INTSAMPLES-137: Add WebSockets sample

JIRA: https://jira.spring.io/browse/INTSAMPLES-137

**DO NOT MERGE YET**

Depends on spring-projects/spring-integration#1274

basic/web-sockets/README.md

@@ -0,0 +1,27 @@
+WebSockets Sample
+==============
+
+This example demonstrates Standard WebSocket protocol (without any sub-protocols) with Spring Integration Adapters.
+It just sends current time from the server to all connected clients.
+
+## Server
+
+The server is presented only with single `org.springframework.integration.samples.websocket.standard.server.Application`
+class, which is based on the Spring Boot AutoConfiguration and Spring Integration Java & Annotation configuration.
+It is a `main` and starts embedded Tomcat on default `8080` port. The WebSocket endpoint is mapped to the `/time` path.
+
+## Java Client
+
+The `org.springframework.integration.samples.websocket.standard.client.Application` represents simple Java application,
+ which starts an integration flow (`client-context.xml`), connects to the WebSocket server and prints `Message`s to the 
+ logs, which are received over WebSocket.
+
+## Browser Client
+
+The `index.html` in the `resource` directory of this project demonstrates a JavaScript `SockJS` client, which connects
+to our server and just prints its messages in the middle of page.
+
+## Test Case
+
+The `org.springframework.integration.samples.websocket.standard.ApplicationTests` demonstrates the Spring Boot test 
+framework and starts Server & Client to check, that the last one receives correct data.

basic/web-sockets/src/main/java/org/springframework/integration/samples/websocket/standard/client/Application.java

@@ -0,0 +1,34 @@
+/*
+ * Copyright 2014 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.springframework.integration.samples.websocket.standard.client;
+
+import org.springframework.context.ConfigurableApplicationContext;
+import org.springframework.context.support.ClassPathXmlApplicationContext;
+
+/**
+ * @author Artem Bilan
+ * @since 3.0
+ */
+public class Application {
+
+	public static void main(String[] args) throws Exception {
+		ConfigurableApplicationContext ctx = new ClassPathXmlApplicationContext("client-context.xml", Application.class);
+		System.in.read();
+		ctx.close();
+	}
+
+}

basic/web-sockets/src/main/java/org/springframework/integration/samples/websocket/standard/server/Application.java

@@ -0,0 +1,141 @@
+/*
+ * Copyright 2014 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.springframework.integration.samples.websocket.standard.server;
+
+import java.text.DateFormat;
+import java.util.Collections;
+import java.util.Date;
+import java.util.Iterator;
+import java.util.concurrent.Executors;
+
+import org.springframework.boot.SpringApplication;
+import org.springframework.boot.autoconfigure.EnableAutoConfiguration;
+import org.springframework.context.ConfigurableApplicationContext;
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
+import org.springframework.integration.annotation.InboundChannelAdapter;
+import org.springframework.integration.annotation.Poller;
+import org.springframework.integration.annotation.ServiceActivator;
+import org.springframework.integration.annotation.Transformer;
+import org.springframework.integration.channel.DirectChannel;
+import org.springframework.integration.channel.ExecutorChannel;
+import org.springframework.integration.channel.PublishSubscribeChannel;
+import org.springframework.integration.core.MessageSource;
+import org.springframework.integration.handler.LoggingHandler;
+import org.springframework.integration.splitter.DefaultMessageSplitter;
+import org.springframework.integration.transformer.AbstractPayloadTransformer;
+import org.springframework.integration.transformer.HeaderEnricher;
+import org.springframework.integration.transformer.support.ExpressionEvaluatingHeaderValueMessageProcessor;
+import org.springframework.integration.websocket.ServerWebSocketContainer;
+import org.springframework.integration.websocket.outbound.WebSocketOutboundMessageHandler;
+import org.springframework.messaging.Message;
+import org.springframework.messaging.MessageChannel;
+import org.springframework.messaging.MessageHandler;
+import org.springframework.messaging.simp.SimpMessageHeaderAccessor;
+import org.springframework.messaging.support.GenericMessage;
+
+/**
+ * @author Artem Bilan
+ * @since 3.0
+ */
+@Configuration
+@EnableAutoConfiguration
+public class Application {
+
+	public static void main(String[] args) throws Exception {
+		ConfigurableApplicationContext ctx = SpringApplication.run(Application.class);
+		System.in.read();
+		ctx.close();
+	}
+
+	@Bean
+	public ServerWebSocketContainer serverWebSocketContainer() {
+		return new ServerWebSocketContainer("/time").withSockJs();
+	}
+
+	@Bean
+	@InboundChannelAdapter(value = "splitChannel", poller = @Poller(fixedDelay = "1000", maxMessagesPerPoll = "1"))
+	public MessageSource<?> webSocketSessionsMessageSource() {
+		return new MessageSource<Iterator<String>>() {
+
+			@Override
+			public Message<Iterator<String>> receive() {
+				return new GenericMessage<Iterator<String>>(serverWebSocketContainer().getSessions().keySet().iterator());
+			}
+
+		};
+	}
+
+	@Bean
+	public MessageChannel splitChannel() {
+		return new DirectChannel();
+	}
+
+	@Bean
+	@ServiceActivator(inputChannel = "splitChannel")
+	public MessageHandler splitter() {
+		DefaultMessageSplitter splitter = new DefaultMessageSplitter();
+		splitter.setOutputChannelName("headerEnricherChannel");
+		return splitter;
+	}
+
+	@Bean
+	public MessageChannel headerEnricherChannel() {
+		return new ExecutorChannel(Executors.newCachedThreadPool());
+	}
+
+	@Bean
+	@Transformer(inputChannel = "headerEnricherChannel", outputChannel = "transformChannel")
+	public HeaderEnricher headerEnricher() {
+		return new HeaderEnricher(Collections.singletonMap(SimpMessageHeaderAccessor.SESSION_ID_HEADER,
+				new ExpressionEvaluatingHeaderValueMessageProcessor<Object>("payload", null)));
+	}
+
+	@Bean
+	@Transformer(inputChannel = "transformChannel", outputChannel = "sendTimeChannel")
+	public AbstractPayloadTransformer<?, ?> transformer() {
+		return new AbstractPayloadTransformer<Object, Object>() {
+			@Override
+			protected Object transformPayload(Object payload) throws Exception {
+				return DateFormat.getDateTimeInstance(DateFormat.LONG, DateFormat.DEFAULT).format(new Date());
+			}
+
+		};
+	}
+
+
+	@Bean
+	public MessageChannel sendTimeChannel() {
+		return new PublishSubscribeChannel();
+	}
+
+
+	@Bean
+	@ServiceActivator(inputChannel = "sendTimeChannel")
+	public MessageHandler webSocketOutboundAdapter() {
+		return new WebSocketOutboundMessageHandler(serverWebSocketContainer());
+	}
+
+	@Bean
+	@ServiceActivator(inputChannel = "sendTimeChannel")
+	public MessageHandler loggingChannelAdapter() {
+		LoggingHandler loggingHandler = new LoggingHandler("info");
+		loggingHandler.setExpression("'The time ' + payload + ' has been sent to the WebSocketSession ' + headers.simpSessionId");
+		return loggingHandler;
+	}
+
+}

