Erweiterungen

src/main/java/de/assecutor/votianlt/controller/MessageApiController.java

@@ -1,6 +1,7 @@
 package de.assecutor.votianlt.controller;
 
 import de.assecutor.votianlt.model.Message;
+import de.assecutor.votianlt.model.MessageContentType;
 import de.assecutor.votianlt.model.MessageOrigin;
 import de.assecutor.votianlt.service.MessageService;
 import lombok.extern.slf4j.Slf4j;
@@ -30,7 +31,7 @@ public class MessageApiController {
     /**
      * Send a general message to a client
      * POST /api/messages/send
-     * Body: { "content": "message text", "sender": "username", "receiver": "username" }
+     * Body: { "content": "message text", "sender": "username", "receiver": "username", "contentType": "TEXT|IMAGE" }
      */
     @PostMapping("/send")
     public ResponseEntity<Message> sendGeneralMessage(@RequestBody Map<String, String> request) {
@@ -38,6 +39,7 @@ public class MessageApiController {
             String content = request.get("content");
             String sender = request.get("sender");
             String receiver = request.get("receiver");
+            MessageContentType contentType = resolveContentType(request.get("contentType"));
 
             if (content == null || content.isBlank() || 
                 sender == null || sender.isBlank() || 
@@ -46,10 +48,13 @@ public class MessageApiController {
                 return ResponseEntity.badRequest().build();
             }
 
-            Message message = messageService.sendGeneralMessageToClient(content, sender, receiver);
+            Message message = messageService.sendGeneralMessageToClient(content, sender, receiver, contentType);
             log.info("General message sent from {} to {}", sender, receiver);
             return ResponseEntity.ok(message);
 
+        } catch (IllegalArgumentException e) {
+            log.warn("Invalid general message request: {}", e.getMessage());
+            return ResponseEntity.badRequest().build();
         } catch (Exception e) {
             log.error("Error sending general message: {}", e.getMessage(), e);
             return ResponseEntity.status(HttpStatus.INTERNAL_SERVER_ERROR).build();
@@ -60,7 +65,7 @@ public class MessageApiController {
      * Send a job-related message to a client
      * POST /api/messages/send-job-message
      * Body: { "content": "message text", "sender": "username", "receiver": "username", 
-     *         "jobId": "job id", "jobNumber": "job number" }
+     *         "jobId": "job id", "jobNumber": "job number", "contentType": "TEXT|IMAGE" }
      */
     @PostMapping("/send-job-message")
     public ResponseEntity<Message> sendJobMessage(@RequestBody Map<String, String> request) {
@@ -70,6 +75,7 @@ public class MessageApiController {
             String receiver = request.get("receiver");
             String jobIdStr = request.get("jobId");
             String jobNumber = request.get("jobNumber");
+            MessageContentType contentType = resolveContentType(request.get("contentType"));
 
             if (content == null || content.isBlank() || 
                 sender == null || sender.isBlank() || 
@@ -80,12 +86,12 @@ public class MessageApiController {
             }
 
             ObjectId jobId = new ObjectId(jobIdStr);
-            Message message = messageService.sendJobMessageToClient(content, sender, receiver, jobId, jobNumber);
+            Message message = messageService.sendJobMessageToClient(content, sender, receiver, contentType, jobId, jobNumber);
             log.info("Job-related message sent from {} to {} for job {}", sender, receiver, jobNumber);
             return ResponseEntity.ok(message);
 
         } catch (IllegalArgumentException e) {
-            log.error("Invalid jobId format: {}", e.getMessage());
+            log.warn("Invalid job message request: {}", e.getMessage());
             return ResponseEntity.badRequest().build();
         } catch (Exception e) {
             log.error("Error sending job message: {}", e.getMessage(), e);
@@ -228,4 +234,16 @@ public class MessageApiController {
             return ResponseEntity.status(HttpStatus.INTERNAL_SERVER_ERROR).build();
         }
     }
+
+    private MessageContentType resolveContentType(String rawValue) {
+        if (rawValue == null || rawValue.isBlank()) {
+            return MessageContentType.TEXT;
+        }
+
+        try {
+            return MessageContentType.valueOf(rawValue.trim().toUpperCase());
+        } catch (IllegalArgumentException ex) {
+            throw new IllegalArgumentException("Unsupported contentType: " + rawValue, ex);
+        }
+    }
 }

src/main/java/de/assecutor/votianlt/controller/MessageController.java

@@ -601,7 +601,8 @@ public class MessageController {
      * {
      *   "sender": "appUserUsername",
      *   "receiver": "systemUserUsername",
-     *   "content": "message text",
+     *   "content": "message payload",
+     *   "contentType": "TEXT|IMAGE",
      *   "jobId": "optional job id",
      *   "jobNumber": "optional job number"
      * }

src/main/java/de/assecutor/votianlt/dto/ChatMessageInboundPayload.java

@@ -1,13 +1,18 @@
 package de.assecutor.votianlt.dto;
 
