Merge branch 'feature/backend-websockets' into 'main'

Backend websockets

See merge request cse1105/2025-2026/teams/csep-team-76!16

commons/src/main/java/commons/ws/Topics.java

@@ -0,0 +1,5 @@
+package commons.ws;
+
+public class Topics {
+    public static final String RECIPES = "/subscribe/recipe";
+}

commons/src/main/java/commons/ws/messages/CreateRecipeMessage.java

@@ -0,0 +1,30 @@
+package commons.ws.messages;
+
+import commons.Recipe;
+
+/**
+ * Message sent when a new recipe is created.
+ *
+ * @see commons.ws.messages.Message.Type#RECIPE_CREATE
+ */
+public class CreateRecipeMessage implements Message {
+    private Recipe recipe;
+
+    public CreateRecipeMessage(Recipe recipe) {
+        this.recipe = recipe;
+    }
+
+    @Override
+    public Type getType() {
+        return Type.RECIPE_CREATE;
+    }
+
+    /**
+     * Get the created recipe.
+     *
+     * @return The created recipe.
+     */
+    public Recipe getRecipe() {
+        return recipe;
+    }
+}

commons/src/main/java/commons/ws/messages/DeleteRecipeMessage.java

@@ -0,0 +1,28 @@
+package commons.ws.messages;
+
+/**
+ * Message sent when a recipe is deleted.
+ *
+ * @see commons.ws.messages.Message.Type#RECIPE_DELETE
+ */
+public class DeleteRecipeMessage implements Message {
+    private Long recipeId;
+
+    public DeleteRecipeMessage(Long recipeId) {
+        this.recipeId = recipeId;
+    }
+
+    @Override
+    public Type getType() {
+        return Type.RECIPE_DELETE;
+    }
+
+    /**
+     * Get the ID of the deleted recipe.
+     *
+     * @return The ID of the deleted recipe.
+     */
+    public Long getRecipeId() {
+        return recipeId;
+    }
+}

commons/src/main/java/commons/ws/messages/Message.java

@@ -0,0 +1,44 @@
+package commons.ws.messages;
+
+public interface Message {
+    public enum Type {
+        /**
+         * Message sent when a new recipe is created.
+         *
+         * @see commons.ws.messages.CreateRecipeMessage
+         */
+        RECIPE_CREATE,
+
+        /**
+         * Message sent when an existing recipe is updated.
+         *
+         * @see commons.ws.messages.UpdateRecipeMessage
+         */
+        RECIPE_UPDATE,
+
+        /**
+         * Message sent when a recipe is deleted.
+         *
+         * @see commons.ws.messages.DeleteRecipeMessage
+         */
+        RECIPE_DELETE
+    }
+
+    /**
+     * Get the type of the message.
+     * This can be used to match the message to the appropriate handler.
+     *
+     * <h3>Example</h3>
+     * <pre>
+     * Message msg = ...;
+     * switch (msg.getType()) {
+     *     case RECIPE_CREATE -> handleCreate((CreateRecipeMessage) msg);
+     *     case RECIPE_UPDATE -> handleUpdate((UpdateRecipeMessage) msg);
+     *     default -> { /* handle other cases *\/ }
+     * }
+     * </pre>
+     *
+     * @return The type of the message.
+     */
+    public Type getType();
+}

commons/src/main/java/commons/ws/messages/UpdateRecipeMessage.java

@@ -0,0 +1,30 @@
+package commons.ws.messages;
+
+import commons.Recipe;
+
+/**
+ * Message sent when an existing recipe is updated.
+ *
+ * @see commons.ws.messages.Message.Type#RECIPE_UPDATE
+ */
+public class UpdateRecipeMessage implements Message {
+    private Recipe recipe;
+
+    public UpdateRecipeMessage(Recipe recipe) {
+        this.recipe = recipe;
+    }
+
+    @Override
+    public Type getType() {
+        return Type.RECIPE_UPDATE;
+    }
+
+    /**
+     * Get the updated recipe.
+     *
+     * @return The updated recipe.
+     */
+    public Recipe getRecipe() {
+        return recipe;
+    }
+}

server/pom.xml

@@ -26,6 +26,10 @@
             <groupId>org.springframework.boot</groupId>
             <artifactId>spring-boot-starter-data-jpa</artifactId>
         </dependency>
+        <dependency>
+            <groupId>org.springframework.boot</groupId>
+            <artifactId>spring-boot-starter-websocket</artifactId>
+        </dependency>
         <dependency>
             <groupId>com.h2database</groupId>
             <artifactId>h2</artifactId>
@@ -43,6 +47,7 @@
             <artifactId>spring-boot-starter-test</artifactId>
             <scope>test</scope>
         </dependency>
+
     </dependencies>
 
