Worked on #15326. Implemented controller, configurable properties...

Worked on #15326. Implemented controller, configurable properties imgupload.thumbnail.{width, heigth}, stared on working on communication between client and server.

src/main/java/de/thm/arsnova/ImageUtils.java

@@ -33,6 +33,9 @@ import javax.imageio.ImageIO;
 import org.apache.commons.codec.binary.Base64;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
+import org.springframework.beans.factory.annotation.Value;
+
+import de.thm.arsnova.entities.Answer;
 
 /**
  * Util class for image operations.
@@ -51,7 +54,21 @@ public class ImageUtils {
 	 */
 	public static final Pattern BASE64_IMAGE_PREFIX_PATTERN = Pattern.compile("data:image/(.*);base64,(.*)");
 	
-
+	/* default value is 200 pixel in width, set the value in the configuration file */
+	private static int THUMB_WIDTH = 200;
+	/* default value is 200 pixel in height, set the value in the configuration file */
+	private static int THUMB_HEIGHT = 200;
+	
+	@Value(value = "{imageupload.thumbnail.width}")
+	public void setThumbWidth(int thumbWidth) {
+		ImageUtils.THUMB_WIDTH = thumbWidth;
+	}
+	
+	@Value(value = "{imageupload.thumbnail.height}")
+	public void setThumbHeight(int thumbHeight) {
+		ImageUtils.THUMB_HEIGHT = thumbHeight;
+	}
+	
 	private ImageUtils() {
 	}
 
@@ -113,7 +130,7 @@ public class ImageUtils {
 	 *            the new height
 	 * @return The rescaled Image as Base64-encoded {@link String}
 	 */
-	public static String rescaleImage(String originalImageString, final int width, final int height) {
+	public static String createCover(String originalImageString, final int width, final int height) {
 		if (!isBase64EncodedImage(originalImageString)) return null;
 		else {
 			Matcher imageMatcher = BASE64_IMAGE_PREFIX_PATTERN.matcher(originalImageString);
@@ -165,6 +182,13 @@ public class ImageUtils {
 			}
 		}
 	}
+	
+	public static void generateThumbnailImage(Answer answer) {
+		if (!isBase64EncodedImage(answer.getAnswerThumbnailImage())) {
+			final String thumbImage = createCover(answer.getAnswerImage(), THUMB_WIDTH, THUMB_HEIGHT);
+			answer.setAnswerThumbnailImage(thumbImage);
+		}
+	}
 
 	/**
 	 * Gets the bytestream of an image url.

src/main/java/de/thm/arsnova/controller/LecturerQuestionController.java

@@ -37,6 +37,8 @@ import org.springframework.web.bind.annotation.RestController;
 
 import de.thm.arsnova.entities.Answer;
 import de.thm.arsnova.entities.Question;
+import de.thm.arsnova.entities.transport.ThumbnailRequest;
+import de.thm.arsnova.entities.transport.ThumbnailResponse;
 import de.thm.arsnova.exceptions.BadRequestException;
 import de.thm.arsnova.exceptions.ForbiddenException;
 import de.thm.arsnova.exceptions.NoContentException;
@@ -338,6 +340,24 @@ public class LecturerQuestionController extends AbstractController {
 			) {
 		return questionService.updateAnswer(answer);
 	}
+	
+	@RequestMapping(value = "/{questionId}/thumbs", method = RequestMethod.POST)
+	public ThumbnailResponse getThumbnails(
+			@PathVariable final String questionId,
+			@RequestBody final ThumbnailRequest thumbRequest
+			) {
+		
+		return questionService.getThumbnails(questionId, thumbRequest);
+	}
+	
+	@RequestMapping(value = "/{questionId}/answer/{answerId}/image", method = RequestMethod.GET)
+	public String getImage(
+			@PathVariable final String questionId,
+			@PathVariable final String answerId
+			) {
+		
+		return questionService.getImage(questionId, answerId);
+	}
 
 	@RequestMapping(value = "/{questionId}/answer/{answerId}", method = RequestMethod.DELETE)
 	public void deleteAnswer(

src/main/java/de/thm/arsnova/entities/Answer.java

@@ -36,7 +36,9 @@ public class Answer {
 	private int answerCount = 1;
 	private boolean abstention;
 	private int abstentionCount;
+	@JsonIgnore
 	private String answerImage;
+	@JsonIgnore
 	private String answerThumbnailImage;
 
 	public Answer() {
@@ -115,6 +117,7 @@ public class Answer {
 		return user;
 	}
 	
+	@JsonIgnore
 	public String getAnswerImage() {
 		return answerImage;
 	}
@@ -123,6 +126,7 @@ public class Answer {
 		this.answerImage = answerImage;
 	}
 	