+import de.assecutor.votianlt.model.MessageContentType;
 import java.util.Map;
-
 import org.bson.types.ObjectId;
 
 /**
  * Normalized payload for chat messages sent by mobile clients via MQTT.
  */
-public record ChatMessageInboundPayload(String sender, String receiver, String content, ObjectId jobId, String jobNumber) {
+public record ChatMessageInboundPayload(String sender, String receiver, String content,
+        MessageContentType contentType, ObjectId jobId, String jobNumber) {
+
+    public ChatMessageInboundPayload {
+        contentType = contentType != null ? contentType : MessageContentType.TEXT;
+    }
 
     public static ChatMessageInboundPayload fromPayload(Map<String, Object> payload) {
         if (payload == null) {
@@ -17,10 +22,11 @@ public record ChatMessageInboundPayload(String sender, String receiver, String c
         String sender = extractRequiredString(payload, "sender");
         String receiver = extractRequiredString(payload, "receiver");
         String content = extractRequiredString(payload, "content");
+        MessageContentType contentType = extractContentType(payload.get("contentType"));
         ObjectId jobId = extractObjectId(payload.get("jobId"), "jobId");
         String jobNumber = extractOptionalString(payload.get("jobNumber"));
 
-        return new ChatMessageInboundPayload(sender, receiver, content, jobId, jobNumber);
+        return new ChatMessageInboundPayload(sender, receiver, content, contentType, jobId, jobNumber);
     }
 
     public boolean hasJobContext() {
@@ -56,4 +62,16 @@ public record ChatMessageInboundPayload(String sender, String receiver, String c
                     "Field '%s' must be a valid MongoDB ObjectId".formatted(fieldName), ex);
         }
     }
+
+    private static MessageContentType extractContentType(Object value) {
+        String candidate = extractOptionalString(value);
+        if (candidate == null) {
+            return MessageContentType.TEXT;
+        }
+        try {
+            return MessageContentType.valueOf(candidate.trim().toUpperCase());
+        } catch (IllegalArgumentException ex) {
+            throw new IllegalArgumentException("Unsupported contentType '%s'".formatted(candidate), ex);
+        }
+    }
 }

src/main/java/de/assecutor/votianlt/dto/ChatMessageOutboundPayload.java

@@ -1,6 +1,7 @@
 package de.assecutor.votianlt.dto;
 
 import de.assecutor.votianlt.model.Message;
+import de.assecutor.votianlt.model.MessageContentType;
 import de.assecutor.votianlt.model.MessageOrigin;
 import de.assecutor.votianlt.model.MessageType;
 import java.time.LocalDateTime;
@@ -13,6 +14,7 @@ public record ChatMessageOutboundPayload(
         String sender,
         String receiver,
         String content,
+        MessageContentType contentType,
         MessageOrigin origin,
         MessageType messageType,
         LocalDateTime createdAt,
@@ -27,6 +29,7 @@ public record ChatMessageOutboundPayload(
                 message.getSender(),
                 message.getReceiver(),
                 message.getContent(),
+                message.getContentType(),
                 message.getOrigin(),
                 message.getMessageType(),
                 message.getCreatedAt(),

src/main/java/de/assecutor/votianlt/model/Message.java

@@ -25,11 +25,17 @@ public class Message {
     private ObjectId id;
 
     /**
-     * Content of the message
+     * Content of the message, either plain text or base64 encoded media
      */
     @Field("content")
     private String content;
 
+    /**
+     * Declares how to interpret the content payload
+     */
+    @Field("content_type")
+    private MessageContentType contentType = MessageContentType.TEXT;
+
     /**
      * Username of the sender (app user or system user)
      */
@@ -88,29 +94,35 @@ public class Message {
      * Constructor for general messages
      */
     public Message(String content, String sender, String receiver, MessageOrigin origin) {
-        this.content = content;
+        this(content, sender, receiver, origin, MessageContentType.TEXT);
-        this.sender = sender;
+    }
-        this.receiver = receiver;
+
-        this.origin = origin;
+    /**
+     * Constructor for general messages with explicit content type
+     */
+    public Message(String content, String sender, String receiver, MessageOrigin origin,
+            MessageContentType contentType) {
+        initializeBaseFields(content, sender, receiver, origin, contentType);
         this.messageType = MessageType.GENERAL;
-        this.createdAt = LocalDateTime.now();
-        this.isRead = false;
     }
 
