初夏 - 云代码空间
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这篇文章主要介绍，如何在springboot工程作为服务器，去接收通过http 上传的multi-file的文件。
为例创建一个springmvc工程你需要spring-boot-starter-thymeleaf和 spring-boot-starter-web的起步依赖。为例能够上传文件在服务器，你需要在web.xml中加入标签做相关的配置，但在sringboot 工程中，它已经为你自动做了，所以不需要你做任何的配置。
<dependencies>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</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-thymeleaf</artifactId>
</dependency>
</dependencies>
直接贴代码：
@Controller public class FileUploadController { private final StorageService storageService; @Autowired public FileUploadController(StorageService storageService) { this.storageService = storageService; } @GetMapping("/") public String listUploadedFiles(Model model) throws IOException { model.addAttribute("files", storageService .loadAll() .map(path -> MvcUriComponentsBuilder .fromMethodName(FileUploadController.class, "serveFile", path.getFileName().toString()) .build().toString()) .collect(Collectors.toList())); return "uploadForm"; } @GetMapping("/files/{filename:.+}") @ResponseBody public ResponseEntity<Resource> serveFile(@PathVariable String filename) { Resource file = storageService.loadAsResource(filename); return ResponseEntity .ok() .header(HttpHeaders.CONTENT_DISPOSITION, "attachment; filename=\""+file.getFilename()+"\"") .body(file); } @PostMapping("/") public String handleFileUpload(@RequestParam("file") MultipartFile file, RedirectAttributes redirectAttributes) { storageService.store(file); redirectAttributes.addFlashAttribute("message", "You successfully uploaded " + file.getOriginalFilename() + "!"); return "redirect:/"; } @ExceptionHandler(StorageFileNotFoundException.class) public ResponseEntity handleStorageFileNotFound(StorageFileNotFoundException exc) { return ResponseEntity.notFound().build(); } }
这个类通过@Controller注解，表明自己上一个Spring mvc的c。每个方法通过
@GetMapping 或者@PostMapping注解表明自己的 http方法。
为了展示上传文件的过程，我们做一个界面：
在src/main/resources/templates/uploadForm.html
<html xmlns:th="http://www.thymeleaf.org">
<body>
<div th:if="${message}">
<h2 th:text="${message}"/>
</div>
<div>
<form method="POST" enctype="multipart/form-data" action="/">
<table>
<tr><td>File to upload:</td><td><input type="file" name="file" /></td></tr>
<tr><td></td><td><input type="submit" value="Upload" /></td></tr>
</table>
</form>
</div>
<div>
<ul>
<li th:each="file : ${files}">
<a th:href="${file}" th:text="${file}" />
</li>
</ul>
</div>
</body>
</html>
如果需要限制上传文件的大小也很简单，只需要在springboot 工程的src/main/resources/application.properties 加入以下：
spring.http.multipart.max-file-size=128KB
spring.http.multipart.max-request-size=128KB
