2021-08-05

build.gradle.kts

@@ -1,7 +1,7 @@
 /*
- * Spring-boot Examples
+ * Examples for Spring-boot
  *
- * Copyright (c) 2021. Elex. All Rights Reserved.
+ * Copyright (c) 2021-2021. Elex. All Rights Reserved.
  * https://www.elex-project.com/
  */
 

buildSrc/src/main/kotlin/elex-spring-boot.gradle.kts

@@ -12,7 +12,7 @@ plugins {
 }
 
 dependencies{
-	implementation("org.jetbrains:annotations:21.0.1")
+	//implementation("org.jetbrains:annotations:21.0.1")
 
 
 }

mqtt/build.gradle.kts

@@ -0,0 +1,27 @@
+/*
+ * Spring-boot Examples
+ *
+ * Copyright (c) 2021. Elex. All Rights Reserved.
+ * https://www.elex-project.com/
+ */
+
+plugins {
+    id("elex-spring-boot")
+
+    id("org.springframework.boot") version "2.5.3"
+    id("io.spring.dependency-management") version "1.0.11.RELEASE"
+}
+
+dependencies {
+    implementation ("org.springframework.boot:spring-boot-starter-web")
+    implementation("org.springframework.boot:spring-boot-starter-mustache")
+
+    implementation ("org.springframework.boot:spring-boot-starter-integration")
+    implementation ("org.springframework.integration:spring-integration-mqtt")
+
+    compileOnly ("org.projectlombok:lombok")
+    developmentOnly ("org.springframework.boot:spring-boot-devtools")
+    annotationProcessor ("org.projectlombok:lombok")
+    testImplementation ("org.springframework.boot:spring-boot-starter-test")
+
+}

mqtt/src/main/java/kr/pe/elex/examples/Application.java

@@ -0,0 +1,18 @@
+/*
+ * Copyright (c) 2021. Elex. All Rights Reserved.
+ * https://www.elex-project.com/
+ */
+
+package kr.pe.elex.examples;
+
+import org.springframework.boot.SpringApplication;
+import org.springframework.boot.autoconfigure.SpringBootApplication;
+
+@SpringBootApplication
+public class Application {
+
+	public static void main(String[] args) {
+		SpringApplication.run(Application.class, args);
+	}
+
+}

mqtt/src/main/java/kr/pe/elex/examples/Config.java

@@ -0,0 +1,31 @@
+/*
+ * Copyright (c) 2021. Elex. All Rights Reserved.
+ * https://www.elex-project.com/
+ */
+
+package kr.pe.elex.examples;
+
+import com.samskivert.mustache.Mustache;
+import org.springframework.boot.autoconfigure.mustache.MustacheEnvironmentCollector;
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
+import org.springframework.core.env.Environment;
+
+@Configuration
+public class Config {
+
+	@Bean
+	public Mustache.Compiler mustacheCompiler(
+			Mustache.TemplateLoader templateLoader,
+			Environment environment) {
+
+		MustacheEnvironmentCollector collector
+				= new MustacheEnvironmentCollector();
+		collector.setEnvironment(environment);
+
+		return Mustache.compiler()
+				.withLoader(templateLoader)
+				.withCollector(collector);
+	}
+
+}

mqtt/src/main/java/kr/pe/elex/examples/HttpController.java

@@ -0,0 +1,35 @@
+/*
+ * Copyright (c) 2021. Elex. All Rights Reserved.
+ * https://www.elex-project.com/
+ */
+
+package kr.pe.elex.examples;
+
+import lombok.extern.slf4j.Slf4j;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.web.bind.annotation.*;
+import org.springframework.web.servlet.ModelAndView;
+
+import java.util.HashMap;
+import java.util.Map;
+
+@Slf4j
+@RestController
+public class HttpController {
+
+	@Autowired
+	private MqttPublisher mqtt;
+
+	@GetMapping("/")
+	public ModelAndView home() {
+		final Map<String, Object> map = new HashMap<>();
+		return new ModelAndView("home", map);
+	}
+
+	@GetMapping("/publish")
+	public void publish(@RequestParam String topic, @RequestParam String message) {
+		log.info("I'll publish a message: {} {}", topic, message);
+
+		mqtt.publish(topic, message);
+	}
+}

