(SIMHEI_TTF, BaseFont.IDENTITY_H, BaseFont.NOT_EMBEDDED);} catch (Exception e) {log.info(e.getMessage());e.printStackTrace();}Font font = new Font(bf, size, style, color);font.setColor(color);return font;}}

在业务层调用即可

  freemarkerUtils.htmlToPdf(content);