Construction project
For example, to create a spring MVC project, you need the start dependency of spring boot starter thymeleaf and spring boot starter web. For example, if you can upload files to the server, you need to add tags to the web.xml to do the relevant configuration, but in the sringboot project, it has been done for you automatically, so you do not need to do any configuration.
<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>
Create file upload controller
Direct post code:
@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(); } }
This class uses @ Controller annotation to indicate the c of its last Spring mvc. Each method passes
@The GetMapping or @ PostMapping annotations indicate their own http methods.
- GET / GET the list of uploaded files
- GET /files/{filename} download files that already exist on the server
- POST / upload files to server
Create a simple html template
In order to show the process of uploading files, we make an interface:
In 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>
Upload file size limit
If you need to limit the size of the uploaded file, you only need to add the following in src/main/resources/application.properties of the springboot project:
spring.http.multipart.max-file-size=128KB spring.http.multipart.max-request-size=128KB