mqtt/src/main/java/kr/pe/elex/examples/MqttConfig.java

@@ -0,0 +1,92 @@
+/*
+ * Copyright (c) 2021. Elex. All Rights Reserved.
+ * https://www.elex-project.com/
+ */
+
+package kr.pe.elex.examples;
+
+import org.eclipse.paho.client.mqttv3.MqttAsyncClient;
+import org.eclipse.paho.client.mqttv3.MqttConnectOptions;
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
+import org.springframework.integration.annotation.ServiceActivator;
+import org.springframework.integration.channel.DirectChannel;
+import org.springframework.integration.core.MessageProducer;
+import org.springframework.integration.mqtt.core.DefaultMqttPahoClientFactory;
+import org.springframework.integration.mqtt.inbound.MqttPahoMessageDrivenChannelAdapter;
+import org.springframework.integration.mqtt.outbound.MqttPahoMessageHandler;
+import org.springframework.integration.mqtt.support.DefaultPahoMessageConverter;
+import org.springframework.messaging.MessageChannel;
+import org.springframework.messaging.MessageHandler;
+
+/**
+ * @see "https://docs.spring.io/spring-integration/reference/html/mqtt.html#mqtt"
+ */
+@Configuration
+public class MqttConfig {
+	private static final String HOST = "tcp://localhost:1883";
+	private static final String USERNAME = "elex";
+	private static final String PASSWORD = "test";
+	private static final String CLIENT_ID = "i-am-a-server";
+
+	private static final String TOPIC_FILTER = "#";
+	private static final String TOPIC_FILTER_2 = "$SYS/#";
+
+	private MqttConnectOptions connectOptions() {
+		MqttConnectOptions options = new MqttConnectOptions();
+		options.setCleanSession(true);
+		options.setServerURIs(new String[]{HOST});
+		options.setKeepAliveInterval(10);
+		options.setAutomaticReconnect(true);
+		options.setUserName(USERNAME);
+		options.setPassword(PASSWORD.toCharArray());
+		return options;
+	}
+
+	@Bean
+	public DefaultMqttPahoClientFactory defaultMqttPahoClientFactory() {
+		DefaultMqttPahoClientFactory clientFactory = new DefaultMqttPahoClientFactory();
+		clientFactory.setConnectionOptions(connectOptions());
+		return clientFactory;
+	}
+
+	@Bean
+	public MessageChannel mqttInputChannel() {
+		return new DirectChannel();
+	}
+
+	@Bean
+	public MessageProducer inboundChannel(DefaultMqttPahoClientFactory clientFactory) {
+		MqttPahoMessageDrivenChannelAdapter adapter =
+				new MqttPahoMessageDrivenChannelAdapter(HOST, CLIENT_ID, clientFactory,
+						TOPIC_FILTER, TOPIC_FILTER_2);
+		adapter.setCompletionTimeout(5000);
+		adapter.setConverter(new DefaultPahoMessageConverter());
+		adapter.setQos(1);
+		adapter.setOutputChannel(mqttInputChannel());
+		return adapter;
+	}
+
+	@Bean
+	@ServiceActivator(inputChannel = "mqttInputChannel")
+	public MessageHandler messageHandler() {
+		return new MqttMessageHandler();
+	}
+
+	@Bean
+	public MessageChannel mqttOutboundChannel() {
+		return new DirectChannel();
+	}
+
+	@Bean
+	@ServiceActivator(inputChannel = "mqttOutboundChannel")
+	public MessageHandler mqttOutbound(DefaultMqttPahoClientFactory clientFactory) {
+		MqttPahoMessageHandler messageHandler =
+				new MqttPahoMessageHandler(CLIENT_ID + MqttAsyncClient.generateClientId(),
+						clientFactory);
+		messageHandler.setAsync(true);
+		messageHandler.setDefaultQos(1);
+		return messageHandler;
+	}
+
+}

mqtt/src/main/java/kr/pe/elex/examples/MqttMessageHandler.java

@@ -0,0 +1,29 @@
+/*
+ * Copyright (c) 2021. Elex. All Rights Reserved.
+ * https://www.elex-project.com/
+ */
+
+package kr.pe.elex.examples;
+
+import lombok.extern.slf4j.Slf4j;
+import org.springframework.integration.mqtt.support.MqttHeaders;
+import org.springframework.messaging.Message;
+import org.springframework.messaging.MessageHandler;
+import org.springframework.messaging.MessagingException;
+
+@Slf4j
+public class MqttMessageHandler implements MessageHandler {
+
+	/**
+	 * 구독 중인 MQTT 메시지는 여기서 받는다.
+	 *
+	 * @param message
+	 * @throws MessagingException
+	 */
+	@Override
+	public void handleMessage(Message<?> message) throws MessagingException {
+		String topic = (String) message.getHeaders().get(MqttHeaders.RECEIVED_TOPIC);
+		log.info("MQTT Rx: {} {}", topic, message.getPayload());
+
+	}
+}