     <build>

server/src/main/java/server/WebSocketConfig.java

@@ -0,0 +1,33 @@
+package server;
+
+import org.springframework.context.annotation.Configuration;
+import org.springframework.messaging.simp.config.MessageBrokerRegistry;
+import org.springframework.web.socket.config.annotation.EnableWebSocketMessageBroker;
+import org.springframework.web.socket.config.annotation.StompEndpointRegistry;
+import org.springframework.web.socket.config.annotation.WebSocketMessageBrokerConfigurer;
+
+@Configuration
+@EnableWebSocketMessageBroker
+public class WebSocketConfig implements WebSocketMessageBrokerConfigurer {
+    @Override
+    public void configureMessageBroker(MessageBrokerRegistry registry) {
+
+        // SUBSCRIBE /subscribe/{mapping}, see UpdateMessagingController definition
+        // adds a broker endpoint subscribers listen to
+        registry.enableSimpleBroker("/subscribe");
+
+        // SEND /send/updates/{mapping}, see UpdateMessagingController definition
+        // the client pushes a new message to this address
+        registry.setApplicationDestinationPrefixes("/send");
+    }
+
+    @Override
+    public void registerStompEndpoints(StompEndpointRegistry registry) {
+        // a client can now push data to /send/updates/{mapping}, see UpdateMessagingController
+        // allow access from any origin: one server, many clients
+        registry.addEndpoint("/updates").setAllowedOrigins("*");
+        // optional, recommended to increase browser & networking support
+        registry.addEndpoint("/updates").setAllowedOrigins("*").withSockJS();
+
+    }
+}

server/src/main/java/server/api/RecipeController.java

@@ -2,10 +2,15 @@ package server.api;
 
 import commons.Recipe;
 
+import commons.ws.Topics;
+import commons.ws.messages.CreateRecipeMessage;
+import commons.ws.messages.DeleteRecipeMessage;
+import commons.ws.messages.UpdateRecipeMessage;
 import org.springframework.data.domain.Example;
 import org.springframework.data.domain.PageRequest;
 import org.springframework.http.ResponseEntity;
 
+import org.springframework.messaging.simp.SimpMessagingTemplate;
 import org.springframework.web.bind.annotation.DeleteMapping;
 import org.springframework.web.bind.annotation.GetMapping;
 import org.springframework.web.bind.annotation.PathVariable;
@@ -25,9 +30,11 @@ import java.util.Optional;
 @RequestMapping("/api")
 public class RecipeController {
     private final RecipeRepository recipeRepository; // JPA repository used in this controller
+    private final SimpMessagingTemplate messagingTemplate;
 
-    public RecipeController(RecipeRepository recipeRepository) {
+    public RecipeController(RecipeRepository recipeRepository, SimpMessagingTemplate messagingTemplate) {
         this.recipeRepository = recipeRepository;
+        this.messagingTemplate = messagingTemplate;
     }
 
     /**
@@ -61,6 +68,7 @@ public class RecipeController {
                             PageRequest.of(0, limit.get())
                     ).toList());
         }
+
         return ResponseEntity.ok(recipeRepository.findAll());
     }
 
@@ -76,9 +84,10 @@ public class RecipeController {
             return ResponseEntity.badRequest().build();
         }
 
-        // TODO: Send WS update to all subscribers with the updated recipe
+        Recipe saved = recipeRepository.save(recipe);
+        messagingTemplate.convertAndSend(Topics.RECIPES, new UpdateRecipeMessage(saved));
 
-        return ResponseEntity.ok(recipeRepository.save(recipe));
+        return ResponseEntity.ok(saved);
     }
 
     /**
@@ -104,9 +113,10 @@ public class RecipeController {
             return ResponseEntity.badRequest().build();
         }
 
-        // TODO: Send WS update to all subscribers with the new recipe
+        Recipe saved = recipeRepository.save(recipe);
+        messagingTemplate.convertAndSend(Topics.RECIPES, new CreateRecipeMessage(saved));
 
-        return ResponseEntity.ok(recipeRepository.save(recipe));
+        return ResponseEntity.ok(saved);
     }
 
     /**
@@ -124,7 +134,8 @@ public class RecipeController {
         }
         recipeRepository.deleteById(id);
 
-        // TODO: Send WS update to propagate deletion
+        messagingTemplate.convertAndSend(Topics.RECIPES, new DeleteRecipeMessage(id));
+
         return ResponseEntity.ok(true);
     }
 }

