使用freemarker和itextpdf结合，将html转化为pdf

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：

		
			org.springframework.boot
			spring-boot-starter-freemarker
		
		
			com.itextpdf
			itextpdf
			${itextpdf.version}
		
		
			com.itextpdf.tool
			xmlworker
			5.5.8
		
		
			com.itextpdf
			itext-asian
			5.2.0
		

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 {
    @Resource
    private 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 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 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PDF
            XMLWorkerHelper.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 BaseColor 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
     */
    @Override
    public 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);