构建工程
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。
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
|
<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>
|
创建文件上传controller
直接贴代码:
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
|
@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。
- GET / 获取已经上传的文件列表
- GET /files/{filename} 下载已经存在于服务器的文件
- POST / 上传文件给服务器
创建一个简单的 html模板
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
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
|
<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> |
上传文件大小限制
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:
1
2
|
spring.http.multipart.max-file-size=128KB spring.http.multipart.max-request-size=128KB |