     /**
      * Constructor for job-related messages
      */
     public Message(String content, String sender, String receiver, MessageOrigin origin,
-                   ObjectId jobId, String jobNumber) {
+            ObjectId jobId, String jobNumber) {
-        this.content = content;
+        this(content, sender, receiver, origin, MessageContentType.TEXT, jobId, jobNumber);
-        this.sender = sender;
+    }
-        this.receiver = receiver;
+
-        this.origin = origin;
+    /**
+     * Constructor for job-related messages with explicit content type
+     */
+    public Message(String content, String sender, String receiver, MessageOrigin origin,
+            MessageContentType contentType, ObjectId jobId, String jobNumber) {
+        initializeBaseFields(content, sender, receiver, origin, contentType);
         this.messageType = MessageType.JOB_RELATED;
         this.jobId = jobId;
         this.jobNumber = jobNumber;
-        this.createdAt = LocalDateTime.now();
-        this.isRead = false;
     }
 
     /**
@@ -136,4 +148,22 @@ public class Message {
     public String getJobIdAsString() {
         return jobId != null ? jobId.toString() : null;
     }
+
+    /**
+     * Ensure callers always receive a non-null content type to simplify rendering
+     */
+    public MessageContentType getContentType() {
+        return contentType != null ? contentType : MessageContentType.TEXT;
+    }
+
+    private void initializeBaseFields(String content, String sender, String receiver, MessageOrigin origin,
+            MessageContentType contentType) {
+        this.content = content;
+        this.sender = sender;
+        this.receiver = receiver;
+        this.origin = origin;
+        this.createdAt = LocalDateTime.now();
+        this.isRead = false;
+        this.contentType = contentType != null ? contentType : MessageContentType.TEXT;
+    }
 }

src/main/java/de/assecutor/votianlt/model/MessageContentType.java

@@ -0,0 +1,9 @@
+package de.assecutor.votianlt.model;
+
+/**
+ * Supported content variants for chat messages.
+ */
+public enum MessageContentType {
+    TEXT,
+    IMAGE
+}

src/main/java/de/assecutor/votianlt/pages/view/MessageDetailsView.java

@@ -1,20 +1,27 @@
 package de.assecutor.votianlt.pages.view;
 
 import com.vaadin.flow.component.AttachEvent;
+import com.vaadin.flow.component.Component;
 import com.vaadin.flow.component.DetachEvent;
 import com.vaadin.flow.component.UI;
 import com.vaadin.flow.component.button.Button;
+import com.vaadin.flow.component.dialog.Dialog;
 import com.vaadin.flow.component.html.Div;
 import com.vaadin.flow.component.html.H2;
+import com.vaadin.flow.component.html.Image;
 import com.vaadin.flow.component.html.Main;
 import com.vaadin.flow.component.html.Span;
 import com.vaadin.flow.component.icon.VaadinIcon;
+import com.vaadin.flow.component.notification.Notification;
+import com.vaadin.flow.component.notification.NotificationVariant;
+import com.vaadin.flow.component.orderedlayout.FlexComponent;
 import com.vaadin.flow.component.orderedlayout.HorizontalLayout;
 import com.vaadin.flow.component.orderedlayout.Scroller;
 import com.vaadin.flow.component.orderedlayout.VerticalLayout;
-import com.vaadin.flow.component.notification.Notification;
-import com.vaadin.flow.component.notification.NotificationVariant;
 import com.vaadin.flow.component.textfield.TextArea;
+import com.vaadin.flow.component.upload.Upload;
+import com.vaadin.flow.component.upload.UploadI18N;
+import com.vaadin.flow.component.upload.receivers.MemoryBuffer;
 import com.vaadin.flow.router.BeforeEnterEvent;
 import com.vaadin.flow.router.BeforeEnterObserver;
 import com.vaadin.flow.router.PageTitle;
@@ -23,6 +30,7 @@ import com.vaadin.flow.router.RouteParameters;
 import com.vaadin.flow.shared.Registration;
 import de.assecutor.votianlt.model.AppUser;
 import de.assecutor.votianlt.model.Message;
+import de.assecutor.votianlt.model.MessageContentType;
 import de.assecutor.votianlt.model.MessageOrigin;
 import de.assecutor.votianlt.model.MessageType;
 import de.assecutor.votianlt.pages.service.AppUserService;
@@ -33,13 +41,17 @@ import jakarta.annotation.security.RolesAllowed;
 import lombok.extern.slf4j.Slf4j;
 import org.bson.types.ObjectId;
 
+import java.io.IOException;
+import java.io.InputStream;
 import java.time.LocalDate;
 import java.time.LocalDateTime;
 import java.time.format.DateTimeFormatter;
+import java.util.Base64;
 import java.util.List;
-import java.util.Optional;
-import java.util.stream.Collectors;
 import java.util.Objects;
+import java.util.Optional;
+import java.util.concurrent.atomic.AtomicReference;
+import java.util.stream.Collectors;
 
