Uploading files with Spring Boot and Angular

 1// src/main/java/dev/mflash/guides/upload/service/StorageService.java
 2
 3public interface StorageService {
 4
 5  void init();
 6
 7  void store(MultipartFile... files);
 8
 9  Stream<Path> loadAll();
10
11  void deleteAll();
12}

 1// src/main/java/dev/mflash/guides/upload/service/FileSystemStorageService.java
 2
 3public @Service class FileSystemStorageService implements StorageService {
 4
 5  private final Path rootDir;
 6
 7  public FileSystemStorageService(StorageProperties storageProperties) {
 8    this.rootDir = Paths.get(storageProperties.getLocation());
 9  }
10
11  public @Override void init() {
12    try {
13      Files.createDirectories(rootDir);
14    } catch (Exception e) {
15      throw new StorageException("Could not initialize storage", e);
16    }
17  }
18
19  public @Override void store(MultipartFile... files) {
20    if (files.length > 0) {
21      List.of(files).forEach(file -> {
22        String filename = StringUtils.cleanPath(Objects.requireNonNull(file.getOriginalFilename()));
23        try {
24          if (file.isEmpty()) {
25            throw new StorageException("Failed to store empty file " + filename);
26          }
27          if (filename.contains("..")) {
28            throw new StorageException("Cannot store file with relative path outside current directory " + filename);
29          }
30          try (InputStream inputStream = file.getInputStream()) {
31            Files.copy(inputStream, this.rootDir.resolve(filename), StandardCopyOption.REPLACE_EXISTING);
32          }
33        } catch (IOException e) {
34          throw new StorageException("Failed to store file " + filename, e);
35        }
36      });
37    } else {
38      throw new StorageException("Invalid request payload");
39    }
40  }
41
42  public @Override Stream<Path> loadAll() {
43    try {
44      return Files.walk(this.rootDir, 1)
45          .filter(path -> !path.equals(this.rootDir))
46          .map(this.rootDir::relativize);
47    } catch (IOException e) {
48      throw new StorageException("Failed to read stored files", e);
49    }
50  }
51
52  public @Override void deleteAll() {
53    FileSystemUtils.deleteRecursively(rootDir.toFile());
54  }
55}

 1// src/main/java/dev/mflash/guides/upload/controller/FileSystemStorageController.java
 2
 3@RequestMapping("/file")
 4public @RestController class FileSystemStorageController {
 5
 6  private final StorageService storageService;
 7
 8  public FileSystemStorageController(StorageService storageService) {
 9    this.storageService = storageService;
10  }
11
12  public @GetMapping List<Path> listAllFiles() {
13    return storageService.loadAll().collect(Collectors.toList());
14  }
15
16  public @PostMapping Map<String, String> uploadFile(@RequestParam("data") MultipartFile... file) {
17    try {
18      storageService.store(Objects.requireNonNull(file));
19      return Collections.singletonMap("status", "Successfully uploaded");
20    } catch (Exception e) {
21      return Collections.singletonMap("status", e.getLocalizedMessage());
22    }
23  }
24}

 1// src/main/java/dev/mflash/guides/upload/Launcher.java
 2
 3@EnableConfigurationProperties(StorageProperties.class)
 4public @SpringBootApplication class Launcher implements WebMvcConfigurer {
 5
 6  public static void main(String[] args) {
 7    SpringApplication.run(Launcher.class, args);
 8  }
 9
10  public @Override void addCorsMappings(CorsRegistry registry) {
11    registry.addMapping("/**").allowedOrigins("http://localhost:4200");
12  }
13}