mqtt/src/main/java/kr/pe/elex/examples/MqttPublisher.java

@@ -0,0 +1,23 @@
+/*
+ * Copyright (c) 2021. Elex. All Rights Reserved.
+ * https://www.elex-project.com/
+ */
+
+package kr.pe.elex.examples;
+
+import org.springframework.integration.annotation.MessagingGateway;
+import org.springframework.integration.mqtt.support.MqttHeaders;
+import org.springframework.messaging.handler.annotation.Header;
+
+@MessagingGateway(defaultRequestChannel = "mqttOutboundChannel")
+public interface MqttPublisher {
+
+	/**
+	 * MQTT 메시지는 여기서 발행한다.
+	 *
+	 * @param topic
+	 * @param payload
+	 */
+	void publish(@Header(MqttHeaders.TOPIC) String topic, String payload);
+
+}

mqtt/src/main/java/kr/pe/elex/examples/package-info.java

@@ -0,0 +1,6 @@
+/*
+ * Copyright (c) 2021. Elex. All Rights Reserved.
+ * https://www.elex-project.com/
+ */
+
+package kr.pe.elex.examples;

mqtt/src/main/resources/application.properties

@@ -0,0 +1,4 @@
+#
+# Copyright (c) 2021. Elex. All Rights Reserved.
+# https://www.elex-project.com/
+#

mqtt/src/main/resources/logback-spring.xml

@@ -0,0 +1,19 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!--
+  ~ Copyright (c) 2021. Elex. All Rights Reserved.
+  ~ https://www.elex-project.com/
+  -->
+
+<configuration>
+
+	<appender name="CONSOLE" class="ch.qos.logback.core.ConsoleAppender">
+		<encoder>
+			<pattern>%d{HH:mm:ss.SSS} [%thread] %-5level %logger{15} - %msg%n</pattern>
+		</encoder>
+	</appender>
+
+	<root level="info">
+		<appender-ref ref="CONSOLE"/>
+	</root>
+
+</configuration>

mqtt/src/main/resources/templates/home.mustache

@@ -0,0 +1,15 @@
+<html>
+<head>
+	<meta charset="utf-8">
+	<meta name="viewport" content="width=device-width, initial-scale=1">
+	<title>MQTT Spring-boot Integration Examples</title>
+</head>
+<body>
+	<h1>MQTT Spring-boot Integration Examples</h1>
+	<dl>
+		<dt>Usage</dt>
+		<dd><code>/publish?topic=TOPIC&message=MESSAGE</code></dd>
+	</dl>
+	<p>Copyright $copy; 2021 Elex Project. All Rights Reserved.</p>
+</body>
+</html>

mqtt/src/test/java/kr/pe/elex/examples/ApplicationTests.java

@@ -0,0 +1,18 @@
+/*
+ * Copyright (c) 2021. Elex. All Rights Reserved.
+ * https://www.elex-project.com/
+ */
+
+package kr.pe.elex.examples;
+
+import org.junit.jupiter.api.Test;
+import org.springframework.boot.test.context.SpringBootTest;
+
+@SpringBootTest
+class ApplicationTests {
+
+	@Test
+	void contextLoads() {
+	}
+
+}

restful/build.gradle.kts

@@ -0,0 +1,27 @@
+/*
+ * Spring-boot Examples
+ *
+ * Copyright (c) 2021. Elex. All Rights Reserved.
+ * https://www.elex-project.com/
+ */
+
+plugins {
+    id("elex-spring-boot")
+
+    id("org.springframework.boot") version "2.5.3"
+    id("io.spring.dependency-management") version "1.0.11.RELEASE"
+}
+
+dependencies {
+    implementation("org.springframework.boot:spring-boot-starter-web")
+    implementation("org.springframework.boot:spring-boot-starter-mustache")
+
+    compileOnly("org.projectlombok:lombok")
+    developmentOnly("org.springframework.boot:spring-boot-devtools")
+
+    annotationProcessor("org.springframework.boot:spring-boot-configuration-processor")
+    annotationProcessor("org.projectlombok:lombok")
+
+    testImplementation("org.springframework.boot:spring-boot-starter-test")
+
+}

