From c9dcfeb95a60179d79f979fadfa9a248b809e4dd Mon Sep 17 00:00:00 2001
From: Hoai Viet Nguyen <viet.nguyen@th-koeln.de>
Date: Wed, 9 Apr 2025 11:48:56 +0200
Subject: [PATCH] add echo and simple chat
---
build.gradle | 1 +
.../websocketsdemo/configs/WebSocketConfig.kt | 17 ++++++++++
.../controllers/WelcomeController.kt | 17 ++++++++++
.../gm/websocketsdemo/handlers/EchoHandler.kt | 11 +++++++
.../handlers/SimpleChatHandler.kt | 26 +++++++++++++++
src/main/resources/static/echoclient.html | 32 +++++++++++++++++++
src/main/resources/templates/index.ftlh | 9 ++++++
src/main/resources/templates/layout.ftlh | 27 ++++++++++++++++
src/main/resources/templates/simpleChat.ftlh | 24 ++++++++++++++
9 files changed, 164 insertions(+)
create mode 100644 src/main/kotlin/de/thk/gm/websocketsdemo/configs/WebSocketConfig.kt
create mode 100644 src/main/kotlin/de/thk/gm/websocketsdemo/controllers/WelcomeController.kt
create mode 100644 src/main/kotlin/de/thk/gm/websocketsdemo/handlers/EchoHandler.kt
create mode 100644 src/main/kotlin/de/thk/gm/websocketsdemo/handlers/SimpleChatHandler.kt
create mode 100644 src/main/resources/static/echoclient.html
create mode 100644 src/main/resources/templates/index.ftlh
create mode 100644 src/main/resources/templates/layout.ftlh
create mode 100644 src/main/resources/templates/simpleChat.ftlh
diff --git a/build.gradle b/build.gradle
index faa97d4..efa4a43 100644
--- a/build.gradle
+++ b/build.gradle
@@ -26,6 +26,7 @@ dependencies {
implementation 'org.jetbrains.kotlin:kotlin-reflect'
testImplementation 'org.springframework.boot:spring-boot-starter-test'
testImplementation 'org.jetbrains.kotlin:kotlin-test-junit5'
+ developmentOnly 'org.springframework.boot:spring-boot-devtools'
testRuntimeOnly 'org.junit.platform:junit-platform-launcher'
}
diff --git a/src/main/kotlin/de/thk/gm/websocketsdemo/configs/WebSocketConfig.kt b/src/main/kotlin/de/thk/gm/websocketsdemo/configs/WebSocketConfig.kt
new file mode 100644
index 0000000..71ef4b1
--- /dev/null
+++ b/src/main/kotlin/de/thk/gm/websocketsdemo/configs/WebSocketConfig.kt
@@ -0,0 +1,17 @@
+package de.thk.gm.websocketsdemo.configs
+
+import de.thk.gm.websocketsdemo.handlers.EchoHandler
+import de.thk.gm.websocketsdemo.handlers.SimpleChatHandler
+import org.springframework.context.annotation.Configuration
+import org.springframework.web.socket.config.annotation.EnableWebSocket
+import org.springframework.web.socket.config.annotation.WebSocketConfigurer
+import org.springframework.web.socket.config.annotation.WebSocketHandlerRegistry
+
+@Configuration
+@EnableWebSocket
+class WebSocketConfig () : WebSocketConfigurer {
+ override fun registerWebSocketHandlers(registry: WebSocketHandlerRegistry) {
+ registry.addHandler(EchoHandler(),"/echo")
+ registry.addHandler(SimpleChatHandler(),"/chat")
+ }
+}
\ No newline at end of file
diff --git a/src/main/kotlin/de/thk/gm/websocketsdemo/controllers/WelcomeController.kt b/src/main/kotlin/de/thk/gm/websocketsdemo/controllers/WelcomeController.kt
new file mode 100644
index 0000000..eedc6ec
--- /dev/null
+++ b/src/main/kotlin/de/thk/gm/websocketsdemo/controllers/WelcomeController.kt
@@ -0,0 +1,17 @@
+package de.thk.gm.websocketsdemo.controllers
+
+import org.springframework.stereotype.Controller
+import org.springframework.web.bind.annotation.GetMapping
+
+@Controller
+class WelcomeController {
+ @GetMapping("/")
+ fun index(): String {
+ return "index"
+ }
+
+ @GetMapping("/simplechat")
+ fun simpleChat(): String {
+ return "simpleChat"
+ }
+}
\ No newline at end of file
diff --git a/src/main/kotlin/de/thk/gm/websocketsdemo/handlers/EchoHandler.kt b/src/main/kotlin/de/thk/gm/websocketsdemo/handlers/EchoHandler.kt
new file mode 100644
index 0000000..a93ce45
--- /dev/null
+++ b/src/main/kotlin/de/thk/gm/websocketsdemo/handlers/EchoHandler.kt
@@ -0,0 +1,11 @@
+package de.thk.gm.websocketsdemo.handlers
+
+import org.springframework.web.socket.TextMessage
+import org.springframework.web.socket.WebSocketSession
+import org.springframework.web.socket.handler.TextWebSocketHandler
+
+class EchoHandler : TextWebSocketHandler() {
+ override fun handleTextMessage(session: WebSocketSession, message: TextMessage) {
+ session.sendMessage(message)
+ }
+}
\ No newline at end of file
diff --git a/src/main/kotlin/de/thk/gm/websocketsdemo/handlers/SimpleChatHandler.kt b/src/main/kotlin/de/thk/gm/websocketsdemo/handlers/SimpleChatHandler.kt
