US10: Make it possible for horse information to be displayed on the view page, add a get image method to the API

backend/src/main/java/at/ac/tuwien/sepm/assignment/individual/endpoint/HorseEndpoint.java

@@ -11,6 +11,7 @@ import org.slf4j.LoggerFactory;
 import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.dao.DataAccessException;
 import org.springframework.http.HttpStatus;
+import org.springframework.http.MediaType;
 import org.springframework.web.bind.annotation.*;
 import org.springframework.web.multipart.MultipartFile;
 import org.springframework.web.server.ResponseStatusException;
@@ -146,4 +147,24 @@ public class HorseEndpoint {
                 "Something went wrong while uploading the file");
         }
     }
+
+    @RequestMapping(value = "/image/{path}", produces = {MediaType.IMAGE_JPEG_VALUE,MediaType.IMAGE_PNG_VALUE}, method=RequestMethod.GET)
+    @ResponseStatus(HttpStatus.OK)
+    public @ResponseBody byte[] getImage(@PathVariable("path") String path) {
+        // Get the image as byte array and return it with a media type assigned
+        // https://www.baeldung.com/spring-controller-return-image-file
+        // https://docs.spring.io/spring-framework/docs/current/javadoc-api/org/springframework/http/MediaType.html
+        LOGGER.info("GET " + BASE_URL + "/image/{}", path);
+        try {
+            return horseService.getImage(path);
+        } catch(ValidationException e) {
+            LOGGER.error(e.getMessage());
+            throw new ResponseStatusException(HttpStatus.BAD_REQUEST,
+                "Unsupported file type provided. Supported file types are jpg and png.");
+        } catch (IOException e) {
+            LOGGER.error(e.getMessage());
+            throw new ResponseStatusException(HttpStatus.NOT_FOUND,
+                "Something went wrong while reading the file");
+        }
+    }
 }

backend/src/main/java/at/ac/tuwien/sepm/assignment/individual/persistence/FileDao.java

@@ -18,4 +18,12 @@ public interface FileDao {
      * @throws IOException if something goes wrong with deleting the file
      */
     void delete(String fileName) throws IOException;
+
+    /**
+     * Used fot getting a file from the local filesystem
+     * @param fileName of the file to open
+     * @return the file as bytes
+     * @throws IOException if something goes wrong during file access
+     */
+    byte[] get(String fileName) throws IOException;
 }

backend/src/main/java/at/ac/tuwien/sepm/assignment/individual/persistence/impl/HorseFileDao.java

@@ -63,4 +63,21 @@ public class HorseFileDao implements FileDao {
             throw new IOException("Deleting the file specified failed");
         }
     }
+
+    @Override
+    public byte[] get(String fileName) throws IOException {
+        if(fileName == null || fileName.equals(""))
+            throw new IOException("Cannot open an unexisting file");
+
+        LOGGER.trace("Getting file from " + FILE_BASE_PATH + fileName);
+        try {
+            // Read the file and return a byte array
+            // https://stackoverflow.com/a/5083666
+            File imageFile = new File(FILE_BASE_PATH + fileName);
+            return Files.readAllBytes(imageFile.toPath());
+        } catch(Exception e) {
+            LOGGER.error(e.getMessage());
+            throw new IOException("Opening the file specified failed");
+        }
+    }
 }

backend/src/main/java/at/ac/tuwien/sepm/assignment/individual/service/HorseService.java

@@ -64,4 +64,12 @@ public interface HorseService {
      * @throws ValidationException will be thrown if the file is in the incorrect format
      */
     void saveImage(MultipartFile img) throws IOException, ValidationException;
+
+    /**
+     * @param path of the image to get
+     * @return the image
+     * @throws IOException         will be thrown if the file could not be accessed
+     * @throws ValidationException will be thrown if the path does not end with .jpg, .jpeg or .png
+     */
+    byte[] getImage(String path) throws IOException, ValidationException;
 }

backend/src/main/java/at/ac/tuwien/sepm/assignment/individual/service/impl/SimpleHorseService.java

@@ -78,4 +78,11 @@ public class SimpleHorseService implements HorseService {
         LOGGER.trace("saveImage({})", img.getName());
         horseFileDao.save(img);
     }
+
+    @Override
+    public byte[] getImage(String path) throws IOException, ValidationException {
+        this.validator.validateImageRequest(path);
+        LOGGER.trace("getImage({})", path);
+        return horseFileDao.get(path);
+    }
 }

backend/src/main/java/at/ac/tuwien/sepm/assignment/individual/util/Validator.java

@@ -68,6 +68,15 @@ public class Validator {
         }
     }
 
+    public void validateImageRequest(String path) throws ValidationException {
+        if(path == null || path.isEmpty()) {
+            throw new ValidationException("No image path supplied");
+        }
+        if(!path.endsWith(".png") && !path.endsWith(".jpg") && !path.endsWith(".jpeg")) {
+            throw new ValidationException("Unsupported file extension supplied.");
+        }
+    }
+
     public void validateHorseFilter(Map<String, String> filters) throws ValidationException {
         if(filters.get("score") != null) {
             try {