SpringBoot文件上传下载

约定不等于承诺〃 2022-05-27 02:35 417阅读 0赞

项目中经常会有上传和下载的需求，这篇文章简述一下springboot项目中实现简单的上传和下载。

新建springboot项目，前台页面使用的thymeleaf模板，其余的没有特别的配置，pom代码如下：

  1. <?xml version="1.0" encoding="UTF-8"?>
  2. <project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
  3.     xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
  4.     <modelVersion>4.0.0</modelVersion>
  6.     <groupId>com.dalaoyang</groupId>
  7.     <artifactId>springboot_upload_download</artifactId>
  8.     <version>0.0.1-SNAPSHOT</version>
  9.     <packaging>jar</packaging>
  11.     <name>springboot_upload_download</name>
  12.     <description>springboot_upload_download</description>
  14.     <parent>
  15.         <groupId>org.springframework.boot</groupId>
  16.         <artifactId>spring-boot-starter-parent</artifactId>
  17.         <version>1.5.9.RELEASE</version>
  18.         <relativePath/> <!-- lookup parent from repository -->
  19.     </parent>
  21.     <properties>
  22.         <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
  23.         <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
  24.         <java.version>1.8</java.version>
  25.     </properties>
  27.     <dependencies>
  28.         <dependency>
  29.             <groupId>org.springframework.boot</groupId>
  30.             <artifactId>spring-boot-starter-thymeleaf</artifactId>
  31.         </dependency>
  32.         <dependency>
  33.             <groupId>org.springframework.boot</groupId>
  34.             <artifactId>spring-boot-starter-web</artifactId>
  35.         </dependency>
  37.         <dependency>
  38.             <groupId>org.springframework.boot</groupId>
  39.             <artifactId>spring-boot-devtools</artifactId>
  40.             <scope>runtime</scope>
  41.         </dependency>
  42.         <dependency>
  43.             <groupId>org.springframework.boot</groupId>
  44.             <artifactId>spring-boot-starter-test</artifactId>
  45.             <scope>test</scope>
  46.         </dependency>
  48.         <dependency>
  49.             <groupId>net.sourceforge.nekohtml</groupId>
  50.             <artifactId>nekohtml</artifactId>
  51.             <version>1.9.15</version>
  52.         </dependency>
  53.     </dependencies>
  55.     <build>
  56.         <plugins>
  57.             <plugin>
  58.                 <groupId>org.springframework.boot</groupId>
  59.                 <artifactId>spring-boot-maven-plugin</artifactId>
  60.             </plugin>
  61.         </plugins>
  62.     </build>
  65. </project>

前台页面index.html，其中包含单个上传，下载，批量上传。

  1. <!DOCTYPE html>
  2. <html lang="en">
  3. <head>
  4.     <meta charset="UTF-8">
  5.     <title>Title</title>
  6. </head>
  7. <body>
  8. <p>单文件上传</p>
  9. <form action="upload" method="POST" enctype="multipart/form-data">
  10.     文件：<input type="file" name="file"/>
  11.     <input type="submit"/>
  12. </form>
  13. <hr/>
  14. <p>文件下载</p>
  15. <a href="download">下载文件</a>
  16. <hr/>
  17. <p>多文件上传</p>
  18. <form method="POST" enctype="multipart/form-data" action="batch">
  19.     <p>文件1：<input type="file" name="file"/></p>
  20.     <p>文件2：<input type="file" name="file"/></p>
  21.     <p><input type="submit" value="上传"/></p>
  22. </form>
  23. </body>
  24. </html>

IndexController只是用来页面的跳转

  1. package com.dalaoyang.Controller;
  3. import org.springframework.stereotype.Controller;
  4. import org.springframework.web.bind.annotation.GetMapping;
  5. import org.springframework.web.bind.annotation.RequestMapping;
  7. /**
  8.  * @author dalaoyang
  9.  * @Description
  10.  * @project springboot_learn
  11.  * @package com.dalaoyang.Controller
  12.  * @email yangyang@dalaoyang.cn
  13.  * @date 2018/4/9
  14.  */
  15. @Controller
  16. public class IndexController {
  18.     @RequestMapping("/")
  19.     public String index()
  20.     {
  21.         return "index";
  22.     }
  23. }

最后是本文的重点，FileController，其中包含单个上传，单个下载，批量上传对应的方法。需要注意下载功能写的是对应我电脑里面固定位置的文件，仅供大家来参考。以下是代码：

