SpringBoot项目中基于PDF模板生成插入图片的PDF文档

<!--pdf依赖-->
<dependency>
    <groupId>com.itextpdf</groupId>
    <artifactId>itextpdf</artifactId>
    <version>5.5.13</version>
</dependency>
<dependency>
    <groupId>com.itextpdf.tool</groupId>
    <artifactId>xmlworker</artifactId>
    <version>5.5.13</version>
</dependency>
<!--pdf支持中文-->
<dependency>
    <groupId>com.itextpdf</groupId>
    <artifactId>itext-asian</artifactId>
    <version>5.2.0</version>
</dependency>

package org.dromara.docMake.util;

import cn.hutool.core.bean.BeanUtil;
import cn.hutool.core.util.ObjectUtil;
import cn.hutool.core.util.StrUtil;
import com.itextpdf.text.DocumentException;
import com.itextpdf.text.pdf.AcroFields;
import com.itextpdf.text.pdf.BaseFont;
import com.itextpdf.text.Image;
import com.itextpdf.text.Rectangle;
import com.itextpdf.text.pdf.PdfReader;
import com.itextpdf.text.pdf.PdfStamper;
import io.vertx.core.http.HttpServerRequest;
import io.vertx.core.http.HttpServerResponse;
import jakarta.servlet.ServletOutputStream;
import jakarta.servlet.http.HttpServletRequest;
import jakarta.servlet.http.HttpServletResponse;
import lombok.extern.slf4j.Slf4j;
import org.apache.commons.io.IOUtils;
import org.springframework.core.io.Resource;
import org.springframework.core.io.support.PathMatchingResourcePatternResolver;
import org.springframework.util.ResourceUtils;

import java.io.*;
import java.net.URLEncoder;
import java.util.*;
import java.net.*;

/**
 * @Author: 知识浅谈
 * @Package: org.dromara.docMake.util
 * @Date: 2024-5-10 15:16
 * @Description: pdf生成工具类
 * @Version: 1.0
 */
@Slf4j
public class PdfUtil {
    private static boolean isPrimitiveOrWrapper(Class<?> clazz) {  //检查传入的类是否为基本类型或基本包装类型
        return clazz.isPrimitive() || clazz.getName().startsWith("java.lang");
    }

    //生成pdf
    public static void generatePdf(HttpServletRequest request,
                                   HttpServletResponse response,
                                   String templatePath,//当前为文件名，之后改为文件路径
                                   Map map,
                                   String newFileName) {
        try(OutputStream responseOutputStream = response.getOutputStream(); ByteArrayOutputStream fileOut= new ByteArrayOutputStream()){
            if(!newFileName.endsWith(".pdf")) newFileName=newFileName+".pdf"; //
            //模版在项目中的位置
            Resource resource = new PathMatchingResourcePatternResolver().getResource(ResourceUtils.CLASSPATH_URL_PREFIX + "pdf/" + templatePath);
            PdfReader pdfReader = new PdfReader(resource.getInputStream());
            PdfStamper pdfStamper = new PdfStamper(pdfReader, fileOut);
            BaseFont font = BaseFont.createFont(BaseFont.HELVETICA_BOLD, BaseFont.WINANSI, BaseFont.EMBEDDED);
            ArrayList<BaseFont> fontList = new ArrayList<>();
            fontList.add(font);

            //取出报表模版中的所有字段
            AcroFields fields = pdfStamper.getAcroFields();
            fields.setSubstitutionFonts(fontList);
            //根据占位符，填充图片
            if(map.containsKey("头像")){   //假设要替换的占位符是头像这个占位符的位置
          	  	PdfUtil.fillPic(fields,pdfStamper,(String)map.get("头像")));
          	  	map.remove("头像");
            }

			//根据占位符进行替换，替换对应位置的值
            PdfUtil.fillData(fields,map);


            //必须要调用这个，否则文档不会生成的，如果为false，生成的pdf还能编辑，所以设置为true
            pdfStamper.setFormFlattening(true);
            pdfStamper.close();
            writeFile(request,response,fileOut,newFileName);
        }catch (Exception e){
            e.printStackTrace();
        }
    }

    /**
     * 填充数据
     */
    private static void fillData(AcroFields fields,Map<String,String> data) throws IOException, DocumentException {
        Map<String, AcroFields.Item> formFields = fields.getFields();
        String v;
        for (String k : data.keySet()) {
            if(formFields.containsKey(k)){
                v = data.get(k);
                fields.setField(k,v);
            }
        }
    }
    /**
     * 填充图像
     */
    private static void fillPic(AcroFields fields,PdfStamper pdfStamper,String headUrl) throws Exception{
        //获取头像占位符中要替换的图片位置
        AcroFields.FieldPosition headPosition = fields.getFieldPosition("头像").get(0);
        Rectangle position = headPosition.position;
        URL url = new URL(headUrl);
    	Image image = Image.getInstance(url);
    	//根据位置调整图片大小
    	image.scaleToFit(position.getWidth(),position.getHeight());
    	//设置图片位置
        image.setAbsolutePosition(position.getLeft(),position.getBottom());
        PdfContentByte content = pdfStamper.getOverContent(headPosition.page);
        content.addImage(image); //添加图片
    }
    private static void writeFile(HttpServletRequest request,
                                  HttpServletResponse response,
                                  ByteArrayOutputStream fileOut,
                                  String newFileName) throws IOException{

        response.setCharacterEncoding(request.getCharacterEncoding());
        response.setContentType("application/pdf");
        try{
            //这里主要防止下载的pdf文件名乱码
            response.setHeader("Content-Disposition","attachment; filename="+ URLEncoder.encode(newFileName,"UTF-8"));
            fileOut.writeTo(response.getOutputStream());
            response.flushBuffer();
        }catch (Exception e){
            log.error("pdf生成异常");
            throw new RuntimeException("pdf生成异常");
        }
    }

}

@GetMapping("/pdfTest")
public void test(HttpServletRequest request, HttpServletResponse response) {
    Map<String,String> map = new HashMap<>();
    map.put("测试","要替换的内容");
    map.put("头像","https://i-blog.csdnimg.cn/blog_migrate/2d9a150283cb6c437a5af251e0226136.png");
    PdfUtil.generatePdf(request,response,"test.pdf",a,"测试");
}