restful/src/main/java/kr/pe/elex/examples/Application.java

@@ -0,0 +1,13 @@
+package kr.pe.elex.examples;
+
+import org.springframework.boot.SpringApplication;
+import org.springframework.boot.autoconfigure.SpringBootApplication;
+
+@SpringBootApplication
+public class Application {
+
+	public static void main(String[] args) {
+		SpringApplication.run(Application.class, args);
+	}
+
+}

restful/src/main/java/kr/pe/elex/examples/MainController.java

@@ -0,0 +1,23 @@
+package kr.pe.elex.examples;
+
+import lombok.extern.slf4j.Slf4j;
+import org.springframework.http.ResponseEntity;
+import org.springframework.util.MimeType;
+import org.springframework.util.MimeTypeUtils;
+import org.springframework.web.bind.annotation.GetMapping;
+import org.springframework.web.bind.annotation.PathVariable;
+import org.springframework.web.bind.annotation.RestController;
+
+import java.util.Random;
+
+@Slf4j
+@RestController
+public class MainController {
+
+	@GetMapping(path = "/{name}", produces = {MimeTypeUtils.APPLICATION_JSON_VALUE})
+	public ResponseEntity<Person> home(@PathVariable String name) {
+
+		return ResponseEntity
+				.ok(new Person(name, new Random().nextInt()));
+	}
+}

restful/src/main/java/kr/pe/elex/examples/Person.java

@@ -0,0 +1,14 @@
+package kr.pe.elex.examples;
+
+import com.fasterxml.jackson.annotation.JsonProperty;
+import lombok.AllArgsConstructor;
+import lombok.Data;
+
+@Data
+@AllArgsConstructor
+public class Person {
+	@JsonProperty
+	private String name;
+	@JsonProperty
+	private int age;
+}

restful/src/main/java/kr/pe/elex/examples/package-info.java

@@ -0,0 +1 @@
+package kr.pe.elex.examples;

restful/src/main/resources/application.properties

@@ -0,0 +1 @@
+

settings.gradle.kts

@@ -6,4 +6,5 @@
  */
 
 rootProject.name = "spring-boot-examples"
-include("file-upload", "security", "security-with-jpa", "validation", "testing")
+include("file-upload", "security", "security-with-jpa", "validation", "testing",
+    "mqtt", "websocket", "restful")

websocket/build.gradle.kts

@@ -0,0 +1,25 @@
+/*
+ * Spring-boot Examples
+ *
+ * Copyright (c) 2021. Elex. All Rights Reserved.
+ * https://www.elex-project.com/
+ */
+
+plugins {
+    id("elex-spring-boot")
+
+    id("org.springframework.boot") version "2.5.3"
+    id("io.spring.dependency-management") version "1.0.11.RELEASE"
+}
+
+dependencies {
+    implementation ("org.springframework.boot:spring-boot-starter-web")
+    implementation("org.springframework.boot:spring-boot-starter-mustache")
+
+    implementation("org.springframework.boot:spring-boot-starter-websocket")
+
+    compileOnly ("org.projectlombok:lombok")
+    developmentOnly ("org.springframework.boot:spring-boot-devtools")
+    annotationProcessor ("org.projectlombok:lombok")
+    testImplementation ("org.springframework.boot:spring-boot-starter-test")
+}

websocket/src/main/java/kr/pe/elex/examples/Application.java

@@ -0,0 +1,18 @@
+/*
+ * Copyright (c) 2021. Elex. All Rights Reserved.
+ * https://www.elex-project.com/
+ */
+
+package kr.pe.elex.examples;
+
+import org.springframework.boot.SpringApplication;
+import org.springframework.boot.autoconfigure.SpringBootApplication;
+
+@SpringBootApplication
+public class Application {
+
+	public static void main(String[] args) {
+		SpringApplication.run(Application.class, args);
+	}
+
+}

websocket/src/main/java/kr/pe/elex/examples/Config.java

@@ -0,0 +1,31 @@
+/*
+ * Copyright (c) 2021. Elex. All Rights Reserved.
+ * https://www.elex-project.com/
+ */
+
+package kr.pe.elex.examples;
+
+import com.samskivert.mustache.Mustache;
+import org.springframework.boot.autoconfigure.mustache.MustacheEnvironmentCollector;
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
+import org.springframework.core.env.Environment;
+
+@Configuration
+public class Config {
+
+	@Bean
+	public Mustache.Compiler mustacheCompiler(
+			Mustache.TemplateLoader templateLoader,
+			Environment environment) {
+
+		MustacheEnvironmentCollector collector
+				= new MustacheEnvironmentCollector();
+		collector.setEnvironment(environment);
+
+		return Mustache.compiler()
+				.withLoader(templateLoader)
+				.withCollector(collector);
+	}
+
+}