server/src/main/java/server/api/UpdateMessagingController.java

@@ -0,0 +1,29 @@
+package server.api;
+
+import commons.Recipe;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.http.ResponseEntity;
+import org.springframework.messaging.handler.annotation.MessageMapping;
+import org.springframework.messaging.handler.annotation.SendTo;
+import org.springframework.stereotype.Controller;
+
+@Controller
+public class UpdateMessagingController {
+    private final RecipeController recipeController;
+    @Autowired
+    public UpdateMessagingController(
+            RecipeController recipeController) {
+        this.recipeController = recipeController;
+    }
+
+    /**
+     * Mapping for STOMP: <code>SEND /updates/recipe</code>
+     * @param recipe The request body as a new {@link Recipe} object to update the original into
+     * @return The updated {@link Recipe} object wrapped in a {@link org.springframework.http.ResponseEntity}.
+     */
+    @MessageMapping("/updates/recipe")
+    @SendTo("/subscribe/recipe")
+    public ResponseEntity<Recipe> broadcastRecipeUpdate(Recipe recipe) {
+        return recipeController.updateRecipe(recipe.getId(), recipe);
+    }
+}

server/src/test/java/server/api/RecipeControllerTest.java

@@ -8,8 +8,11 @@ import org.junit.jupiter.api.Test;
 import org.junit.jupiter.api.TestInfo;
 import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.boot.test.autoconfigure.orm.jpa.DataJpaTest;
+import org.springframework.context.annotation.Import;
 import org.springframework.http.HttpStatus;
+import org.springframework.messaging.simp.SimpMessagingTemplate;
 import org.springframework.test.context.ActiveProfiles;
+import server.WebSocketConfig;
 import server.database.RecipeRepository;
 
 import java.util.ArrayList;
@@ -29,7 +32,14 @@ import static org.junit.jupiter.api.Assertions.assertEquals;
 // resources/application-mock-data-test.properties
 // This config uses an in-memory database
 @ActiveProfiles("mock-data-test")
+
+// This is required to enable WebSocket messaging in tests
+//
+// Without this line, Spring screams about missing SimpMessagingTemplate bean
+@Import(WebSocketConfig.class)
 public class RecipeControllerTest {
+
+    private final SimpMessagingTemplate template;
     private RecipeController controller;
     private List<Recipe> recipes;
     private final RecipeRepository recipeRepository;
@@ -38,8 +48,9 @@ public class RecipeControllerTest {
 
     // Injects a test repository into the test class
     @Autowired
-    public RecipeControllerTest(RecipeRepository recipeRepository) {
+    public RecipeControllerTest(RecipeRepository recipeRepository, SimpMessagingTemplate template) {
         this.recipeRepository = recipeRepository;
+        this.template = template;
     }
 
     @BeforeEach
@@ -48,7 +59,7 @@ public class RecipeControllerTest {
                 .range(0, NUM_RECIPES)
                 .mapToObj(x -> new Recipe(null, "Recipe " + x, List.of(), List.of()))
                 .toList();
-        controller = new RecipeController(recipeRepository);
+        controller = new RecipeController(recipeRepository, template);
         Set<String> tags = info.getTags();
         List<Long> ids = new ArrayList<>();
 
@@ -67,6 +78,7 @@ public class RecipeControllerTest {
 
         // If no tags specified, the repository is initialized as empty.
     }
+
     @Test
     public void createOneRecipe() {
         controller.createRecipe(recipes.getFirst());
@@ -87,6 +99,7 @@ public class RecipeControllerTest {
         // The number of recipes returned is the same as the entire input list
         assertEquals(recipes.size(), controller.getRecipes(Optional.empty()).getBody().size());
     }
+
     @Test
     @Tag("test-from-init-data")
     public void getSomeRecipes() {
@@ -94,6 +107,7 @@ public class RecipeControllerTest {
         // The number of recipes returned is the same as the entire input list
         assertEquals(LIMIT, controller.getRecipes(Optional.of(LIMIT)).getBody().size());
     }
+
     @Test
     @Tag("test-from-init-data")
     @Tag("need-ids")
@@ -104,6 +118,7 @@ public class RecipeControllerTest {
                 recipes.get(CHECK_INDEX),
                 controller.getRecipe(recipeIds.get(CHECK_INDEX)).getBody());
     }
+
     @Test
     public void findOneRecipeNotExists() {
         final int CHECK_INDEX = 3;
@@ -112,6 +127,7 @@ public class RecipeControllerTest {
                 HttpStatus.NOT_FOUND,
                 controller.getRecipe((long) CHECK_INDEX).getStatusCode());
     }
+
     @Test
     @Tag("test-from-init-data")
     @Tag("need-ids")
@@ -121,15 +137,18 @@ public class RecipeControllerTest {
         // The object has been successfully deleted
         assertEquals(HttpStatus.OK, controller.deleteRecipe(recipeIds.get(DELETE_INDEX)).getStatusCode());
     }
+
     @Test
     @Tag("test-from-init-data")
     @Tag("need-ids")
     public void deleteOneRecipeCountGood() {
         final int DELETE_INDEX = 5;
         controller.deleteRecipe(recipeIds.get(DELETE_INDEX));
+
         // The count of items decreased by 1 after the 5th item has been removed.
         assertEquals(recipeIds.size() - 1,  recipeRepository.count());
     }
+
     @Test
     public void deleteOneRecipeFail() {
         final Long DELETE_INDEX = 5L;