SpringBoot + LibreOffice + Hutool 实现附件预览简单示例

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mob604756f1c0ca 2021-10-14 12:56:00

文章标签 附件预览 spring xml html maven 文章分类 办公效率

1. 简介

在日常开发中，经常会遇到需要预览附件的需求，如果附件类型为图片、文本、PDF或者网页文件，则直接可以在浏览器预览；如果附件类型为Word、Excel、PPT等文件，则需要通过工具转换为PDF后在浏览器预览。

本博客使用LibreOffice和Hutool实现文件预览简单示例。

LibreOffice官网：https://zh-cn.libreoffice.org/

2. 安装Libreoffice

Windows安装

下载介质：https://zh-cn.libreoffice.org/download/libreoffice/
安装时依次点击下一步即可（注意记录安装目录，在项目配置文件中需要配置）

Linux安装

yum安装

yum -y install libreoffice
# 安装后的目录为：/usr/lib64/libreoffice

乱码问题

# 上传Windows的C:\Windows\Fonts目录中的字体到Linux的/usr/share/fonts/windows目录
# 执行授权
chmod 644 /usr/share/fonts/windows/* && fc-cache -fv

官网安装手册
https://zh-cn.libreoffice.org/get-help/install-howto/

3. 示例代码

创建工程
修改pom.xml

<project xmlns="http://maven.apache.org/POM/4.0.0"
  xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
  xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd">
  <modelVersion>4.0.0</modelVersion>
  <groupId>com.c3stones</groupId>
  <artifactId>spring-boot-libreoffice-demo</artifactId>
  <version>0.0.1-SNAPSHOT</version>
  <name>spring-boot-libreoffice-demo</name>
  <description>Spring Boot Libreoffice Demo</description>

  <parent>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-parent</artifactId>
    <version>2.3.4.RELEASE</version>
    <relativePath />
  </parent>

  <dependencies>
    <dependency>
      <groupId>org.jodconverter</groupId>
      <artifactId>jodconverter-spring-boot-starter</artifactId>
      <version>4.4.2</version>
    </dependency>
    <dependency>
      <groupId>org.jodconverter</groupId>
      <artifactId>jodconverter-local</artifactId>
      <version>4.4.2</version>
    </dependency>
    <dependency>
      <groupId>org.jodconverter</groupId>
      <artifactId>jodconverter-core</artifactId>
      <version>4.4.2</version>
    </dependency>
    <dependency>
      <groupId>org.libreoffice</groupId>
      <artifactId>ridl</artifactId>
      <version>7.2.0</version>
    </dependency>
    <dependency>
      <groupId>cn.hutool</groupId>
      <artifactId>hutool-all</artifactId>
      <version>5.7.13</version>
    </dependency>
    <dependency>
      <groupId>org.springframework.boot</groupId>
      <artifactId>spring-boot-starter-thymeleaf</artifactId>
    </dependency>
    <dependency>
      <groupId>org.springframework.boot</groupId>
      <artifactId>spring-boot-starter-web</artifactId>
    </dependency>
  </dependencies>

  <build>
    <plugins>
      <plugin>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-maven-plugin</artifactId>
      </plugin>
    </plugins>
  </build>

</project>

创建配置文件application.yml

server:
  port: 8080

spring:
  thymeleaf:
    prefix: classpath:/view/
    suffix: .html
    encoding: UTF-8
    servlet:
      content-type: text/html
    cache: false
  servlet:
    multipart:
      max-file-size: 50MB
      max-request-size: 50MB

# 附件预览
jodconverter:
  local:
    enabled: true
#   # 设置LibreOffice目录
    officeHome: D:\LibreOffice
#   # CentOS 下安装 LibreOffice：
#   # 1、安装：yum -y install libreoffice
#   # 2、配置：officeHome: /usr/lib64/libreoffice
#   # Linux 中文字体乱码解决：
#   # 1、上传 C:\Windows\Fonts 下的字体到 /usr/share/fonts/windows 目录
#   # 2、执行命令： chmod 644 /usr/share/fonts/windows/* && fc-cache -fv
#   # 监听端口,开启多个LibreOffice进程，每个端口对应一个进程
#   portNumbers: 8100,8101,8102
    portNumbers: 2002
#   # LibreOffice进程重启前的最大进程数
    maxTasksPerProcess: 10
#   # 任务在转换队列中的最大生存时间，默认30s
    taskQueueTimeout: 30

