implement functionality which make chat messages persistent

build.gradle

@@ -27,6 +27,7 @@ dependencies {
     implementation 'org.springframework.boot:spring-boot-starter-data-jpa'
     implementation 'org.springframework.boot:spring-boot-starter-validation'
     testImplementation 'org.springframework.boot:spring-boot-starter-test'
+    implementation 'org.json:org.json:chargebee-1.0'
     testImplementation 'org.jetbrains.kotlin:kotlin-test-junit5'
     developmentOnly 'org.springframework.boot:spring-boot-devtools'
     runtimeOnly 'com.h2database:h2'

src/main/kotlin/de/thk/gm/websocketsdemo/configs/WebSocketsConfig.kt

@@ -3,6 +3,8 @@ package de.thk.gm.websocketsdemo.configs
 import de.thk.gm.websocketsdemo.handlers.ChatRoomsHandler
 import de.thk.gm.websocketsdemo.handlers.EchoHandler
 import de.thk.gm.websocketsdemo.handlers.SimpleChatHandler
+import de.thk.gm.websocketsdemo.services.ChatMessageService
+import de.thk.gm.websocketsdemo.services.ChatRoomsService
 import org.springframework.context.annotation.Configuration
 import org.springframework.web.socket.WebSocketHandler
 import org.springframework.web.socket.config.annotation.EnableWebSocket
@@ -11,10 +13,10 @@ import org.springframework.web.socket.config.annotation.WebSocketHandlerRegistry
 
 @Configuration
 @EnableWebSocket
-class WebSocketsConfig(): WebSocketConfigurer {
+class WebSocketsConfig(private val chatMessageService: ChatMessageService, private val chatRoomsService: ChatRoomsService): WebSocketConfigurer {
     override fun registerWebSocketHandlers(registry: WebSocketHandlerRegistry) {
         registry.addHandler(EchoHandler(), "/echo").setAllowedOrigins("*")
         registry.addHandler(SimpleChatHandler(), "/chat")
-        registry.addHandler(ChatRoomsHandler(),"/rooms")
+        registry.addHandler(ChatRoomsHandler(chatRoomsService, chatMessageService),"/rooms")
     }
 }
\ No newline at end of file

src/main/kotlin/de/thk/gm/websocketsdemo/controllers/ChatRoomsController.kt

@@ -2,6 +2,7 @@ package de.thk.gm.websocketsdemo.controllers
 
 import de.thk.gm.websocketsdemo.dtos.ChatRoomDto
 import de.thk.gm.websocketsdemo.models.ChatRoom
+import de.thk.gm.websocketsdemo.services.ChatMessageService
 import de.thk.gm.websocketsdemo.services.ChatRoomsService
 import org.springframework.stereotype.Controller
 import org.springframework.ui.Model
@@ -10,7 +11,7 @@ import java.util.*
 
 @Controller
 @RequestMapping("/chatrooms")
-class ChatRoomsController (private val chatRoomsService: ChatRoomsService) {
+class ChatRoomsController (private val chatRoomsService: ChatRoomsService, private val chatMessageService: ChatMessageService) {
 
     @GetMapping
     fun getChatRooms(model: Model): String {
@@ -28,8 +29,11 @@ class ChatRoomsController (private val chatRoomsService: ChatRoomsService) {
 
     @GetMapping("/{id}")
     fun getChatRoom(@PathVariable("id") id: UUID, model: Model): String {
+
         var chatRoom = chatRoomsService.getChatRoomById(id)
+        var chatMessages = chatMessageService.getChatMessagesByChatRoomId(id)
         model.addAttribute("chatRoom", chatRoom)
+        model.addAttribute("chatMessages", chatMessages)
         return "chatRooms/showChatRoom"
     }
 }
\ No newline at end of file

src/main/kotlin/de/thk/gm/websocketsdemo/handlers/ChatRoomsHandler.kt

 package de.thk.gm.websocketsdemo.handlers
 
+import de.thk.gm.websocketsdemo.models.ChatMessage
+import de.thk.gm.websocketsdemo.services.ChatMessageService
+import de.thk.gm.websocketsdemo.services.ChatRoomsService
+import org.json.JSONObject
 import org.springframework.web.socket.CloseStatus
 import org.springframework.web.socket.TextMessage
 import org.springframework.web.socket.WebSocketSession
 import org.springframework.web.socket.handler.TextWebSocketHandler
 import org.springframework.web.util.UriComponents
 import org.springframework.web.util.UriComponentsBuilder
+import java.util.*
+import kotlin.collections.ArrayList
+import kotlin.collections.HashMap
 
