使用 Spring Boot 和 Thymeleaf 上传文件
Spring Boot 利用 MultipartFile 的特性来接收和处理上传的文件，本示例前端页面使用 Thymeleaf 来处理。
快速上手:
1、添加依赖包
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-thymeleaf</artifactId>
</dependency>
2、application.properties配置信息
#支持的最大文件 spring.servlet.multipart.max-file-size=100MB #文件请求最大限制 spring.servlet.multipart.max-request-size=100MB
#除过以上配置，常用的配置信息如下：
spring.servlet.multipart.enabled=true，是否支持 multipart 上传文件
spring.servlet.multipart.file-size-threshold=0，支持文件写入磁盘
spring.servlet.multipart.location=，上传文件的临时目录
spring.servlet.multipart.max-file-size=10Mb，最大支持文件大小
spring.servlet.multipart.max-request-sizee=10Mb，最大支持请求大小
spring.servlet.multipart.resolve-lazily=false，是否支持 multipart 上传文件时懒加载
3、启动类
@SpringBootApplication public class FileUploadWebApplication { public static void main(String[] args) throws Exception { SpringApplication.run(FileUploadWebApplication.class, args); } //Tomcat large file upload connection reset @Bean public TomcatServletWebServerFactory tomcatEmbedded() { TomcatServletWebServerFactory tomcat = new TomcatServletWebServerFactory(); tomcat.addConnectorCustomizers((TomcatConnectorCustomizer) connector -> { if ((connector.getProtocolHandler() instanceof AbstractHttp11Protocol<?>)) { //-1 means unlimited ((AbstractHttp11Protocol<?>) connector.getProtocolHandler()).setMaxSwallowSize(-1); } }); return tomcat; } }
TomcatServletWebServerFactory() 方法主要是为了解决上传文件大于 10M 出现连接重置的问题
4、简单前端页面:
单个文件上传页面 upload.html:
<!DOCTYPE html> <html xmlns:th="http://www.thymeleaf.org"> <body> <h1>Spring Boot file upload example</h1> <form method="POST" action="/upload" enctype="multipart/form-data"> <input type="file" name="file" /><br/><br/> <input type="submit" value="Submit" /> </form> </body> </html>
多个文件上传页面 uploadMore.html:
<!DOCTYPE html> <html xmlns:th="http://www.thymeleaf.org"> <body> <h1>Spring Boot files upload example</h1> <form method="POST" action="/uploadMore" enctype="multipart/form-data"> <input type="file" name="file" /><br/><br/> <input type="file" name="file" /><br/><br/> <input type="file" name="file" /><br/><br/> <input type="submit" value="Submit" /> </form> </body> </html>
上传结果页面：uploadStatus.html
<!DOCTYPE html> <html lang="en" xmlns:th="http://www.thymeleaf.org"> <body> <h1>Spring Boot - Upload Status</h1> <div th:if="${message}"> <h2 th:text="${message}"/> </div> </body> </html>
5、后台上传控制类
@Controller public class UploadController { //文件存储目录 private String UPLOAD_PATH="E://temp//"; //跳转上传页面 @RequestMapping("/") public String index() { return "upload"; } @GetMapping("/more") public String uploadMore() { return "uploadMore"; } //多个文件上传 @RequestMapping("/uploadMore") public String moreFileUpload(@RequestParam("file") MultipartFile[] files,RedirectAttributes redirectAttrs) { if(files.length ==0) { redirectAttrs.addFlashAttribute("message", "Please select a file to upload"); return "redirect:uploadStatus"; } for(MultipartFile file :files) { try { byte[] bytes = file.getBytes(); Path path = Paths.get(UPLOAD_PATH+file.getOriginalFilename()); Files.write(path, bytes); } catch (IOException e) { e.printStackTrace(); } } redirectAttrs.addFlashAttribute("message", "You successfully uploaded all files"); return "redirect:/uploadStatus"; } //单个文件上传 @PostMapping("/upload") public String singleFileUpload(@RequestParam("file") MultipartFile file,RedirectAttributes redirectAttrs) { if(file.isEmpty()) { redirectAttrs.addFlashAttribute("message", "Please select a file to upload"); return "redirect:uploadStatus"; } try { byte[] bytes = file.getBytes(); Path path = Paths.get(UPLOAD_PATH+file.getOriginalFilename()); Files.write(path, bytes); redirectAttrs.addFlashAttribute("message", "You successfully uploaded '" + file.getOriginalFilename() + "'"); } catch (IOException e) { e.printStackTrace(); } return "redirect:/uploadStatus"; } //跳转结果页面 @RequestMapping("/uploadStatus") public String uploadStatus() { return "uploadStatus"; } }
6、运行启动类：FileUploadWebApplication
在浏览器访问：
多个文件上传：
OK ，上传成功。