new file mode 100644
index 0000000..7bc632e
--- /dev/null
+++ b/src/main/kotlin/de/thk/gm/websocketsdemo/handlers/SimpleChatHandler.kt
@@ -0,0 +1,26 @@
+package de.thk.gm.websocketsdemo.handlers
+
+import org.springframework.web.socket.*
+import org.springframework.web.socket.handler.TextWebSocketHandler
+
+class SimpleChatHandler(): TextWebSocketHandler() {
+ private var sessions : ArrayList<WebSocketSession> = ArrayList()
+ override fun afterConnectionEstablished(session: WebSocketSession) {
+ sessions.add(session)
+ }
+
+ override fun handleTextMessage(session: WebSocketSession, message: TextMessage) {
+ for (session in sessions) {
+ session.sendMessage(message)
+ }
+ }
+
+ override fun afterConnectionClosed(session: WebSocketSession, status: CloseStatus) {
+ for (chatSession in sessions) {
+ if (chatSession.id == session.id) {
+ sessions.remove(chatSession)
+ }
+ }
+
+ }
+}
\ No newline at end of file
diff --git a/src/main/resources/static/echoclient.html b/src/main/resources/static/echoclient.html
new file mode 100644
index 0000000..d1b7cb0
--- /dev/null
+++ b/src/main/resources/static/echoclient.html
@@ -0,0 +1,32 @@
+<!DOCTYPE html>
+<html lang="en">
+<head>
+ <meta charset="UTF-8">
+ <meta name="viewport" content="width=device-width, initial-scale=1.0">
+ <title>Echo Demo</title>
+</head>
+<body>
+<h1>Echo Demo</h1>
+<input type="text" id="message">
+<button type="button" onclick="sendMessage()">Send</button>
+<div id="echo"></div>
+<a href="/">Back</a>
+<script>
+ var ws = new WebSocket("/echo")
+
+ ws.onopen = function (event) {
+ alert("WebSocket successfully established")
+ }
+
+ function sendMessage(){
+ var message = document.getElementById("message").value
+ ws.send(message)
+ }
+
+ ws.onmessage = function (message) {
+ echo.innerHTML += "<p>" + message.data + "</p>"
+ }
+
+</script>
+</body>
+</html>
\ No newline at end of file
diff --git a/src/main/resources/templates/index.ftlh b/src/main/resources/templates/index.ftlh
new file mode 100644
index 0000000..eb82bb2
--- /dev/null
+++ b/src/main/resources/templates/index.ftlh
@@ -0,0 +1,9 @@
+<#import "layout.ftlh" as base>
+<#import "/spring.ftl" as spring />
+<@base.layout>
+ <ul>
+ <li><a href="/echoclient.html">Echo Client</a></li>
+ <li><a href="/simplechat">Simple Chat</a></li>
+ <li><a href="/chatrooms">Chat rooms</a></li>
+ </ul>
+</@base.layout>
diff --git a/src/main/resources/templates/layout.ftlh b/src/main/resources/templates/layout.ftlh
new file mode 100644
index 0000000..ff32195
--- /dev/null
+++ b/src/main/resources/templates/layout.ftlh
@@ -0,0 +1,27 @@
+<#macro layout>
+ <!doctype html>
+ <html lang="en">
+ <head>
+ <meta charset="UTF-8">
+ <meta name="viewport"
+ content="width=device-width, user-scalable=no, initial-scale=1.0, maximum-scale=1.0, minimum-scale=1.0">
+ <meta http-equiv="X-UA-Compatible" content="ie=edge">
+ <title>WebSocket Demos</title>
+ </head>
+ <body>
+ <header>
+ <h1>WebSocket Demos</h1>
+ </header>
+ <hr>
+ <main>
+ <#nested>
+ </main>
+ <hr>
+ <footer>
+ <a href="/#">Imprint</a>
+ <a href="/#">About Us</a>
+ <a href="/#">Privacy</a>
+ </footer>
+ </body>
+ </html>
+</#macro>
\ No newline at end of file
diff --git a/src/main/resources/templates/simpleChat.ftlh b/src/main/resources/templates/simpleChat.ftlh
new file mode 100644
index 0000000..75d821a
--- /dev/null
+++ b/src/main/resources/templates/simpleChat.ftlh
@@ -0,0 +1,24 @@
+<#import "layout.ftlh" as base>
+<@base.layout>
+ <h1>Simple Chat</h1>
+ <div id="chat">
+ </div>
+ <input type="text" id="sender" placeholder="Max Mustermann"><br>
+ <input type="text" id="text" placeholder="Message...">
+ <button type="button" onclick="sendMessage()">Send</button>
+ <script>
+ var ws = new WebSocket("/chat")
+ var chat = document.getElementById("chat")
+ ws.onmessage = function (message) {
+ var chatMessage = JSON.parse(message.data)
+ chat.innerHTML += "<p><b>" +chatMessage.sender+ "</b>:" + chatMessage.text + "</p>"
+ }
+ function sendMessage(){
+ var text = document.getElementById("text").value
+ var sender = document.getElementById("sender").value
+ var chatMessage = {"sender": sender, "text":text}
+ ws.send(JSON.stringify(chatMessage))
+ }
+
+ </script>
+</@base.layout>
\ No newline at end of file
--
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