Add picture format control.

codiki-exposition/src/main/java/org/codiki/exposition/configuration/GlobalControllerExceptionHandler.java

@@ -2,6 +2,7 @@ package org.codiki.exposition.configuration;
 
 import static org.springframework.http.HttpStatus.BAD_REQUEST;
 import static org.springframework.http.HttpStatus.FORBIDDEN;
+import static org.springframework.http.HttpStatus.INTERNAL_SERVER_ERROR;
 import static org.springframework.http.HttpStatus.NOT_FOUND;
 import static org.springframework.http.HttpStatus.UNAUTHORIZED;
 import org.codiki.domain.category.exception.CategoryDeletionException;
@@ -11,6 +12,8 @@ import org.codiki.domain.exception.LoginFailureException;
 import org.codiki.domain.exception.RefreshTokenDoesNotExistException;
 import org.codiki.domain.exception.RefreshTokenExpiredException;
 import org.codiki.domain.exception.UserDoesNotExistException;
+import org.codiki.domain.picture.exception.PictureNotFoundException;
+import org.codiki.domain.picture.exception.PictureUploadException;
 import org.codiki.domain.publication.exception.PublicationEditionException;
 import org.codiki.domain.publication.exception.PublicationNotFoundException;
 import org.codiki.domain.publication.exception.PublicationUpdateForbiddenException;
@@ -80,4 +83,16 @@ public class GlobalControllerExceptionHandler {
     public void handleCategoryDeletionException() {
         // Do nothing.
     }
+
+    @ResponseStatus(BAD_REQUEST)
+    @ExceptionHandler(PictureUploadException.class)
+    public void handlePictureUploadException() {
+        // Do nothing.
+    }
+
+    @ResponseStatus(NOT_FOUND)
+    @ExceptionHandler(PictureNotFoundException.class)
+    public void handlePictureNotFoundException() {
+        // Do nothing.
+    }
 }

codiki-exposition/src/main/java/org/codiki/exposition/configuration/security/SecurityConfiguration.java

@@ -44,6 +44,7 @@ public class SecurityConfiguration {
                     GET,
                     "/api/health/check",
                     "/api/categories",
+                    "/api/pictures/{pictureId}",
                     "/error"
                 ).permitAll()
                 .requestMatchers(

codiki-exposition/src/main/java/org/codiki/exposition/picture/MultipartFileConverter.java

@@ -1,23 +1,44 @@
 package org.codiki.exposition.picture;
 
+import static java.util.Objects.isNull;
 import java.io.File;
 import java.io.IOException;
+import java.util.List;
 import java.util.UUID;
 
+import org.apache.tika.mime.MimeType;
+import org.apache.tika.mime.MimeTypeException;
+import org.apache.tika.mime.MimeTypes;
+import org.codiki.domain.picture.exception.PictureUploadException;
 import org.springframework.beans.factory.annotation.Value;
 import org.springframework.stereotype.Component;
 import org.springframework.web.multipart.MultipartFile;
 
 @Component
 public class MultipartFileConverter {
-    private final String tempPicturesForlderPath;
+    private static final List<MimeType> ALLOWED_MIME_TYPES;
 
-    public MultipartFileConverter(@Value("${application.pictures.temp-path}") String tempPicturesForlderPath) {
-        this.tempPicturesForlderPath = tempPicturesForlderPath;
+    static {
+        MimeTypes mimeTypes = MimeTypes.getDefaultMimeTypes();
+
+        try {
+            ALLOWED_MIME_TYPES = List.of(
+                mimeTypes.forName("image/png"),
+                mimeTypes.forName("image/jpeg")
+            );
+        } catch (MimeTypeException exception) {
+            throw new RuntimeException("An error occurred while loading allowed mime types.", exception);
+        }
+    }
+
+    private final String tempPicturesFolderPath;
+
+    public MultipartFileConverter(@Value("${application.pictures.temp-path}") String tempPicturesFolderPath) {
+        this.tempPicturesFolderPath = tempPicturesFolderPath;
     }
 
     public File transformToFile(MultipartFile fileContent) {
-        File pictureFile = new File(String.format("%s/%s", tempPicturesForlderPath, UUID.randomUUID()));
+        File pictureFile = new File(buildPicturePath(fileContent));
         try {
             fileContent.transferTo(pictureFile);
         } catch (IOException e) {
@@ -25,4 +46,34 @@ public class MultipartFileConverter {
         }
         return pictureFile;
     }
+
+    private String buildPicturePath(MultipartFile fileContent) {
+        MimeType fileContentType = extractMimeType(fileContent);
+        return String.format(
+            "%s/%s%s",
+            tempPicturesFolderPath,
+            UUID.randomUUID(),
+            fileContentType.getExtension()
+        );
+    }
+
+    private MimeType extractMimeType(MultipartFile fileContent) {
+        MimeType result = null;
+        try {
+            result = MimeTypes.getDefaultMimeTypes()
+                .forName(fileContent.getContentType());
+        } catch (MimeTypeException exception) {
+            // Do nothing
+        }
+
+        if (isNull(result) || !isAllowedMimeType(result)) {
+            throw new PictureUploadException("Unable to upload the picture because its format is incorrect.");
+        }
+
+        return result;
+    }
+
+    private boolean isAllowedMimeType(MimeType mimeType) {
+        return ALLOWED_MIME_TYPES.contains(mimeType);
+    }
 }

codiki-exposition/src/main/java/org/codiki/exposition/picture/PictureController.java

@@ -3,9 +3,13 @@ package org.codiki.exposition.picture;
 import java.io.File;
 import java.util.UUID;
 
+import static org.springframework.http.MediaType.APPLICATION_OCTET_STREAM_VALUE;
 import static org.springframework.http.MediaType.MULTIPART_FORM_DATA_VALUE;
 import org.codiki.application.picture.PictureUseCases;
 import org.codiki.domain.picture.model.Picture;
+import org.springframework.core.io.FileSystemResource;
+import org.springframework.web.bind.annotation.GetMapping;
+import org.springframework.web.bind.annotation.PathVariable;
 import org.springframework.web.bind.annotation.PostMapping;
 import org.springframework.web.bind.annotation.RequestMapping;
 import org.springframework.web.bind.annotation.RequestParam;
@@ -32,4 +36,10 @@ public class PictureController {
         Picture newPicture = pictureUseCases.createPicture(pictureFile);
         return newPicture.id();
     }
+
+    @GetMapping(value = "/{pictureId}", produces = APPLICATION_OCTET_STREAM_VALUE)
+    public FileSystemResource loadPicture(@PathVariable("pictureId") UUID pictureId) {
+        Picture picture = pictureUseCases.findById(pictureId);
+        return new FileSystemResource(picture.contentFile());
+    }
 }