 @Route(value = "message-details/:clientId/:conversationId", layout = de.assecutor.votianlt.pages.base.ui.view.MainLayout.class)
 @PageTitle("Nachrichtenverlauf")
@@ -63,8 +75,10 @@ public class MessageDetailsView extends Main implements BeforeEnterObserver {
     private Div scrollAnchor; // Anchor element for scrolling to bottom
     private List<Message> currentMessages; // Current messages being displayed for redrawing
     private Registration broadcasterRegistration; // Track listener registration
+    private TextArea messageInput;
     private static final DateTimeFormatter TIME_FORMATTER = DateTimeFormatter.ofPattern("HH:mm");
     private static final DateTimeFormatter DATE_FORMATTER = DateTimeFormatter.ofPattern("dd.MM.yyyy");
+    private static final int MAX_IMAGE_FILE_SIZE = 32 * 1024 * 1024; // 32 MB aligns with Spring settings
 
     public MessageDetailsView(AppUserService appUserService, MessageService messageService,
             SecurityService securityService, MessageBroadcaster messageBroadcaster) {
@@ -196,6 +210,141 @@ public class MessageDetailsView extends Main implements BeforeEnterObserver {
         }
     }
 
+    private void openImageUploadDialog() {
+        Dialog dialog = new Dialog();
+        dialog.setHeaderTitle("Bild anhängen");
+        dialog.setCloseOnEsc(true);
+        dialog.setCloseOnOutsideClick(true);
+        dialog.setWidth("480px");
+
+        MemoryBuffer buffer = new MemoryBuffer();
+        Upload upload = new Upload(buffer);
+        upload.setAcceptedFileTypes("image/png", "image/jpeg", "image/gif", "image/webp");
+        upload.setMaxFiles(1);
+        upload.setMaxFileSize(MAX_IMAGE_FILE_SIZE);
+        upload.setI18n(createGermanUploadI18n());
+        upload.setWidthFull();
+
+        Span helper = new Span("Unterstützte Formate: PNG, JPG, GIF, WebP (max. 32 MB)");
+        helper.getStyle()
+            .set("font-size", "12px")
+            .set("color", "#666666");
+
+        Image preview = new Image();
+        preview.setAlt("Vorschau des ausgewählten Bildes");
+        preview.setVisible(false);
+        preview.setWidth(null);
+        preview.setHeight(null);
+        preview.getStyle()
+            .set("max-width", "100%")
+            .set("max-height", "320px")
+            .set("height", "auto")
+            .set("border-radius", "12px")
+            .set("display", "inline-block");
+
+        Div previewWrapper = new Div(preview);
+        previewWrapper.setWidthFull();
+        previewWrapper.getStyle()
+            .set("text-align", "center")
+            .set("margin-top", "10px");
+
+        AtomicReference<String> base64Ref = new AtomicReference<>();
+
+        Button confirmButton = new Button("Senden");
+        confirmButton.addThemeVariants(com.vaadin.flow.component.button.ButtonVariant.LUMO_PRIMARY);
+        confirmButton.setEnabled(false);
+
+        Button cancelButton = new Button("Abbrechen", event -> dialog.close());
+
+        upload.addSucceededListener(event -> {
+            try (InputStream inputStream = buffer.getInputStream()) {
+                byte[] bytes = inputStream.readAllBytes();
+                if (bytes.length == 0) {
+                    base64Ref.set(null);
+                    preview.setVisible(false);
+                    confirmButton.setEnabled(false);
+                    Notification.show("Die Bilddatei ist leer.", 3000, Notification.Position.MIDDLE)
+                            .addThemeVariants(NotificationVariant.LUMO_ERROR);
+                    return;
+                }
+
+                String base64 = Base64.getEncoder().encodeToString(bytes);
