SpringBoot+Freemark根据html模板动态导出PDF

1、引入maven

导出pdf的一些必要jar包

		<dependency><groupId>org.projectlombok</groupId><artifactId>lombok</artifactId><optional>true</optional></dependency><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><dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-freemarker</artifactId><version>2.3.6.RELEASE</version></dependency><dependency><groupId>org.freemarker</groupId><artifactId>freemarker</artifactId><version>2.3.28</version></dependency><dependency><groupId>cn.hutool</groupId><artifactId>hutool-all</artifactId><version>5.4.3</version></dependency><dependency><groupId>org.apache.commons</groupId><artifactId>commons-io</artifactId><version>1.3.2</version></dependency>

2、两个工具类

GeneratePDF.java

注意1：工具类中的变量templates 表示在resource建个templates目录， test.html表示生成pdf的模板，water.png表示pdf的水印，这里我没加水印，如果要加水印，只用把下面我注释的三行代码放开就行。
注意2: test.html和water.png都放在templates目录

package cn.yx.zg.utils.pdf;import cn.hutool.core.io.resource.ClassPathResource;
import com.itextpdf.text.*;
import com.itextpdf.text.pdf.PdfContentByte;
import com.itextpdf.text.pdf.PdfGState;
import com.itextpdf.text.pdf.PdfPageEvent;
import com.itextpdf.text.pdf.PdfWriter;
import com.itextpdf.tool.xml.XMLWorkerHelper;import java.io.*;
import java.nio.charset.Charset;public class GeneratePDF {public final static String TEMPLATE_DIRECTORY_INSPECTION = "/templates/";public final static String TEMPLATE_NAME_INSPECTION = "test.html";public final static String TEMPLATE_WATER_INSPECTION = "water.png";/*** HTML 转 PDF** @param content html内容* @param outPath 输出pdf路径* @return 是否创建成功*/public static boolean html2Pdf(String content, String outPath) throws FileNotFoundException {return html2Pdf(content, new FileOutputStream(outPath));}public static boolean html2Pdf(String content, OutputStream out) {try {Document document = new Document(); //创建一个标准的A4纸文档PdfWriter writer = PdfWriter.getInstance(document, out);//书写器与ducument文档关联document.open();//打开文档
//            addWaterMark(writer);writer.setPageEvent(new PdfPageEvent() {@Overridepublic void onOpenDocument(PdfWriter pdfWriter, Document document) {}@Overridepublic void onStartPage(PdfWriter pdfWriter, Document document) {
//                    addWaterMark(pdfWriter);}@Overridepublic void onEndPage(PdfWriter pdfWriter, Document document) {}@Overridepublic void onCloseDocument(PdfWriter pdfWriter, Document document) {}@Overridepublic void onParagraph(PdfWriter pdfWriter, Document document, float v) {}@Overridepublic void onParagraphEnd(PdfWriter pdfWriter, Document document, float v) {}@Overridepublic void onChapter(PdfWriter pdfWriter, Document document, float v, Paragraph paragraph) {}@Overridepublic void onChapterEnd(PdfWriter pdfWriter, Document document, float v) {}@Overridepublic void onSection(PdfWriter pdfWriter, Document document, float v, int i, Paragraph paragraph) {}@Overridepublic void onSectionEnd(PdfWriter pdfWriter, Document document, float v) {}@Overridepublic void onGenericTag(PdfWriter pdfWriter, Document document, Rectangle rectangle, String s) {}});XMLWorkerHelper.getInstance().parseXHtml(writer, document, new ByteArrayInputStream(content.getBytes()), null, Charset.forName("UTF-8"));document.close();//关闭文档} catch (Exception e) {System.out.println("生成模板内容失败" + e.fillInStackTrace());return false;}return true;}/*** HTML 转 PDF** @param content html内容* @return PDF字节数组*/public static byte[] html2Pdf(String content) {ByteArrayOutputStream outputStream = null;try {Document document = new Document();outputStream = new ByteArrayOutputStream();PdfWriter writer = PdfWriter.getInstance(document, outputStream);document.open();XMLWorkerHelper.getInstance().parseXHtml(writer, document, new ByteArrayInputStream(content.getBytes()), null, Charset.forName("UTF-8"));document.close();} catch (Exception e) {System.out.println("------生成pdf失败-------");}return outputStream.toByteArray();}public static void addWaterMark(PdfWriter writer) {Image image = null;try {ClassPathResource resource = new ClassPathResource(TEMPLATE_DIRECTORY_INSPECTION + TEMPLATE_WATER_INSPECTION);image = Image.getInstance(resource.getUrl());// 加入水印PdfContentByte waterMar = writer.getDirectContentUnder();// 开始设置水印waterMar.beginText();// 设置水印透明度PdfGState gs = new PdfGState();// 设置笔触字体不透明度为0.4fgs.setStrokeOpacity(0.2f);gs.setFillOpacity(0.2f);// 设置等比缩放image.scalePercent(25);// 依照比例缩放// image.scaleAbsolute(200,100);//自定义大小image.setRotation(45f);// 设置透明度waterMar.setGState(gs);// 添加水印图片
//                waterMar.addImage(image);image.setAbsolutePosition(110f, 130f);//结束设置waterMar.endText();waterMar.stroke();try {waterMar.addImage(image);} catch (DocumentException e) {e.printStackTrace();} finally {waterMar = null;gs = null;}} catch (BadElementException e) {e.printStackTrace();} catch (IOException e) {e.printStackTrace();}}}