  1. package com.dalaoyang.Controller;
  3. import org.slf4j.Logger;
  4. import org.slf4j.LoggerFactory;
  5. import org.springframework.web.bind.annotation.*;
  6. import org.springframework.web.multipart.MultipartFile;
  7. import org.springframework.web.multipart.MultipartHttpServletRequest;
  8. import javax.servlet.http.HttpServletRequest;
  9. import javax.servlet.http.HttpServletResponse;
  10. import java.io.*;
  11. import java.util.List;
  14. /**
  15.  * @author dalaoyang
  16.  * @Description
  17.  * @project springboot_learn
  18.  * @package com.dalaoyang.Controller
  19.  * @email yangyang@dalaoyang.cn
  20.  * @date 2018/4/9
  21.  */
  22. @RestController
  23. public class FileController {
  24.     private static final Logger log = LoggerFactory.getLogger(FileController.class);
  26.     @RequestMapping(value = "/upload")
  27.     public String upload(@RequestParam("file") MultipartFile file) {
  28.         try {
  29.             if (file.isEmpty()) {
  30.                 return "文件为空";
  31.             }
  32.             // 获取文件名
  33.             String fileName = file.getOriginalFilename();
  34.             log.info("上传的文件名为：" + fileName);
  35.             // 获取文件的后缀名
  36.             String suffixName = fileName.substring(fileName.lastIndexOf("."));
  37.             log.info("文件的后缀名为：" + suffixName);
  38.             // 设置文件存储路径
  39.             String filePath = "/Users/dalaoyang/Downloads/";
  40.             String path = filePath + fileName;
  41.             File dest = new File(path);
  42.             // 检测是否存在目录
  43.             if (!dest.getParentFile().exists()) {
  44.                 dest.getParentFile().mkdirs();// 新建文件夹
  45.             }
  46.             file.transferTo(dest);// 文件写入
  47.             return "上传成功";
  48.         } catch (IllegalStateException e) {
  49.             e.printStackTrace();
  50.         } catch (IOException e) {
  51.             e.printStackTrace();
  52.         }
  53.         return "上传失败";
  54.     }
  56.     @PostMapping("/batch")
  57.     public String handleFileUpload(HttpServletRequest request) {
  58.         List<MultipartFile> files = ((MultipartHttpServletRequest) request).getFiles("file");
  59.         MultipartFile file = null;
  60.         BufferedOutputStream stream = null;
  61.         for (int i = 0; i < files.size(); ++i) {
  62.             file = files.get(i);
  63.             String filePath = "/Users/dalaoyang/Downloads/";
  64.             if (!file.isEmpty()) {
  65.                 try {
  66.                     byte[] bytes = file.getBytes();
  67.                     stream = new BufferedOutputStream(new FileOutputStream(
  68.                             new File(filePath + file.getOriginalFilename())));//设置文件路径及名字
  69.                     stream.write(bytes);// 写入
  70.                     stream.close();
  71.                 } catch (Exception e) {
  72.                     stream = null;
  73.                     return "第 " + i + " 个文件上传失败 ==> "
  74.                             + e.getMessage();
  75.                 }
  76.             } else {
  77.                 return "第 " + i
  78.                         + " 个文件上传失败因为文件为空";
  79.             }
  80.         }
  81.         return "上传成功";
  82.     }
  84.     @GetMapping("/download")
  85.     public String downloadFile(HttpServletRequest request, HttpServletResponse response) {
  86.         String fileName = "dalaoyang.jpeg";// 文件名
  87.         if (fileName != null) {
  88.             //设置文件路径
  89.             File file = new File("/Users/dalaoyang/Documents/dalaoyang.jpeg");
  90.             //File file = new File(realPath , fileName);
  91.             if (file.exists()) {
  92.                 response.setContentType("application/force-download");// 设置强制下载不打开
  93.                 response.addHeader("Content-Disposition", "attachment;fileName=" + fileName);// 设置文件名
  94.                 byte[] buffer = new byte[1024];
  95.                 FileInputStream fis = null;
  96.                 BufferedInputStream bis = null;
  97.                 try {
  98.                     fis = new FileInputStream(file);
  99.                     bis = new BufferedInputStream(fis);
  100.                     OutputStream os = response.getOutputStream();
  101.                     int i = bis.read(buffer);
  102.                     while (i != -1) {
  103.                         os.write(buffer, 0, i);
  104.                         i = bis.read(buffer);
  105.                     }
  106.                     return "下载成功";
  107.                 } catch (Exception e) {
  108.                     e.printStackTrace();
  109.                 } finally {
  110.                     if (bis != null) {
  111.                         try {
  112.                             bis.close();
  113.                         } catch (IOException e) {
  114.                             e.printStackTrace();
  115.                         }
  116.                     }
  117.                     if (fis != null) {
  118.                         try {
  119.                             fis.close();
  120.                         } catch (IOException e) {
  121.                             e.printStackTrace();
  122.                         }
  123.                     }
  124.                 }
  125.             }
  126.         }
  127.         return "下载失败";
  128.     }
  129. }

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