首先描述一下问题,spring boot 使用的是内嵌的tomcat, 所以不清楚文件上传到哪里去了, 而且spring boot 把静态的文件全部在启动的时候都会加载到classpath的目录下的,所以上传的文件不知相对于应用目录在哪,也不知怎么写访问路径合适,对于新手的自己真的一头雾水。
后面想起了官方的例子,没想到一开始被自己找到的官方例子,后面太依赖百度谷歌了,结果发现只有官方的例子能帮上忙,而且帮上大忙,直接上密码的代码
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
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
|
package hello; import static org.springframework.hateoas.mvc.ControllerLinkBuilder.linkTo; import static org.springframework.hateoas.mvc.ControllerLinkBuilder.methodOn; import java.io.IOException; import java.nio.file.Files; import java.nio.file.Paths; import java.util.stream.Collectors; import javax.servlet.http.HttpServletRequest; import org.slf4j.Logger; import org.slf4j.LoggerFactory; import org.springframework.beans.factory.annotation.Autowired; import org.springframework.core.io.ResourceLoader; import org.springframework.http.ResponseEntity; import org.springframework.stereotype.Controller; import org.springframework.ui.Model; import org.springframework.web.bind.annotation.PathVariable; import org.springframework.web.bind.annotation.RequestMapping; import org.springframework.web.bind.annotation.RequestMethod; import org.springframework.web.bind.annotation.RequestParam; import org.springframework.web.bind.annotation.ResponseBody; import org.springframework.web.multipart.MultipartFile; import org.springframework.web.servlet.mvc.support.RedirectAttributes; @Controller public class FileUploadController { private static final Logger log = LoggerFactory.getLogger(FileUploadController. class ); public static final String ROOT = "upload-dir" ; private final ResourceLoader resourceLoader; @Autowired public FileUploadController(ResourceLoader resourceLoader) { this .resourceLoader = resourceLoader; } @RequestMapping (method = RequestMethod.GET, value = "/" ) public String provideUploadInfo(Model model) throws IOException { model.addAttribute( "files" , Files.walk(Paths.get(ROOT)) .filter(path -> !path.equals(Paths.get(ROOT))) .map(path -> Paths.get(ROOT).relativize(path)) .map(path -> linkTo(methodOn(FileUploadController. class ).getFile(path.toString())).withRel(path.toString())) .collect(Collectors.toList())); return "uploadForm" ; } //显示图片的方法关键 匹配路径像 localhost:8080/b7c76eb3-5a67-4d41-ae5c-1642af3f8746.png @RequestMapping (method = RequestMethod.GET, value = "/{filename:.+}" ) @ResponseBody public ResponseEntity<?> getFile( @PathVariable String filename) { try { return ResponseEntity.ok(resourceLoader.getResource( "file:" + Paths.get(ROOT, filename).toString())); } catch (Exception e) { return ResponseEntity.notFound().build(); } } <strong> //上传的方法</strong> @RequestMapping (method = RequestMethod.POST, value = "/" ) public String handleFileUpload( @RequestParam ( "file" ) MultipartFile file, RedirectAttributes redirectAttributes, HttpServletRequest request) { System.out.println(request.getParameter( "member" )); if (!file.isEmpty()) { try { Files.copy(file.getInputStream(), Paths.get(ROOT, file.getOriginalFilename())); redirectAttributes.addFlashAttribute( "message" , "You successfully uploaded " + file.getOriginalFilename() + "!" ); } catch (IOException|RuntimeException e) { redirectAttributes.addFlashAttribute( "message" , "Failued to upload " + file.getOriginalFilename() + " => " + e.getMessage()); } } else { redirectAttributes.addFlashAttribute( "message" , "Failed to upload " + file.getOriginalFilename() + " because it was empty" ); } return "redirect:/" ; } } |
看完上面的代码可以理解到spring boot 的存取文件思路了,存的时候的路径为
1
|
Paths.get(ROOT, filename).toString())) |
这个路径会在本地的工程根目录上创建,不应用部署里的目录,所以一般的访问http访问不可能 ,所以它提供了ResourceLoader,利于这个类可以加载非应用目录的里文件然后返回
所以就可以读取文件,所以就要写getFIle方法来显示图片
如果大家对spring boot不是很了解,大家可以参考下面两篇文章。
以上所述是小编给大家介绍的spring boot 图片上传与显示功能实例详解,希望对大家有所帮助,如果大家有任何疑问请给我留言,小编会及时回复大家的。在此也非常感谢大家对服务器之家网站的支持!
原文链接:http://blog.csdn.net/a625013/article/details/52414470