SpringBoot(十五)_springboot实现预览pdf-白红宇

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


            
                 
      
       org.springframework.boot
                  
      
       spring-boot-starter-freemarker
              
             
                 
      
       org.springframework.boot
                  
      
       spring-boot-starter-test
                  
      
       test
              
             
                 
      
       org.springframework.boot
                  
      
       spring-boot-starter-web
                  
      
       RELEASE
                  
      
       compile
              
             
             
                 
      
       com.itextpdf
                  
      
       itextpdf
                  
      
       5.5.13
              
             
             
                 
      
       com.itextpdf.tool
                  
      
       xmlworker
                  
      
       5.5.13
              
             
                 
      
       commons-io
                  
      
       commons-io
                  
      
       2.5

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 */@RestControllerpublic 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
    
      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
     
       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 :

玩的开心！