+                base64Ref.set(base64);
+
+                String mimeType = Optional.ofNullable(event.getMIMEType()).filter(value -> !value.isBlank())
+                        .orElseGet(() -> detectImageMimeType(bytes));
+                String dataUrl = createDataUrlFromContent(base64, mimeType);
+                if (dataUrl == null) {
+                    preview.setVisible(false);
+                    confirmButton.setEnabled(false);
+                    Notification.show("Das Bild konnte nicht verarbeitet werden.", 3000,
+                            Notification.Position.MIDDLE).addThemeVariants(NotificationVariant.LUMO_ERROR);
+                    return;
+                }
+
+                preview.setSrc(dataUrl);
+                preview.setVisible(true);
+                confirmButton.setEnabled(true);
+            } catch (IOException ex) {
+                log.error("Fehler beim Verarbeiten der Bilddatei", ex);
+                base64Ref.set(null);
+                preview.setVisible(false);
+                confirmButton.setEnabled(false);
+                Notification.show("Das Bild konnte nicht gelesen werden.", 3000, Notification.Position.MIDDLE)
+                        .addThemeVariants(NotificationVariant.LUMO_ERROR);
+            }
+        });
+
+        upload.addFileRejectedListener(event -> {
+            base64Ref.set(null);
+            preview.setVisible(false);
+            confirmButton.setEnabled(false);
+            Notification.show(event.getErrorMessage(), 3000, Notification.Position.MIDDLE)
+                    .addThemeVariants(NotificationVariant.LUMO_ERROR);
+        });
+
+        upload.addFailedListener(event -> {
+            base64Ref.set(null);
+            preview.setVisible(false);
+            confirmButton.setEnabled(false);
+            Notification.show("Der Upload ist fehlgeschlagen.", 3000, Notification.Position.MIDDLE)
+                    .addThemeVariants(NotificationVariant.LUMO_ERROR);
+        });
+
+        upload.addFileRemovedListener(event -> {
+            base64Ref.set(null);
+            preview.setVisible(false);
+            confirmButton.setEnabled(false);
+        });
+
+        confirmButton.addClickListener(event -> {
+            String base64 = base64Ref.get();
+            if (base64 == null || base64.isBlank()) {
+                Notification.show("Bitte zuerst ein Bild auswählen.", 2500, Notification.Position.MIDDLE)
+                        .addThemeVariants(NotificationVariant.LUMO_ERROR);
+                return;
+            }
+            dialog.close();
+            sendMessageToParticipant(base64, MessageContentType.IMAGE);
+        });
+
+        VerticalLayout dialogContent = new VerticalLayout(upload, helper, previewWrapper);
+        dialogContent.setSpacing(true);
+        dialogContent.setPadding(false);
+        dialogContent.setAlignItems(FlexComponent.Alignment.STRETCH);
+        dialogContent.setWidthFull();
+
+        HorizontalLayout buttonBar = new HorizontalLayout(cancelButton, confirmButton);
+        buttonBar.setWidthFull();
+        buttonBar.setSpacing(true);
+        buttonBar.setJustifyContentMode(FlexComponent.JustifyContentMode.END);
+
+        dialog.add(dialogContent);
+        dialog.getFooter().add(buttonBar);
+
+        dialog.open();
+    }
+
     /**
      * Create a date separator component
      */
@@ -252,15 +401,8 @@ public class MessageDetailsView extends Main implements BeforeEnterObserver {
             .set("white-space", "pre-wrap")
             .set("text-align", alignment);
         