websocket/src/main/java/kr/pe/elex/examples/HttpController.java

@@ -0,0 +1,27 @@
+/*
+ * Copyright (c) 2021. Elex. All Rights Reserved.
+ * https://www.elex-project.com/
+ */
+
+package kr.pe.elex.examples;
+
+import lombok.extern.slf4j.Slf4j;
+import org.springframework.web.bind.annotation.GetMapping;
+import org.springframework.web.bind.annotation.RestController;
+import org.springframework.web.servlet.ModelAndView;
+
+import java.util.HashMap;
+import java.util.Map;
+
+@Slf4j
+@RestController
+public class HttpController {
+
+	@GetMapping("/")
+	public ModelAndView home() {
+		final Map<String, Object> map = new HashMap<>();
+		map.put("title", "Websocket Test");
+		return new ModelAndView("home", map);
+	}
+
+}

websocket/src/main/java/kr/pe/elex/examples/WebSocketConfig.java

@@ -0,0 +1,26 @@
+/*
+ * Copyright (c) 2021. Elex. All Rights Reserved.
+ * https://www.elex-project.com/
+ */
+
+package kr.pe.elex.examples;
+
+import lombok.RequiredArgsConstructor;
+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
+@RequiredArgsConstructor
+public class WebSocketConfig implements WebSocketConfigurer {
+	private final WebSocketHandler webSocketHandler;
+
+	@Override
+	public void registerWebSocketHandlers(WebSocketHandlerRegistry registry) {
+		registry.addHandler(webSocketHandler, "/websocket");
+				//.setAllowedOrigins("*")
+               // .withSockJS();
+	}
+}

websocket/src/main/java/kr/pe/elex/examples/WebSocketHandler.java

@@ -0,0 +1,60 @@
+/*
+ * Copyright (c) 2021. Elex. All Rights Reserved.
+ * https://www.elex-project.com/
+ */
+
+package kr.pe.elex.examples;
+
+import lombok.RequiredArgsConstructor;
+import lombok.extern.slf4j.Slf4j;
+import org.springframework.stereotype.Component;
+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 java.io.IOException;
+import java.util.Set;
+import java.util.concurrent.ConcurrentHashMap;
+
+@Slf4j
+@Component
+@RequiredArgsConstructor
+public class WebSocketHandler extends TextWebSocketHandler {
+	private static Set<WebSocketSession> sessions = new ConcurrentHashMap().newKeySet();
+
+	public static void publish(String message) throws IOException {
+		for (WebSocketSession item : sessions) {
+			try {
+				item.sendMessage(new TextMessage(message));
+			} catch (Throwable e) {
+				log.error("Couldn't send message over websocket.", e);
+			}
+		}
+	}
+
+	@Override
+	public void afterConnectionEstablished(WebSocketSession session) throws Exception {
+		super.afterConnectionEstablished(session);
+		sessions.add(session);
+		log.info("Client({}) connected.", session.getRemoteAddress());
+	}
+
+	@Override
+	protected void handleTextMessage(WebSocketSession session, TextMessage message) throws Exception {
+		log.info("Message from client({}):{}", session.getRemoteAddress(), message.getPayload());
+		for (WebSocketSession webSocketSession : sessions) {
+			//if (session == webSocketSession) continue;
+			String msg = message.getPayload().toUpperCase();
+			webSocketSession.sendMessage(new TextMessage(msg));
+		}
+	}
+
+	@Override
+	public void afterConnectionClosed(WebSocketSession session, CloseStatus status) throws Exception {
+		super.afterConnectionClosed(session, status);
+		sessions.remove(session);
+		log.info("Client({}) disconnect.", session.getRemoteAddress());
+	}
+
+}

websocket/src/main/java/kr/pe/elex/examples/package-info.java

@@ -0,0 +1,6 @@
+/*
+ * Copyright (c) 2021. Elex. All Rights Reserved.
+ * https://www.elex-project.com/
+ */
+
+package kr.pe.elex.examples;