basic/web-sockets/src/main/resources/org/springframework/integration/samples/websocket/standard/client/client-context.xml

@@ -0,0 +1,24 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<beans xmlns="http://www.springframework.org/schema/beans"
+	   xmlns:int="http://www.springframework.org/schema/integration"
+	   xmlns:int-websocket="http://www.springframework.org/schema/integration/websocket"
+	   xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+	   xsi:schemaLocation="http://www.springframework.org/schema/beans
+	   http://www.springframework.org/schema/beans/spring-beans.xsd
+	   http://www.springframework.org/schema/integration
+			http://www.springframework.org/schema/integration/spring-integration.xsd
+			http://www.springframework.org/schema/integration/websocket
+			http://www.springframework.org/schema/integration/websocket/spring-integration-websocket.xsd">
+
+	<bean id="webSocketClient" class="org.springframework.web.socket.client.standard.StandardWebSocketClient"/>
+
+	<int-websocket:client-container id="clientWebSocketContainer"
+									client="webSocketClient"
+									uri="ws://localhost:8080/time/websocket"/>
+
+	<int-websocket:inbound-channel-adapter container="clientWebSocketContainer"
+										   channel="webSocketInputChannel"/>
+
+	<int:logging-channel-adapter id="webSocketInputChannel"/>
+
+</beans>

basic/web-sockets/src/main/resources/static/index.html

@@ -0,0 +1,34 @@
+<!DOCTYPE html>
+<html>
+<head>
+    <title>Time over WebSocket</title>
+    <script src="http://cdn.sockjs.org/sockjs-0.3.min.js"></script>
+    <script type="text/javascript">
+
+        var sock = new SockJS('http://localhost:8080/time');
+        sock.onopen = function () {
+            document.getElementById('time').innerHTML = 'Connecting...';
+        };
+        sock.onmessage = function (e) {
+            document.getElementById('time').innerHTML = e.data;
+        };
+        sock.onclose = function () {
+            document.getElementById('time').innerHTML = "Server closed connection or hasn't been started";
+        };
+    </script>
+</head>
+
+<body style="margin: 0">
+<noscript><h2 style="color: #ff0000">Seems your browser doesn't support Javascript!
+    WebSocket relies on Javascript being enabled. Please enable Javascript and reload this page!</h2></noscript>
+<div id="time"
+     style="position: absolute;
+        bottom: 0;
+        font-size: 800%;
+        height: 200px;
+        margin: auto;
+        text-align: center;
+        top: 0;
+        width: 100%;">Starting...</div>
+</body>
+</html>

basic/web-sockets/src/test/java/org/springframework/integration/samples/websocket/standard/ApplicationTests.java