-        // Message content
+        // Message content component (text or media)
-        Div contentDiv = new Div();
+        Component contentComponent = createContentComponent(message, alignment);
-        String content = Optional.ofNullable(message.getContent()).orElse("(kein Inhalt)");
-        contentDiv.setText(content);
-        contentDiv.getStyle()
-            .set("font-size", "14px")
-            .set("color", "#000000")
-            .set("margin-bottom", "5px")
-            .set("text-align", alignment);
         
         // Timestamp
         Span timeSpan = new Span(timestamp.format(TIME_FORMATTER));
@@ -270,12 +412,147 @@ public class MessageDetailsView extends Main implements BeforeEnterObserver {
             .set("display", "block")
             .set("text-align", alignment);
         
-        bubble.add(contentDiv, timeSpan);
+        bubble.add(contentComponent, timeSpan);
         messageWrapper.add(bubble);
         
         return messageWrapper;
     }
 
+    private Component createContentComponent(Message message, String alignment) {
+        MessageContentType contentType = message.getContentType();
+        return switch (contentType) {
+            case IMAGE -> createImageContent(message.getContent(), alignment);
+            case TEXT -> createTextContent(message.getContent(), alignment);
+        };
+    }
+
+    private Component createTextContent(String contentValue, String alignment) {
+        Div contentDiv = new Div();
+        String content = Optional.ofNullable(contentValue).filter(value -> !value.isBlank())
+                .orElse("(kein Inhalt)");
+        contentDiv.setText(content);
+        contentDiv.getStyle()
+            .set("font-size", "14px")
+            .set("color", "#000000")
+            .set("margin-bottom", "5px")
+            .set("text-align", alignment);
+        return contentDiv;
+    }
+
+    private Component createImageContent(String base64Value, String alignment) {
+        Div wrapper = new Div();
+        wrapper.getStyle()
+            .set("margin-bottom", "5px")
+            .set("display", "flex")
+            .set("justify-content", "right".equals(alignment) ? "flex-end" : "flex-start");
+
+        String trimmed = Optional.ofNullable(base64Value).map(String::trim).orElse("");
+        if (trimmed.isEmpty()) {
+            wrapper.setText("(kein Bildinhalt)");
+            return wrapper;
+        }
+
+        String dataUrl = createDataUrlFromContent(trimmed, null);
+        if (dataUrl == null) {
+            wrapper.setText("(Bild konnte nicht geladen werden)");
+            return wrapper;
+        }
+
+        Image image = new Image(dataUrl, "Nachrichtenbild");
+        image.getStyle()
+            .set("max-width", "100%")
+            .set("border-radius", "12px")
+            .set("display", "block")
+            .set("max-height", "320px")
+            .set("height", "auto");
+        image.getElement().setAttribute("loading", "lazy");
+
+        wrapper.add(image);
+        return wrapper;
+    }
+
+    private String createDataUrlFromContent(String contentValue, String mimeTypeHint) {
+        if (contentValue == null || contentValue.isBlank()) {
+            return null;
+        }
+        String trimmed = contentValue.trim();
+        if (trimmed.startsWith("data:")) {
+            return trimmed;
+        }
+
+        byte[] imageBytes;
+        try {
+            imageBytes = Base64.getDecoder().decode(trimmed);
+        } catch (IllegalArgumentException ex) {
+            log.warn("Ungültiger Base64-Inhalt für Bildnachricht", ex);
+            return null;
+        }
+
+        String mimeType = Optional.ofNullable(mimeTypeHint).filter(value -> !value.isBlank())
+                .orElseGet(() -> detectImageMimeType(imageBytes));
+        return "data:" + mimeType + ";base64," + trimmed;
+    }
+
+    private String detectImageMimeType(byte[] bytes) {
+        if (bytes == null || bytes.length < 4) {
+            return "image/png";
+        }
+
+        if ((bytes[0] & 0xFF) == 0xFF && (bytes[1] & 0xFF) == 0xD8) {
+            return "image/jpeg";
+        }
+        if ((bytes[0] & 0xFF) == 0x89 && bytes[1] == 0x50 && bytes[2] == 0x4E && bytes[3] == 0x47) {
+            return "image/png";
+        }
+        if (bytes[0] == 0x47 && bytes[1] == 0x49 && bytes[2] == 0x46 && bytes[3] == 0x38) {
+            return "image/gif";
+        }
+        if (bytes.length >= 12 && bytes[0] == 0x52 && bytes[1] == 0x49 && bytes[2] == 0x46 && bytes[3] == 0x46
+                && bytes[8] == 0x57 && bytes[9] == 0x45 && bytes[10] == 0x42 && bytes[11] == 0x50) {
+            return "image/webp";
+        }
+        if (bytes[0] == 0x42 && bytes[1] == 0x4D) {
+            return "image/bmp";
+        }
+        return "image/png";
+    }
+
+    private UploadI18N createGermanUploadI18n() {
+        UploadI18N i18n = new UploadI18N();
+
+        UploadI18N.AddFiles addFiles = new UploadI18N.AddFiles();
+        addFiles.setOne("Bild auswählen");
+        addFiles.setMany("Bilder auswählen");
+        i18n.setAddFiles(addFiles);
+
+        UploadI18N.DropFiles dropFiles = new UploadI18N.DropFiles();
+        dropFiles.setOne("Bild hierher ziehen");
+        dropFiles.setMany("Bilder hierher ziehen");
+        i18n.setDropFiles(dropFiles);
+
+        UploadI18N.Error error = new UploadI18N.Error();
+        error.setFileIsTooBig("Die Datei ist größer als 32 MB.");
+        error.setTooManyFiles("Es kann nur ein Bild gleichzeitig hochgeladen werden.");
+        i18n.setError(error);
+
+        UploadI18N.Uploading uploading = new UploadI18N.Uploading();
+        uploading.setStatus(new UploadI18N.Uploading.Status()
+                .setConnecting("Verbindung wird aufgebaut...")
+                .setStalled("Upload pausiert")
+                .setProcessing("Verarbeitung...")
+                .setHeld("Warten auf Upload..."));
+        uploading.setRemainingTime(new UploadI18N.Uploading.RemainingTime()
+                .setPrefix("Verbleibende Zeit: ")
+                .setUnknown("Verbleibende Zeit unbekannt"));
+        uploading.setError(new UploadI18N.Uploading.Error()
+                .setServerUnavailable("Server nicht erreichbar")
+                .setUnexpectedServerError("Unerwarteter Serverfehler")
+                .setForbidden("Upload nicht erlaubt"));
+        i18n.setUploading(uploading);
+
+        return i18n;
+    }
+
     /**
      * Ensure scroll anchor exists at the bottom of messages container
      */
@@ -326,12 +603,20 @@ public class MessageDetailsView extends Main implements BeforeEnterObserver {
 
 
     private HorizontalLayout createMessageInputArea() {
-        TextArea messageInput = new TextArea();
+        messageInput = new TextArea();
         messageInput.setPlaceholder("Nachricht eingeben...");
         messageInput.setWidthFull();
         messageInput.getStyle().set("min-height", "60px");
         messageInput.getStyle().set("max-height", "120px");
 