websocket/src/main/resources/application.properties

@@ -0,0 +1,4 @@
+#
+# Copyright (c) 2021. Elex. All Rights Reserved.
+# https://www.elex-project.com/
+#

websocket/src/main/resources/logback-spring.xml

@@ -0,0 +1,19 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!--
+  ~ Copyright (c) 2021. Elex. All Rights Reserved.
+  ~ https://www.elex-project.com/
+  -->
+
+<configuration>
+
+	<appender name="CONSOLE" class="ch.qos.logback.core.ConsoleAppender">
+		<encoder>
+			<pattern>%d{HH:mm:ss.SSS} [%thread] %-5level %logger{15} - %msg%n</pattern>
+		</encoder>
+	</appender>
+
+	<root level="info">
+		<appender-ref ref="CONSOLE"/>
+	</root>
+
+</configuration>

websocket/src/main/resources/templates/home.mustache

@@ -0,0 +1,108 @@
+<html lang="ko">
+<head>
+	<meta charset="utf-8">
+	<meta name="viewport" content="width=device-width, initial-scale=1">
+	<title>{{title}}</title>
+	<style>
+	* {
+		box-sizing: border-box;
+	}
+	body {
+		margin:0; padding:0; border:0;
+	}
+	.layout {
+		display: grid;
+		grid-template-rows: 64px 1fr;
+		grid-template-columns: 1fr;
+		grid-template-areas: "controls" "textpane";
+		width: 100%; height: 100%;
+	}
+	.row{
+		display: flex;
+		flex-direction: row;
+		align-items: center;
+		grid-area: controls;
+		background-color: orange;
+		padding: 0 16px;
+	}
+	.row h1{
+		flex-grow: 1;
+	}
+	.text-pane {
+		grid-area: textpane;
+		width: 100%; height: 100%;
+	}
+	textarea {
+		width: 100%; height: 100%;
+		overflow: auto;
+		resize: none;
+	}
+	</style>
+	<script>
+	const log = function(msg){
+		const ta = document.querySelector("#text-area");
+		ta.append(new Date().toLocaleString());
+		ta.append("\t");
+		ta.append(msg);
+		ta.append("\r\n");
+		ta.scrollTop = ta.scrollHeight;
+	};
+	const WS = {
+		websocket: null,
+		connect: function(){
+			this.websocket = new WebSocket("ws://localhost:8080/websocket");
+			this.websocket.onopen = function(ev){
+				console.log("Connected.");
+				log("Connected.");
+			};
+			this.websocket.onclose = function(ev){
+				console.log("Closed.");
+				log("Closed.");
+			};
+			this.websocket.onmessage = function(ev){
+				console.log("Rx: " + ev.data);
+				log("Rx: " + ev.data);
+			};
+			this.websocket.onerror = function(ev){
+				console.log("Error! " + ev.data);
+				log("Error! " + ev.data);
+			}
+		},
+		disconnect: function(){
+			if (!this.websocket) websocket.close();
+			console.log("Disconnected.");
+			log("Disconnected.");
+		},
+		sendMessage: function(message){
+			this.websocket.send(message);
+			console.log("Tx: " + message);
+			log("Tx: " + message);
+		}
+	};
+
+	window.addEventListener('DOMContentLoaded', (event) => {
+		WS.connect();
+	});
+
+	const send = function(){
+		const msg = document.querySelector("#text-to-send").value;
+		WS.sendMessage(msg);
+	};
+
+	</script>
+</head>
+<body>
+	<div class="layout">
+		<div class="row">
+			<h1>{{title}}</h1>
+			<input id="text-to-send" type="text" />
+			<button onclick="send();">Send</button>
+			<button onclick="WS.connect();">Connect</button>
+			<button onclick="WS.disconnect();">Disconnect</button>
+		</div>
+		<div class="text-pane">
+			<textarea id="text-area"></textarea>
+		</div>
+	</div>
+</body>
+</html>

websocket/src/test/java/kr/pe/elex/examples/ApplicationTests.java

@@ -0,0 +1,18 @@
+/*
+ * Copyright (c) 2021. Elex. All Rights Reserved.
+ * https://www.elex-project.com/
+ */
+
+package kr.pe.elex.examples;
+
+import org.junit.jupiter.api.Test;
+import org.springframework.boot.test.context.SpringBootTest;
+
+@SpringBootTest
+class ApplicationTests {
+
+	@Test
+	void contextLoads() {
+	}
+
+}