@@ -0,0 +1,85 @@
+/*
+ * Copyright 2014 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.springframework.integration.samples.websocket.standard;
+
+import static org.hamcrest.Matchers.greaterThanOrEqualTo;
+import static org.hamcrest.Matchers.instanceOf;
+import static org.junit.Assert.assertThat;
+import static org.junit.Assert.assertTrue;
+import static org.junit.Assert.fail;
+
+import java.text.DateFormat;
+import java.text.ParseException;
+import java.util.Date;
+import java.util.concurrent.CountDownLatch;
+import java.util.concurrent.TimeUnit;
+
+import org.junit.Test;
+import org.junit.runner.RunWith;
+
+import org.springframework.boot.test.IntegrationTest;
+import org.springframework.boot.test.SpringApplicationConfiguration;
+import org.springframework.context.ConfigurableApplicationContext;
+import org.springframework.context.support.ClassPathXmlApplicationContext;
+import org.springframework.integration.channel.DirectChannel;
+import org.springframework.integration.samples.websocket.standard.server.Application;
+import org.springframework.messaging.Message;
+import org.springframework.messaging.MessageChannel;
+import org.springframework.messaging.support.ChannelInterceptorAdapter;
+import org.springframework.test.context.junit4.SpringJUnit4ClassRunner;
+import org.springframework.test.context.web.WebAppConfiguration;
+
+/**
+ * @author Artem Bilan
+ * @since 3.0
+ */
+@RunWith(SpringJUnit4ClassRunner.class)
+@SpringApplicationConfiguration(classes = Application.class)
+@WebAppConfiguration
+@IntegrationTest
+public class ApplicationTests {
+
+	@Test
+	public void testWebSockets() throws InterruptedException {
+		ConfigurableApplicationContext ctx = new ClassPathXmlApplicationContext("client-context.xml",
+				org.springframework.integration.samples.websocket.standard.client.Application.class);
+		DirectChannel webSocketInputChannel = ctx.getBean("webSocketInputChannel", DirectChannel.class);
+
+		final CountDownLatch stopLatch = new CountDownLatch(2);
+
+		webSocketInputChannel.addInterceptor(new ChannelInterceptorAdapter() {
+			@Override
+			public void postSend(Message<?> message, MessageChannel channel, boolean sent) {
+				Object payload = message.getPayload();
+				assertThat(payload, instanceOf(String.class));
+				Date date = null;
+				try {
+					date = DateFormat.getDateTimeInstance(DateFormat.LONG, DateFormat.DEFAULT).parse((String) payload);
+				}
+				catch (ParseException e) {
+					fail("fail to parse date");
+				}
+				assertThat(new Date().compareTo(date), greaterThanOrEqualTo(0));
+				stopLatch.countDown();
+			}
+
+		});
+		assertTrue(stopLatch.await(10, TimeUnit.SECONDS));
+		ctx.close();
+	}
+
+}

build.gradle

@@ -139,6 +139,7 @@ subprojects { subproject ->
 
 	repositories {
 		//TODO on release
+//		mavenLocal()
 		maven { url 'http://repo.spring.io/libs-snapshot' }
 		maven { url 'http://repo.spring.io/libs-milestone' }
 //		maven { url 'http://repo.spring.io/libs-staging-local' }
@@ -192,7 +193,7 @@ subprojects { subproject ->
 			subethasmtpVersion = '1.2'
 			slf4jVersion = '1.7.6'
 			springIntegrationVersion = '4.0.4.RELEASE'
-			springIntegration41Version = '4.1.0.M1'
+			springIntegration41Version = '4.1.0.BUILD-SNAPSHOT'
 			springIntegrationDslVersion = '1.0.0.M3'
 			springVersion = '4.0.7.RELEASE'
 			springSecurityVersion = '3.2.4.RELEASE'
@@ -1085,6 +1086,21 @@ project('tx-synch') {
 	}
 }
 
+project('web-sockets') {
+	description = 'Web Sockets Basic Sample'
+
+	apply plugin: 'spring-boot'
+
+	dependencies {
+		compile 'org.springframework.boot:spring-boot-starter-websocket'
+		compile "org.springframework.integration:spring-integration-websocket:$springIntegration41Version"
+
+		testCompile 'org.springframework.boot:spring-boot-starter-test'
+	}
+
+	mainClassName = 'org.springframework.integration.samples.websocket.standard.server.Application'
+}
+
 task wrapper(type: Wrapper) {
 	description = 'Generates gradlew[.bat] scripts'
 	gradleVersion = '1.12'