创建Controller

import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;

import javax.servlet.http.HttpServletResponse;

import org.apache.tomcat.util.http.fileupload.IOUtils;
import org.jodconverter.core.DocumentConverter;
import org.jodconverter.core.office.OfficeException;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.ResponseBody;
import org.springframework.web.multipart.MultipartFile;

import cn.hutool.core.io.IORuntimeException;
import cn.hutool.core.io.IoUtil;
import cn.hutool.core.util.StrUtil;

/**
 * 附件预览Controller
 * 
 * @author CL
 *
 */
@Controller
@RequestMapping(value = "/file")
public class FilePreviewController {

  private static final Logger log = LoggerFactory.getLogger(FilePreviewController.class);

  @Autowired
  private DocumentConverter documentConverter;

  /**
   * 跳转到附件预览和下载页面
   * 
   * @return
   */
  @RequestMapping(value = "")
  public String index() {
    return "fileIndex";
  }

  /**
   * 附件预览
   * 
   * @param file     附件
   * @param response
   */
  @RequestMapping(value = "/preview")
  @ResponseBody
  public void preview(MultipartFile file, HttpServletResponse response) {
    if (file == null) {
      return;
    }
    InputStream inputStream = null;
    OutputStream outputStream = null;
    try {
      inputStream = file.getInputStream();
      outputStream = response.getOutputStream();
      String fileName = file.getOriginalFilename();
      if (StrUtil.endWithAnyIgnoreCase(fileName, ".doc", ".docx", ".xls", ".xlsx", ".csv", ".ppt", ".pptx")) {
        // 转为PDF
        documentConverter.convert(inputStream).to(outputStream)
            .as(documentConverter.getFormatRegistry().getFormatByExtension("pdf")).execute();
      } else if (StrUtil.endWithAnyIgnoreCase(fileName, ".pdf", ".txt", ".xml", ".md", ".json", ".html", ".htm",
          ".gif", ".jpg", ".jpeg", ".png", ".ico", ".bmp")) {
        IoUtil.copy(inputStream, outputStream);
      } else {
        outputStream.write("暂不支持预览此类型附件".getBytes());
      }
    } catch (IORuntimeException e) {
      log.error("附件预览IO运行异常：{}", e.getMessage());
    } catch (IOException e) {
      log.error("附件预览IO异常：{}", e.getMessage());
    } catch (OfficeException e) {
      log.error("附件预览Office异常：{}", e.getMessage());
    } finally {
      IOUtils.closeQuietly(inputStream);
    }
    IoUtil.writeUtf8(outputStream, true);
  }

}

创建附件预览示例页面
在resources下新建目录view，在view目录下新建页面：fileIndex.html。

<html>
<head>
  <title>附件预览和下载</title>
</head>
<body>
  <h5>支持附件类型为：.doc, .docx, .xls, .xlsx, .csv, .ppt, .pptx, .pdf, .txt, .xml, .md, .json, .gif, .jpg, .jpeg, .png, .ico, .bmp</h5>
  <form id="fileForm" action="" method="post" enctype="multipart/form-data">
    <i style="color: red">*</i> 上传附件：<input id="file" name="file" type="file" /><br/>
  </form>
  <button onclick="preview()">预览</button>
</body>
</html>
<script>
// 预览方法
function preview() {
  // 检查是否为空和大小限制
  var file = document.getElementById('file').files[0];
  if (!file) {
    alert("附件不能为空");
    return;
  }
  var fileSize = file.size;
  if (fileSize > 50 * 1024 * 1024) {
    alert("最大支持附件大小为 50MB");
    return;
  }

  // 提交表单
  var fileForm = document.getElementById('fileForm');
  fileForm.action = "[[@{/}]]file/preview";  
  fileForm.submit();
}
</script>

创建启动类

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;

/**
 * 启动类
 * 
 * @author CL
 *
 */
@SpringBootApplication
public class Application {

  public static void main(String[] args) {
    SpringApplication.run(Application.class, args);
  }

}