Backport selected refinements from the nullability efforts

Issue: SPR-15656

spring-websocket/src/main/java/org/springframework/web/socket/adapter/NativeWebSocketSession.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2013 the original author or authors.
+ * Copyright 2002-2017 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.
@@ -28,15 +28,15 @@ import org.springframework.web.socket.WebSocketSession;
 public interface NativeWebSocketSession extends WebSocketSession {
 
 	/**
-	 * Return the underlying native WebSocketSession, if available.
-	 * @return the native session or {@code null}
+	 * Return the underlying native WebSocketSession.
 	 */
 	Object getNativeSession();
 
 	/**
 	 * Return the underlying native WebSocketSession, if available.
 	 * @param requiredType the required type of the session
-	 * @return the native session of the required type or {@code null}
+	 * @return the native session of the required type,
+	 * or {@code null} if not available
 	 */
 	<T> T getNativeSession(Class<T> requiredType);
 

spring-websocket/src/main/java/org/springframework/web/socket/client/WebSocketConnectionManager.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2014 the original author or authors.
+ * Copyright 2002-2017 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.
@@ -89,7 +89,7 @@ public class WebSocketConnectionManager extends ConnectionManagerSupport {
 	}
 
 	/**
-	 * @return the configured origin.
+	 * Return the configured origin.
 	 */
 	public String getOrigin() {
 		return this.headers.getOrigin();
@@ -151,7 +151,9 @@ public class WebSocketConnectionManager extends ConnectionManagerSupport {
 
 	@Override
 	protected void closeConnection() throws Exception {
-		this.webSocketSession.close();
+		if (this.webSocketSession != null) {
+			this.webSocketSession.close();
+		}
 	}
 
 	@Override

spring-websocket/src/main/java/org/springframework/web/socket/client/jetty/JettyWebSocketClient.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2014 the original author or authors.
+ * Copyright 2002-2017 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.
@@ -84,9 +84,8 @@ public class JettyWebSocketClient extends AbstractWebSocketClient implements Lif
 
 	/**
 	 * Set an {@link AsyncListenableTaskExecutor} to use when opening connections.
-	 * If this property is set to {@code null}, calls to  any of the
+	 * If this property is set to {@code null}, calls to any of the
 	 * {@code doHandshake} methods will block until the connection is established.
-	 *
 	 * <p>By default an instance of {@code SimpleAsyncTaskExecutor} is used.
 	 */
 	public void setTaskExecutor(AsyncListenableTaskExecutor taskExecutor) {

spring-websocket/src/main/java/org/springframework/web/socket/config/WebSocketMessageBrokerStats.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2015 the original author or authors.
+ * Copyright 2002-2017 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.
@@ -106,11 +106,11 @@ public class WebSocketMessageBrokerStats {
 	}
 
 	private ScheduledFuture<?> initLoggingTask(long initialDelay) {
-		if (logger.isInfoEnabled() && this.loggingPeriod > 0) {
+		if (this.loggingPeriod > 0 && logger.isInfoEnabled()) {
 			return this.sockJsTaskScheduler.scheduleAtFixedRate(new Runnable() {
 				@Override
 				public void run() {
-					logger.info(WebSocketMessageBrokerStats.this.toString());
+					logger.info(WebSocketMessageBrokerStats.this);
 				}
 			}, initialDelay, this.loggingPeriod, TimeUnit.MILLISECONDS);
 		}

spring-websocket/src/main/java/org/springframework/web/socket/config/annotation/SockJsServiceRegistration.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2014 the original author or authors.
+ * Copyright 2002-2017 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.
@@ -31,9 +31,9 @@ import org.springframework.web.socket.sockjs.transport.TransportHandlingSockJsSe
 import org.springframework.web.socket.sockjs.transport.handler.DefaultSockJsService;
 
 /**
- * A helper class for configuring SockJS fallback options, typically used indirectly, in
- * conjunction with {@link org.springframework.web.socket.config.annotation.EnableWebSocket @EnableWebSocket} and
- * {@link WebSocketConfigurer}.
+ * A helper class for configuring SockJS fallback options for use with an
+ * {@link org.springframework.web.socket.config.annotation.EnableWebSocket} and
+ * {@link WebSocketConfigurer} setup.
  *
  * @author Rossen Stoyanchev
  * @since 4.0
@@ -264,12 +264,11 @@ public class SockJsServiceRegistration {
 		if (this.webSocketEnabled != null) {
 			service.setWebSocketEnabled(this.webSocketEnabled);
 		}
-		if (this.allowedOrigins != null) {
-			service.setAllowedOrigins(this.allowedOrigins);
-		}
 		if (this.suppressCors != null) {
 			service.setSuppressCors(this.suppressCors);
 		}
+		service.setAllowedOrigins(this.allowedOrigins);
+
 		if (this.messageCodec != null) {
 			service.setMessageCodec(this.messageCodec);
 		}

spring-websocket/src/main/java/org/springframework/web/socket/config/annotation/WebMvcStompWebSocketEndpointRegistration.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2015 the original author or authors.
+ * Copyright 2002-2017 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.
@@ -16,7 +16,9 @@
 
 package org.springframework.web.socket.config.annotation;
 
