Java Spring Cloud B2B2C o2o Multi-user Mall Spring cloud Architecture Upload Files

Keywords: Programming Spring Java Thymeleaf SpringBoot

This article mainly introduces how to use springboot project as a server to receive multi-file files uploaded through http.

Construction project

For example, to create a spring MVC project, you need spring-boot-starter-thymeleaf and spring-boot-starter-web start dependencies. For example, to upload files to the server, you need to add tags to the web.xml to configure it, but in the sringboot project, it has been done automatically for you, so you don't 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

Paste code directly:

@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 annotates its last Spring mvc c C with the @Controller annotation. Each method passes
@ The GetMapping or @PostMapping annotations indicate their own http methods.

GET / Get the list of files that have been uploaded
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:
At 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 Limitation

If you need to limit the size of uploaded files, it's easy to add the following to the springboot project's src/main/resources/application.properties:

spring.http.multipart.max-file-size=128KB
spring.http.multipart.max-request-size=128KB

The architecture code is as follows:

The source code of B2B2C e-commerce platform constructed by Spring Cloud distributed micro-service cloud for large enterprises, Please add Penguin: 10387474626

Posted by jscnet on Fri, 22 Mar 2019 09:21:53 -0700

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