-class ChatRoomsHandler : TextWebSocketHandler() {
+class ChatRoomsHandler (private val chatRoomsService: ChatRoomsService, private val chatMessageService: ChatMessageService) : TextWebSocketHandler() {
     private val hashMapOfSessions : HashMap<String, ArrayList<WebSocketSession>> = HashMap()
     override fun afterConnectionEstablished(session: WebSocketSession) {
         var uri : UriComponents = UriComponentsBuilder.fromUri(session.uri!!).build()
@@ -26,6 +33,15 @@ class ChatRoomsHandler : TextWebSocketHandler() {
         var uri : UriComponents = UriComponentsBuilder.fromUri(session.uri!!).build()
         var id  = uri.queryParams.getFirst("id")
         var sessions = hashMapOfSessions[id]
+        val chatMessageJSONObject = JSONObject(message.payload)
+
+        val chatRoom = chatRoomsService.getChatRoomById(UUID.fromString(id));
+        val chatMessage = ChatMessage()
+        chatMessage.chatRoom = chatRoom
+        chatMessage.text = chatMessageJSONObject.getString("text")
+        chatMessage.username = chatMessageJSONObject.getString("username")
+        chatMessageService.save(chatMessage)
+
         if(sessions != null) {
             for (chatSession in sessions) {
                 chatSession.sendMessage(message)

src/main/kotlin/de/thk/gm/websocketsdemo/models/ChatMessage.kt

+package de.thk.gm.websocketsdemo.models
+
+import jakarta.persistence.Entity
+import jakarta.persistence.Id
+import jakarta.persistence.ManyToOne
+import java.util.*
+
+@Entity
+class ChatMessage {
+    @Id
+    val id: UUID = UUID.randomUUID()
+
+    var username: String? = null
+    var text: String? = null
+    var createdAt: Date = Date()
+
+    @ManyToOne
+    var chatRoom: ChatRoom? = null
+}
\ No newline at end of file

src/main/kotlin/de/thk/gm/websocketsdemo/repositories/ChatMessageRepository.kt

+package de.thk.gm.websocketsdemo.repositories
+
+import de.thk.gm.websocketsdemo.models.ChatMessage
+import de.thk.gm.websocketsdemo.models.ChatRoom
+import org.springframework.data.repository.CrudRepository
+import org.springframework.stereotype.Repository
+import java.util.*
+
+@Repository
+interface ChatMessageRepository : CrudRepository<ChatMessage, UUID> {
+    fun findChatMessagesByChatRoomOrderByCreatedAt(chatRoom: ChatRoom): List<ChatMessage>
+}
\ No newline at end of file

src/main/kotlin/de/thk/gm/websocketsdemo/services/ChatMessageService.kt

+package de.thk.gm.websocketsdemo.services
+
+import de.thk.gm.websocketsdemo.models.ChatMessage
+import java.util.*
+
+interface ChatMessageService {
+    fun getChatMessagesByChatRoomId(roomId: UUID): List<ChatMessage>
+    fun save(chatMessage: ChatMessage)
+}
\ No newline at end of file

src/main/kotlin/de/thk/gm/websocketsdemo/services/ChatMessageServiceImpl.kt

+package de.thk.gm.websocketsdemo.services
+
+import de.thk.gm.websocketsdemo.models.ChatMessage
+import de.thk.gm.websocketsdemo.repositories.ChatMessageRepository
+import de.thk.gm.websocketsdemo.repositories.ChatRoomsRepository
+import org.springframework.stereotype.Service
+import java.util.*
+
+@Service
+class ChatMessageServiceImpl (private val chatMessageRepository: ChatMessageRepository, private val chatRoomsRepository: ChatRoomsRepository) : ChatMessageService {
+    override fun getChatMessagesByChatRoomId(roomId: UUID): List<ChatMessage> {
+        val chatRoom = chatRoomsRepository.findById(roomId).orElse(null)
+        if(chatRoom != null) {
+            return chatMessageRepository.findChatMessagesByChatRoomOrderByCreatedAt(chatRoom)
+        } else {
+            return listOf()
+        }
+
+    }
+
+    override fun save(chatMessage: ChatMessage) {
+       chatMessageRepository.save(chatMessage)
+    }
+}
\ No newline at end of file

src/main/resources/templates/chatRooms/showChatRoom.ftlh

@@ -13,7 +13,11 @@
     <input type="text" id="text" placeholder="message">
     <br>
     <button onclick="sendMessage()">Send</button>
-    <div id="chat"></div>
+    <div id="chat">
+        <#list chatMessages as chatMessage>
+            <p><b>${chatMessage.username}:</b>${chatMessage.text}</p>
+        </#list>
+    </div>
     <script>
         var ws = new WebSocket("/rooms?id=${chatRoom.id}")
         var chat = document.getElementById("chat")