+        Button attachButton = new Button(VaadinIcon.PAPERCLIP.create());
+        attachButton.addThemeVariants(com.vaadin.flow.component.button.ButtonVariant.LUMO_TERTIARY,
+                com.vaadin.flow.component.button.ButtonVariant.LUMO_ICON);
+        attachButton.getStyle().set("height", "60px");
+        attachButton.getElement().setProperty("title", "Bild anhängen");
+        attachButton.getElement().setAttribute("aria-label", "Bild anhängen");
+        attachButton.addClickListener(event -> openImageUploadDialog());
+
         Button sendButton = new Button("Senden", VaadinIcon.PAPERPLANE.create());
         sendButton.addThemeVariants(com.vaadin.flow.component.button.ButtonVariant.LUMO_PRIMARY);
         sendButton.getStyle().set("height", "60px");
@@ -339,30 +624,43 @@ public class MessageDetailsView extends Main implements BeforeEnterObserver {
         sendButton.addClickListener(e -> {
             String message = messageInput.getValue();
             if (message != null && !message.trim().isEmpty()) {
-                sendMessageToParticipant(message.trim());
+                sendMessageToParticipant(message, MessageContentType.TEXT);
                 messageInput.clear();
             }
         });
 
-        HorizontalLayout layout = new HorizontalLayout(messageInput, sendButton);
+        HorizontalLayout layout = new HorizontalLayout(attachButton, messageInput, sendButton);
         layout.setWidthFull();
-        layout.setAlignItems(com.vaadin.flow.component.orderedlayout.FlexComponent.Alignment.END);
+        layout.setAlignItems(FlexComponent.Alignment.END);
+        layout.setSpacing(true);
         layout.expand(messageInput);
 
         return layout;
     }
 
-    private void sendMessageToParticipant(String content) {
+    private void sendMessageToParticipant(String content, MessageContentType contentType) {
+        String payload = Optional.ofNullable(content).orElse("");
+        if (contentType == MessageContentType.TEXT) {
+            payload = payload.trim();
+        }
+
+        if (payload.isEmpty()) {
+            Notification.show("Nachricht enthält keinen Inhalt.", 2500, Notification.Position.MIDDLE)
+                    .addThemeVariants(NotificationVariant.LUMO_ERROR);
+            return;
+        }
+
         String sender = Optional.ofNullable(securityService.getCurrentUsername()).filter(name -> !name.isBlank())
                 .orElse("System");
 
         try {
             Message saved;
             if (jobConversation) {
-                saved = messageService.sendJobMessageToClient(content, sender, participantKey, jobIdContext,
+                saved = messageService.sendJobMessageToClient(payload, sender, participantKey,
-                        jobNumberContext);
+                        contentType, jobIdContext, jobNumberContext);
             } else {
-                saved = messageService.sendGeneralMessageToClient(content, sender, participantKey);
+                saved = messageService.sendGeneralMessageToClient(payload, sender, participantKey,
+                        contentType);
             }
 
             Notification.show("Nachricht gesendet", 2000, Notification.Position.BOTTOM_END)

src/main/java/de/assecutor/votianlt/pages/view/MessagesView.java

@@ -18,6 +18,7 @@ import com.vaadin.flow.router.Route;
 import de.assecutor.votianlt.dto.ClientMessageSummary;
 import de.assecutor.votianlt.model.AppUser;
 import de.assecutor.votianlt.model.Message;
+import de.assecutor.votianlt.model.MessageContentType;
 import de.assecutor.votianlt.model.MessageOrigin;
 import de.assecutor.votianlt.pages.service.AppUserService;
 import de.assecutor.votianlt.service.MessageService;
@@ -207,7 +208,7 @@ public class MessagesView extends Main {
                     .orElse(conversation.get(0));
 
             LocalDateTime lastDate = latest.getCreatedAt();
-            String preview = Optional.ofNullable(latest.getContent()).filter(s -> !s.isBlank()).orElse("(kein Inhalt)");
+            String preview = resolvePreview(latest);
             int totalMessages = conversation.size();
             int unreadCount = (int) conversation.stream()
                     .filter(msg -> msg.getOrigin() == MessageOrigin.CLIENT && !msg.isRead())
@@ -239,6 +240,20 @@ public class MessagesView extends Main {
         return summaries;
     }
 
