Add livereload auto-configuration

Add auto-configuration to start and trigger livereload.

Closes gh-3085

spring-boot-developer-tools/src/main/java/org/springframework/boot/developertools/autoconfigure/DeveloperToolsProperties.java

@@ -31,10 +31,16 @@ public class DeveloperToolsProperties {
 
 	private Restart restart = new Restart();
 
+	private Livereload livereload = new Livereload();
+
 	public Restart getRestart() {
 		return this.restart;
 	}
 
+	public Livereload getLivereload() {
+		return this.livereload;
+	}
+
 	/**
 	 * Restart properties
 	 */
@@ -68,4 +74,37 @@ public class DeveloperToolsProperties {
 
 	}
 
+	/**
+	 * LiveReload properties
+	 */
+	public static class Livereload {
+
+		/**
+		 * Enable a livereload.com compatible server.
+		 */
+		private boolean enabled = true;
+
+		/**
+		 * Server port.
+		 */
+		private int port = 35729;
+
+		public boolean isEnabled() {
+			return this.enabled;
+		}
+
+		public void setEnabled(boolean enabled) {
+			this.enabled = enabled;
+		}
+
+		public int getPort() {
+			return this.port;
+		}
+
+		public void setPort(int port) {
+			this.port = port;
+		}
+
+	}
+
 }

spring-boot-developer-tools/src/main/java/org/springframework/boot/developertools/autoconfigure/LocalDeveloperToolsAutoConfiguration.java

@@ -27,10 +27,13 @@ import org.springframework.boot.developertools.classpath.ClassPathChangedEvent;
 import org.springframework.boot.developertools.classpath.ClassPathFileSystemWatcher;
 import org.springframework.boot.developertools.classpath.ClassPathRestartStrategy;
 import org.springframework.boot.developertools.classpath.PatternClassPathRestartStrategy;
+import org.springframework.boot.developertools.livereload.LiveReloadServer;
 import org.springframework.boot.developertools.restart.ConditionalOnInitializedRestarter;
+import org.springframework.boot.developertools.restart.RestartScope;
 import org.springframework.boot.developertools.restart.Restarter;
 import org.springframework.context.annotation.Bean;
 import org.springframework.context.annotation.Configuration;
+import org.springframework.context.event.ContextRefreshedEvent;
 import org.springframework.context.event.EventListener;
 
 /**
@@ -52,6 +55,45 @@ public class LocalDeveloperToolsAutoConfiguration {
 		return new LocalDeveloperPropertyDefaultsPostProcessor();
 	}
 
+	/**
+	 * Local LiveReload configuration.
+	 */
+	@ConditionalOnProperty(prefix = "spring.developertools.livereload", name = "enabled", matchIfMissing = true)
+	static class LiveReloadConfiguration {
+
+		@Autowired
+		private DeveloperToolsProperties properties;
+
+		@Autowired(required = false)
+		private LiveReloadServer liveReloadServer;
+
+		@Bean
+		@RestartScope
+		@ConditionalOnMissingBean
+		public LiveReloadServer liveReloadServer() {
+			return new LiveReloadServer(this.properties.getLivereload().getPort(),
+					Restarter.getInstance().getThreadFactory());
+		}
+
+		@EventListener
+		public void onContextRefreshed(ContextRefreshedEvent event) {
+			optionalLiveReloadServer().triggerReload();
+		}
+
+		@EventListener
+		public void onClassPathChanged(ClassPathChangedEvent event) {
+			if (!event.isRestartRequired()) {
+				optionalLiveReloadServer().triggerReload();
+			}
+		}
+
+		@Bean
+		public OptionalLiveReloadServer optionalLiveReloadServer() {
+			return new OptionalLiveReloadServer(this.liveReloadServer);
+		}
+
+	}
+
 	/**
 	 * Local Restart Configuration.
 	 */

spring-boot-developer-tools/src/main/java/org/springframework/boot/developertools/autoconfigure/OptionalLiveReloadServer.java

@@ -0,0 +1,77 @@
+/*
+ * Copyright 2012-2015 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.boot.developertools.autoconfigure;
+
+import javax.annotation.PostConstruct;
+
+import org.apache.commons.logging.Log;
+import org.apache.commons.logging.LogFactory;
+import org.springframework.boot.developertools.livereload.LiveReloadServer;
+
+/**
+ * Manages an optional {@link LiveReloadServer}. The {@link LiveReloadServer} may
+ * gracefully fail to start (e.g. because of a port conflict) or may be omitted entirely.
+ *
+ * @author Phillip Webb
+ * @since 1.3.0
+ */
+public class OptionalLiveReloadServer {
+
+	private static final Log logger = LogFactory.getLog(OptionalLiveReloadServer.class);
+
+	private LiveReloadServer server;
+
+	/**
+	 * Create a new {@link OptionalLiveReloadServer} instance.
+	 * @param server the server to manage or {@code null}
+	 */
+	public OptionalLiveReloadServer(LiveReloadServer server) {
+		this.server = server;
+	}
+
+	/**
+	 * {@link PostConstruct} method to start the server if possible.
+	 * @throws Exception
+	 */
+	@PostConstruct
+	public void startServer() throws Exception {
+		if (this.server != null) {
+			try {
+				if (!this.server.isStarted()) {
+					this.server.start();
+				}
+				logger.info("LiveReload server is running on port "
+						+ this.server.getPort());
+			}
+			catch (Exception ex) {
+				logger.warn("Unable to start LiveReload server");
+				logger.debug("Live reload start error", ex);
+				this.server = null;
+			}
+		}
+	}
+
+	/**
+	 * Trigger LiveReload if the server is up an running.
+	 */
+	public void triggerReload() {
+		if (this.server != null) {
+			this.server.triggerReload();
+		}
+	}
+
+}