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pdfcreatePdf(content, dest);// 读取pdf并预览readPdf(response);}public  void createPdf(String content,String dest) throws IOException, DocumentException {// step 1Document document = new Document();// step 2PdfWriter writer = PdfWriter.getInstance(document, new FileOutputStream(dest));// step 3document.open();// step 4XMLWorkerFontProvider 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 5document.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！