SpringBoot(十五)_springboot实现预览pdf

最近，项目上要做个打印的东西，还要预览。我想就直接生成pdf预览，然后用户选择打印

于是，昨天找了找资料。一般用itext 进行转pdf。于是我就用springboot试了试，代码比较简单，现在只是简单的一个实现。

整体流程如下

• 1.获取数据（比如从数据库获取数据）
• 2.通过freemarker 渲染页面
• 3.将渲染的页面进行转换为pdf，放在本地
• 4.读取pdf，实现预览

主要代码

pom文件

<dependencies> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-freemarker</artifactId> </dependency> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-test</artifactId> <scope>test</scope> </dependency> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-web</artifactId> <version>RELEASE</version> <scope>compile</scope> </dependency> <!-- https://mvnrepository.com/artifact/com.itextpdf/itextpdf --> <dependency> <groupId>com.itextpdf</groupId> <artifactId>itextpdf</artifactId> <version>5.5.13</version> </dependency> <!-- https://mvnrepository.com/artifact/com.itextpdf.tool/xmlworker --> <dependency> <groupId>com.itextpdf.tool</groupId> <artifactId>xmlworker</artifactId> <version>5.5.13</version> </dependency> <dependency> <groupId>commons-io</groupId> <artifactId>commons-io</artifactId> <version>2.5</version> </dependency> </dependencies>

PdfController代码

package com.kevin.pdf_demo.controller; import com.itextpdf.text.Document; import com.itextpdf.text.DocumentException; import com.itextpdf.text.pdf.PdfWriter; import com.itextpdf.tool.xml.XMLWorkerFontProvider; import com.itextpdf.tool.xml.XMLWorkerHelper; import freemarker.template.Configuration; import freemarker.template.Template; import org.apache.commons.io.IOUtils; import org.springframework.beans.factory.annotation.Value; import org.springframework.core.io.ClassPathResource; import org.springframework.web.bind.annotation.RequestMapping; import org.springframework.web.bind.annotation.RestController; import javax.servlet.http.HttpServletResponse; import java.io.*; import java.nio.charset.Charset; import java.util.HashMap; import java.util.Map; /** * @author: kevin * @Date: 2018/11/16 */ @RestController public class PdfController { @Value("${DEST}") private String dest; @Value("${HTML}") private String html; @Value("${FONT}") private String font; private static Configuration freemarkerCfg = null; @RequestMapping(value = "helloPdf") public void showPdf(HttpServletResponse response) throws IOException, DocumentException { //需要填充的数据 Map<String, Object> data = new HashMap<>(16); data.put("name", "kevin"); String content = freeMarkerRender(data,html); //创建pdf createPdf(content, dest); // 读取pdf并预览 readPdf(response); } public void createPdf(String content,String dest) throws IOException, DocumentException { // step 1 Document document = new Document(); // step 2 PdfWriter writer = PdfWriter.getInstance(document, new FileOutputStream(dest)); // step 3 document.open(); // step 4 XMLWorkerFontProvider fontImp = new XMLWorkerFontProvider(XMLWorkerFontProvider.DONTLOOKFORFONTS); fontImp.register(font); XMLWorkerHelper.getInstance().parseXHtml(writer, document, new ByteArrayInputStream(content.getBytes("UTF-8")), null, Charset.forName("UTF-8"), fontImp); // step 5 document.close(); } /** * freemarker渲染html */ public String freeMarkerRender(Map<String, Object> data, String htmlTmp) { Writer out = new StringWriter(); try { // 获取模板,并设置编码方式 setFreemarkerCfg(); Template template = freemarkerCfg.getTemplate(htmlTmp); template.setEncoding("UTF-8"); //将合并后的数据和模板写入到流中，这里使用的字符流 template.process(data, out); out.flush(); return out.toString(); } catch (Exception e) { e.printStackTrace(); } finally { try { out.close(); } catch (IOException ex) { ex.printStackTrace(); } } return null; } /** * 设置freemarkerCfg */ private void setFreemarkerCfg() { freemarkerCfg = new Configuration(); //freemarker的模板目录 try { freemarkerCfg.setDirectoryForTemplateLoading(new ClassPathResource("template").getFile()); } catch (IOException e) { e.printStackTrace(); } } /** * 读取本地pdf,这里设置的是预览 */ private void readPdf(HttpServletResponse response) { response.reset(); response.setContentType("application/pdf"); try { File file = new File(dest); FileInputStream fileInputStream = new FileInputStream(file); OutputStream outputStream = response.getOutputStream(); IOUtils.write(IOUtils.toByteArray(fileInputStream), outputStream); response.setHeader("Content-Disposition", "inline; filename= file"); outputStream.flush(); } catch (FileNotFoundException e) { e.printStackTrace(); } catch (IOException e) { e.printStackTrace(); } } } 

运行效果

设置头信息使浏览器下载文件或预览

强制浏览器下载

response.setHeader("content-disposition", "attachment;filename=" + realName);

浏览器尝试打开,支持office online或浏览器预览pdf功能

response.setHeader("content-disposition", "inline;filename=" + realName);

完整代码 : github

玩的开心！