springboot文件上传下载到本机服务器上
这次的文件上传下载仅指的是本机的服务器，不指第三方文件存储系统！！！
1.在pom中加入以下依赖，如已经加入，请忽略
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-thymeleaf</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
</dependency>2.创建controller
@Controller
@RequestMapping("/fileUpload")
public class FileUploadController {
private final StorageService storageService;
@Autowired
public FileUploadController(StorageService storageService) {
this.storageService = storageService;
}
@GetMapping("/form")
public String listUploadedFiles(Model model) throws IOException {
model.addAttribute("files", storageService.loadAll().map(
path -> MvcUriComponentsBuilder.fromMethodName(FileUploadController.class,
"serveFile", path.getFileName().toString()).build().toUri().toString())
.collect(Collectors.toList()));
return "uploadForm";
}
@GetMapping("/files/{filename:.+}")
@ResponseBody
public ResponseEntity<Resource> serveFile(@PathVariable String filename) {
Resource file = storageService.loadAsResource(filename);
if (file == null)
return ResponseEntity.notFound().build();
return ResponseEntity.ok().header(HttpHeaders.CONTENT_DISPOSITION,
"attachment; filename=\"" + file.getFilename() + "\"").body(file);
}
@PostMapping("/handleFileUpload")
public String handleFileUpload(@RequestParam("file") MultipartFile file,
RedirectAttributes redirectAttributes) {
storageService.store(file);
redirectAttributes.addFlashAttribute("message",
"You successfully uploaded " + file.getOriginalFilename() + "!");
return "redirect:/fileUpload/form";
}
@ExceptionHandler(StorageFileNotFoundException.class)
public ResponseEntity<?> handleStorageFileNotFound(StorageFileNotFoundException exc) {
return ResponseEntity.notFound().build();
}
}3.加入以下类
@Service
public class FileSystemStorageService implements StorageService {
private final Path rootLocation;
@Autowired
public FileSystemStorageService(StorageProperties properties) {
if (properties.getLocation().trim().length() == 0) {
throw new StorageException("File upload location can not be Empty.");
}
this.rootLocation = Paths.get(properties.getLocation());
}
@Override
public void store(MultipartFile file) {
try {
if (file.isEmpty()) {
throw new StorageException("Failed to store empty file.");
}
Path destinationFile = this.rootLocation.resolve(
Paths.get(file.getOriginalFilename()))
.normalize().toAbsolutePath();
if (!destinationFile.getParent().equals(this.rootLocation.toAbsolutePath())) {
// This is a security check
throw new StorageException(
"Cannot store file outside current directory.");
}
try (InputStream inputStream = file.getInputStream()) {
Files.copy(inputStream, destinationFile,
StandardCopyOption.REPLACE_EXISTING);
}
} catch (IOException e) {
throw new StorageException("Failed to store file.", e);
}
}
@Override
public Stream<Path> loadAll() {
try {
return Files.walk(this.rootLocation, 1)
.filter(path -> !path.equals(this.rootLocation))
.map(this.rootLocation::relativize);
} catch (IOException e) {
throw new StorageException("Failed to read stored files", e);
}
}
@Override
public Path load(String filename) {
return rootLocation.resolve(filename);
}
@Override
public Resource loadAsResource(String filename) {
try {
Path file = load(filename);
Resource resource = new UrlResource(file.toUri());
if (resource.exists() || resource.isReadable()) {
return resource;
} else {
throw new StorageFileNotFoundException(
"Could not read file: " + filename);
}
} catch (MalformedURLException e) {
throw new StorageFileNotFoundException("Could not read file: " + filename, e);
}
}
@Override
public void deleteAll() {
FileSystemUtils.deleteRecursively(rootLocation.toFile());
}
@Override
public void init() {
try {
Files.createDirectories(rootLocation);
} catch (IOException e) {
throw new StorageException("Could not initialize storage", e);
}
}
}@ConfigurationProperties("storage")
public class StorageProperties {
/**
* Folder location for storing files
*/
private String location = "upload-dir";
public String getLocation() {
return location;
}
public void setLocation(String location) {
this.location = location;
}
}public interface StorageService {
void init();
void store(MultipartFile file);
Stream<Path> loadAll();
Path load(String filename);
Resource loadAsResource(String filename);
void deleteAll();
}public class StorageException extends RuntimeException {
public StorageException(String message) {
super(message);
}
public StorageException(String message, Throwable cause) {
super(message, cause);
}
}public class StorageFileNotFoundException extends StorageException {
public StorageFileNotFoundException(String message) {
super(message);
}
public StorageFileNotFoundException(String message, Throwable cause) {
super(message, cause);
}
}4.在resources里面加入templates,jiaru uploadForm.html
<html xmlns:th="https://www.thymeleaf.org">
<body>
<div th:if="${message}">
<h2 th:text="${message}"/>
</div>
<div>
<form method="POST" enctype="multipart/form-data" action="/Scaffold/fileUpload/handleFileUpload">
<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>5.在启动类里面加入
@SpringBootApplication
@EnableConfigurationProperties(StorageProperties.class)
public class UploadingFilesApplication {
public static void main(String[] args) {
SpringApplication.run(UploadingFilesApplication.class, args);
}
@Bean
CommandLineRunner init(StorageService storageService) {
return (args) -> {
storageService.deleteAll();
storageService.init();
};
}
}启动项目，开始测试
点击选择文件，选择文件之后，点击upload，会出现以下界面
点击蓝色的部分，就可以下载了，并且可以看到服务器这里就是上传的文件了
目前重启服务器，上传的文件就会删除掉了，如果不想删除掉的话，启动类里面的代码可以是去掉storageService.deleteAll();这一行代码，变成为：
@SpringBootApplication
@EnableConfigurationProperties(StorageProperties.class)
public class UploadingFilesApplication {
public static void main(String[] args) {
SpringApplication.run(UploadingFilesApplication.class, args);
}
@Bean
CommandLineRunner init(StorageService storageService) {
return (args) -> {
storageService.init();
};
}
}可以在application.properties里加入对文件大小的控制
#文件上传
spring.servlet.multipart.max-file-size=500KB
spring.servlet.multipart.max-request-size=500KB这里还有一个问题，上传的word下载不乱吗，但图片，PPT，Excel均乱码，对于这个的乱码问题要做进一步的处理，现在先不处理，以后处理之后再更新