GetHtmlContent.java

package cn.yx.zg.utils.pdf;import freemarker.cache.ClassTemplateLoader;
import freemarker.template.Configuration;
import freemarker.template.Template;import java.io.StringWriter;
import java.io.Writer;
import java.util.Map;public class GetHtmlContent {/*** 获取模板内容** @param templateDirectory 模板文件夹* @param templateName      模板文件名* @param paramMap          模板参数* @return* @throws Exception*/public static String getTemplateContent(String templateDirectory, String templateName, Map<String, Object> paramMap) throws Exception {Configuration configuration = new Configuration(Configuration.DEFAULT_INCOMPATIBLE_IMPROVEMENTS);//不兼容配置try {configuration.setTemplateLoader(new ClassTemplateLoader(GetHtmlContent.class, templateDirectory));
//            configuration.setDirectoryForTemplateLoading(new File(templateDirectory));//加载模板} catch (Exception e) {e.printStackTrace();}Writer out = new StringWriter();Template template = configuration.getTemplate(templateName, "UTF-8");//缓存template.process(paramMap, out);out.flush();out.close();return out.toString();}}

2.1 test.html模板

<!DOCTYPE html>
<html lang="en">
<head><meta charset="UTF-8"/><title>测试表单</title><style>body {font-family: SimSun;}.f-s-1 {font-size: 12px;}.table-main {width: 100%;border-collapse: collapse;border-right: 1px solid rgba(0, 0, 0, 0.7);border-bottom: 1px solid rgba(0, 0, 0, 0.7);margin-bottom: 30px;}.table-main td {border-left: 1px solid rgba(0, 0, 0, 0.7);border-top: 1px solid rgba(0, 0, 0, 0.7);padding: 4px;}.th1 {font-weight: bold;background-color: #d7d7d7;}.th2 {background-color: #f1f1f1;}.text-center{text-align: center;}</style>
</head>
<body><h5 style="margin-top: 30px">学生列表</h5>
<table class="table-main f-s-1"><thead><tr><td class="th1" style="width: 28%">姓名</td><td class="th1 text-center" style="width: 12%">性别</td><td class="th1 text-center" style="width: 12%">年龄</td><td class="th1 text-center" style="width: 12%">地址</td></tr></thead><tbody><#list resultItems as item><tr><td class="text-center">${item.name}</td><td class="text-center">${item.sex}</td><td class="text-center">${item.age}</td><td class="text-center">${item.address}</td></tr></#list></tbody>
</table></body>
</html>

2.2 test.html模板中的Freemark语法

1、 <#list resultItems as item> 表示遍历后台返回的resultItems
2、下面判断age字段是否为空。

<#if age?? >存在<#else >不存在
</#if>

<#--判断数据是否存在，存在则则遍历-->
<#if resultItems??><#list resultItems as item>${item}</#list>
</#if>

3、controller导出pdf

注意: 代码中设置的变量要和html模板中的变量一致。

package cn.yx.zg.controller;import cn.yx.zg.utils.pdf.GeneratePDF;
import cn.yx.zg.utils.pdf.GetHtmlContent;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;import javax.servlet.http.HttpServletResponse;
import java.io.OutputStream;
import java.nio.charset.StandardCharsets;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;@RestController
public class TestExportPdfController {@RequestMapping("/test")public void test(HttpServletResponse response) throws Exception {Map<String, Object> paramMap = new HashMap<>();List<Map<String, Object>> resultItems = new ArrayList<>();for (int i = 0; i < 100; i++) {Map<String, Object> items = new HashMap<>();items.put("name", "张三" + i);items.put("age", "18" + i);items.put("sex", "男" + i);items.put("address", "河南" + i);resultItems.add(items);}paramMap.put("resultItems", resultItems);String destFileName = "测试表单.pdf";destFileName = new String(destFileName.getBytes(), StandardCharsets.ISO_8859_1);OutputStream out;//设置响应response.setHeader("Content-Disposition", "attachment;filename=" + destFileName);response.setContentType("application/pdf");out = response.getOutputStream();String templateContent = GetHtmlContent.getTemplateContent(GeneratePDF.TEMPLATE_DIRECTORY_INSPECTION, GeneratePDF.TEMPLATE_NAME_INSPECTION, paramMap);GeneratePDF.html2Pdf(templateContent, out);out.flush();}
}