Simplify project structure

- harmonize module and directory names
- optimize Gradle settings
- remove unused Grails sample

Resolves: #1447

spring-session-samples/spring-session-sample-boot-websocket/src/main/java/sample/websocket/WebSocketConnectHandler.java

@@ -0,0 +1,57 @@
+/*
+ * Copyright 2014-2016 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
+ *
+ *      https://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 sample.websocket;
+
+import java.security.Principal;
+import java.util.Arrays;
+import java.util.Calendar;
+
+import sample.data.ActiveWebSocketUser;
+import sample.data.ActiveWebSocketUserRepository;
+
+import org.springframework.context.ApplicationListener;
+import org.springframework.messaging.MessageHeaders;
+import org.springframework.messaging.simp.SimpMessageHeaderAccessor;
+import org.springframework.messaging.simp.SimpMessageSendingOperations;
+import org.springframework.web.socket.messaging.SessionConnectEvent;
+
+public class WebSocketConnectHandler<S>
+		implements ApplicationListener<SessionConnectEvent> {
+	private ActiveWebSocketUserRepository repository;
+	private SimpMessageSendingOperations messagingTemplate;
+
+	public WebSocketConnectHandler(SimpMessageSendingOperations messagingTemplate,
+			ActiveWebSocketUserRepository repository) {
+		super();
+		this.messagingTemplate = messagingTemplate;
+		this.repository = repository;
+	}
+
+	@Override
+	public void onApplicationEvent(SessionConnectEvent event) {
+		MessageHeaders headers = event.getMessage().getHeaders();
+		Principal user = SimpMessageHeaderAccessor.getUser(headers);
+		if (user == null) {
+			return;
+		}
+		String id = SimpMessageHeaderAccessor.getSessionId(headers);
+		this.repository.save(
+				new ActiveWebSocketUser(id, user.getName(), Calendar.getInstance()));
+		this.messagingTemplate.convertAndSend("/topic/friends/signin",
+				Arrays.asList(user.getName()));
+	}
+}

spring-session-samples/spring-session-sample-boot-websocket/src/main/java/sample/websocket/WebSocketDisconnectHandler.java

@@ -0,0 +1,51 @@
+/*
+ * Copyright 2014-2018 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
+ *
+ *      https://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 sample.websocket;
+
+import java.util.Arrays;
+
+import sample.data.ActiveWebSocketUserRepository;
+
+import org.springframework.context.ApplicationListener;
+import org.springframework.messaging.simp.SimpMessageSendingOperations;
+import org.springframework.web.socket.messaging.SessionDisconnectEvent;
+
+public class WebSocketDisconnectHandler<S>
+		implements ApplicationListener<SessionDisconnectEvent> {
+	private ActiveWebSocketUserRepository repository;
+	private SimpMessageSendingOperations messagingTemplate;
+
+	public WebSocketDisconnectHandler(SimpMessageSendingOperations messagingTemplate,
+			ActiveWebSocketUserRepository repository) {
+		super();
+		this.messagingTemplate = messagingTemplate;
+		this.repository = repository;
+	}
+
+	@Override
+	public void onApplicationEvent(SessionDisconnectEvent event) {
+		String id = event.getSessionId();
+		if (id == null) {
+			return;
+		}
+		this.repository.findById(id).ifPresent((user) -> {
+			this.repository.deleteById(id);
+			this.messagingTemplate.convertAndSend("/topic/friends/signout",
+					Arrays.asList(user.getUsername()));
+		});
+	}
+}