+	@JsonIgnore
 	public String getAnswerThumbnailImage() {
 		return answerThumbnailImage;
 	}

src/main/java/de/thm/arsnova/entities/transport/ThumbnailRequest.java

+package de.thm.arsnova.entities.transport;
+
+import java.util.List;
+
+import com.fasterxml.jackson.annotation.JsonInclude;
+
+@JsonInclude(JsonInclude.Include.NON_DEFAULT)
+public class ThumbnailRequest {
+
+	private String questionId;
+	private List<String> answerIds;
+	
+	public String getQuestionId() {
+		return questionId;
+	}
+	
+	public List<String> getAnswerIds() {
+		return answerIds;
+	}
+	
+	public void setQuestionId(String questionId) {
+		this.questionId = questionId;
+	}
+	
+	public void setAnswerIds(List<String> answerIds) {
+		this.answerIds = answerIds;
+	}
+	
+}

src/main/java/de/thm/arsnova/entities/transport/ThumbnailResponse.java

+package de.thm.arsnova.entities.transport;
+
+import java.util.ArrayList;
+import java.util.List;
+
+import com.fasterxml.jackson.annotation.JsonIgnore;
+import com.fasterxml.jackson.annotation.JsonInclude;
+
+@JsonInclude(JsonInclude.Include.NON_DEFAULT)
+public class ThumbnailResponse {
+
+	private String questionId;
+	private List<ThumbnailResponseEntry> entries;
+	
+	public String getQuestionId() {
+		return questionId;
+	}
+	
+	public void setQuestionId(String questionId) {
+		this.questionId = questionId;
+	}
+	
+	public List<ThumbnailResponseEntry> getEntries() {
+		return entries;
+	}
+	
+	@JsonIgnore
+	public void addThumbnailEntry(String answerId, String answerThumbnailImage) {
+		if (entries == null) {
+			entries = new ArrayList<>();
+		}
+		entries.add(new ThumbnailResponseEntry(answerId, answerThumbnailImage));
+	}
+
+	@JsonInclude(JsonInclude.Include.NON_DEFAULT)
+	static class ThumbnailResponseEntry {
+		
+		private String answerId;
+		private String answerThumbnailImage;
+		
+		public ThumbnailResponseEntry(String answerId, String answerThumbnailImage) {
+			this.answerId = answerId;
+			this.answerThumbnailImage = answerThumbnailImage;
+		}
+		
+		public String getAnswerId() {
+			return answerId;
+		}
+		
+		public String getAnswerThumbnailImage() {
+			return answerThumbnailImage;
+		}
+		
+		public void setAnswerId(String answerId) {
+			this.answerId = answerId;
+		}
+		
+		public void setAnswerThumbnailImage(String answerThumbnailImage) {
+			this.answerThumbnailImage = answerThumbnailImage;
+		}
+		
+	}
+}

src/main/java/de/thm/arsnova/services/IQuestionService.java

@@ -25,6 +25,8 @@ import de.thm.arsnova.entities.InterposedQuestion;
 import de.thm.arsnova.entities.InterposedReadingCount;
 import de.thm.arsnova.entities.Question;
 import de.thm.arsnova.entities.User;
+import de.thm.arsnova.entities.transport.ThumbnailRequest;
+import de.thm.arsnova.entities.transport.ThumbnailResponse;
 
 public interface IQuestionService {
 	Question saveQuestion(Question question);
@@ -136,4 +138,8 @@ public interface IQuestionService {
 	void deleteAllLectureAnswers(String sessionkey);
 
 	int getAbstentionAnswerCount(String questionId);
+
+	ThumbnailResponse getThumbnails(String questionId, ThumbnailRequest thumbRequest);
+
+	String getImage(String questionId, String answerId);
 }

src/main/java/de/thm/arsnova/services/QuestionService.java

@@ -25,6 +25,7 @@ import java.util.Date;
 import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
+
 import java.util.Timer;
 import java.util.TimerTask;
 
@@ -45,6 +46,8 @@ import de.thm.arsnova.entities.InterposedReadingCount;
 import de.thm.arsnova.entities.Question;
 import de.thm.arsnova.entities.Session;
 import de.thm.arsnova.entities.User;
+import de.thm.arsnova.entities.transport.ThumbnailRequest;
+import de.thm.arsnova.entities.transport.ThumbnailResponse;
 import de.thm.arsnova.events.DeleteAllLectureAnswersEvent;
 import de.thm.arsnova.events.DeleteAllPreparationAnswersEvent;
 import de.thm.arsnova.events.DeleteAllQuestionsAnswersEvent;
@@ -782,4 +785,42 @@ public class QuestionService implements IQuestionService, ApplicationEventPublis
 	public void setApplicationEventPublisher(ApplicationEventPublisher publisher) {
 		this.publisher = publisher;
 	}
+
+	@Override
+	public ThumbnailResponse getThumbnails(String questionId, ThumbnailRequest thumbRequest) {
+		final ThumbnailResponse response = new ThumbnailResponse();
+
+		response.setQuestionId(thumbRequest.getQuestionId());
+		final List<Answer> answers = getAnswers(questionId);
+
+		outer: for (String answerId : thumbRequest.getAnswerIds()) {
+			for (Answer answer : answers) {
+				if (answerId != null && answerId.equals(answer.get_id())) {
+					response.addThumbnailEntry(answerId, answer.getAnswerThumbnailImage());
+					break outer;
+				}
+			}
+		}
+
+		return response;
+	}
+
+	@Override
+	public String getImage(String questionId, String answerId) {
+		final List<Answer> answers = getAnswers(questionId);
+		Answer answer = null;
+
+		for (Answer a : answers) {
+			if (answerId.equals(a.get_id())) {
+				answer = a;
+				break;
+			}
+		}
+
+		if (answer == null) {
+			throw new NotFoundException();
+		}
+
+		return answer.getAnswerImage();
+	}
 }