+    private String resolvePreview(Message message) {
+        if (message == null) {
+            return "(kein Inhalt)";
+        }
+
+        if (message.getContentType() == MessageContentType.IMAGE) {
+            return "[Bildnachricht]";
+        }
+
+        return Optional.ofNullable(message.getContent())
+                .filter(content -> !content.isBlank())
+                .orElse("(kein Inhalt)");
+    }
+
     private String resolveParticipantKey(Message message) {
         if (message == null) {
             return null;

src/main/java/de/assecutor/votianlt/pages/view/UserMessagesView.java

@@ -16,6 +16,7 @@ import com.vaadin.flow.router.PageTitle;
 import com.vaadin.flow.router.Route;
 import de.assecutor.votianlt.model.AppUser;
 import de.assecutor.votianlt.model.Message;
+import de.assecutor.votianlt.model.MessageContentType;
 import de.assecutor.votianlt.model.MessageOrigin;
 import de.assecutor.votianlt.model.MessageType;
 import de.assecutor.votianlt.pages.service.AppUserService;
@@ -134,7 +135,7 @@ public class UserMessagesView extends Main implements HasUrlParameter<String> {
                 .count();
         int messageCount = sortedMessages.size();
         LocalDateTime lastMessageTime = latest != null ? latest.getCreatedAt() : null;
-        String preview = latest != null ? latest.getContent() : null;
+        String preview = resolvePreview(latest);
 
         section.add(createMessageCard(
                 "Allgemeine Unterhaltung",
@@ -178,7 +179,7 @@ public class UserMessagesView extends Main implements HasUrlParameter<String> {
             String conversationTitle = "Auftrag " + jobKey;
             section.add(createMessageCard(
                     conversationTitle,
-                    Optional.ofNullable(latest.getContent()).orElse(""),
+                    resolvePreview(latest),
                     latest.getCreatedAt(),
                     messages.size(),
                     unreadCount,
@@ -189,6 +190,20 @@ public class UserMessagesView extends Main implements HasUrlParameter<String> {
         return section;
     }
 
+    private String resolvePreview(Message message) {
+        if (message == null) {
+            return "";
+        }
+
+        if (message.getContentType() == MessageContentType.IMAGE) {
+            return "[Bildnachricht]";
+        }
+
+        return Optional.ofNullable(message.getContent())
+                .map(String::trim)
+                .orElse("");
+    }
+
     private Div createMessageCard(String conversationTitle, String lastMessagePreview,
             LocalDateTime lastMessageTime, int messageCount,
             int unreadCount, String conversationId) {

src/main/java/de/assecutor/votianlt/service/MessageService.java

@@ -1,6 +1,7 @@
 package de.assecutor.votianlt.service;
 
 import de.assecutor.votianlt.model.Message;
+import de.assecutor.votianlt.model.MessageContentType;
 import de.assecutor.votianlt.model.MessageOrigin;
 import de.assecutor.votianlt.model.MessageType;
 import de.assecutor.votianlt.dto.ChatMessageInboundPayload;
@@ -44,7 +45,12 @@ public class MessageService {
      * Send a general message to a client via MQTT
      */
     public Message sendGeneralMessageToClient(String content, String sender, String receiver) {
-        Message message = new Message(content, sender, receiver, MessageOrigin.SERVER);
+        return sendGeneralMessageToClient(content, sender, receiver, MessageContentType.TEXT);
+    }
+
+    public Message sendGeneralMessageToClient(String content, String sender, String receiver,
+            MessageContentType contentType) {
+        Message message = new Message(content, sender, receiver, MessageOrigin.SERVER, contentType);
         message = saveMessage(message);
         publishMessageToMqtt(message, receiver);
         return message;
@@ -54,8 +60,13 @@ public class MessageService {
      * Send a job-related message to a client via MQTT
      */
     public Message sendJobMessageToClient(String content, String sender, String receiver,
-                                         ObjectId jobId, String jobNumber) {
+            ObjectId jobId, String jobNumber) {
-        Message message = new Message(content, sender, receiver, MessageOrigin.SERVER, jobId, jobNumber);
+        return sendJobMessageToClient(content, sender, receiver, MessageContentType.TEXT, jobId, jobNumber);
+    }
+
+    public Message sendJobMessageToClient(String content, String sender, String receiver,
+            MessageContentType contentType, ObjectId jobId, String jobNumber) {
+        Message message = new Message(content, sender, receiver, MessageOrigin.SERVER, contentType, jobId, jobNumber);
         message = saveMessage(message);
         publishMessageToMqtt(message, receiver);
         return message;
@@ -66,12 +77,13 @@ public class MessageService {
      */
     public Message receiveMessageFromClient(ChatMessageInboundPayload payload) {
         Message message;
+        MessageContentType contentType = payload.contentType();
         if (payload.hasJobContext()) {
             message = new Message(payload.content(), payload.sender(), payload.receiver(),
-                    MessageOrigin.CLIENT, payload.jobId(), payload.jobNumber());
+                    MessageOrigin.CLIENT, contentType, payload.jobId(), payload.jobNumber());
         } else {
             message = new Message(payload.content(), payload.sender(), payload.receiver(),
-                    MessageOrigin.CLIENT);
+                    MessageOrigin.CLIENT, contentType);
         }
         message = saveMessage(message);