+import java.util.ArrayList;
 import java.util.Arrays;
+import java.util.List;
 
 import org.springframework.scheduling.TaskScheduler;
 import org.springframework.util.Assert;
@@ -32,13 +34,11 @@ import org.springframework.web.socket.server.support.WebSocketHttpRequestHandler
 import org.springframework.web.socket.sockjs.SockJsService;
 import org.springframework.web.socket.sockjs.support.SockJsHttpRequestHandler;
 import org.springframework.web.socket.sockjs.transport.handler.WebSocketTransportHandler;
-
-import java.util.ArrayList;
-import java.util.List;
 /**
  * An abstract base class for configuring STOMP over WebSocket/SockJS endpoints.
  *
  * @author Rossen Stoyanchev
+ * @author Juergen Hoeller
  * @since 4.0
  */
 public class WebMvcStompWebSocketEndpointRegistration implements StompWebSocketEndpointRegistration {
@@ -55,7 +55,7 @@ public class WebMvcStompWebSocketEndpointRegistration implements StompWebSocketE
 
 	private final List<String> allowedOrigins = new ArrayList<String>();
 
-	private StompSockJsServiceRegistration registration;
+	private SockJsServiceRegistration registration;
 
 
 	public WebMvcStompWebSocketEndpointRegistration(String[] paths, WebSocketHandler webSocketHandler,
@@ -69,6 +69,7 @@ public class WebMvcStompWebSocketEndpointRegistration implements StompWebSocketE
 		this.sockJsTaskScheduler = sockJsTaskScheduler;
 	}
 
+
 	@Override
 	public StompWebSocketEndpointRegistration setHandshakeHandler(HandshakeHandler handshakeHandler) {
 		Assert.notNull(handshakeHandler, "'handshakeHandler' must not be null");
@@ -95,14 +96,14 @@ public class WebMvcStompWebSocketEndpointRegistration implements StompWebSocketE
 
 	@Override
 	public SockJsServiceRegistration withSockJS() {
-		this.registration = new StompSockJsServiceRegistration(this.sockJsTaskScheduler);
+		this.registration = new SockJsServiceRegistration(this.sockJsTaskScheduler);
 		HandshakeInterceptor[] interceptors = getInterceptors();
 		if (interceptors.length > 0) {
 			this.registration.setInterceptors(interceptors);
 		}
 		if (this.handshakeHandler != null) {
-			WebSocketTransportHandler transportHandler = new WebSocketTransportHandler(this.handshakeHandler);
-			this.registration.setTransportHandlerOverrides(transportHandler);
+			WebSocketTransportHandler handler = new WebSocketTransportHandler(this.handshakeHandler);
+			this.registration.setTransportHandlerOverrides(handler);
 		}
 		if (!this.allowedOrigins.isEmpty()) {
 			this.registration.setAllowedOrigins(this.allowedOrigins.toArray(new String[this.allowedOrigins.size()]));
@@ -146,16 +147,4 @@ public class WebMvcStompWebSocketEndpointRegistration implements StompWebSocketE
 		return mappings;
 	}
 
-
-	private static class StompSockJsServiceRegistration extends SockJsServiceRegistration {
-
-		public StompSockJsServiceRegistration(TaskScheduler defaultTaskScheduler) {
-			super(defaultTaskScheduler);
-		}
-
-		protected SockJsService getSockJsService() {
-			return super.getSockJsService();
-		}
-	}
-
 }

spring-websocket/src/main/java/org/springframework/web/socket/config/annotation/WebSocketMessageBrokerConfigurationSupport.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2015 the original author or authors.
+ * Copyright 2002-2017 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.
@@ -134,7 +134,7 @@ public abstract class WebSocketMessageBrokerConfigurationSupport extends Abstrac
 		MappingJackson2MessageConverter messageConverter = super.createJacksonConverter();
 		// Use Jackson builder in order to have JSR-310 and Joda-Time modules registered automatically
 		messageConverter.setObjectMapper(Jackson2ObjectMapperBuilder.json()
-				.applicationContext(this.getApplicationContext()).build());
+				.applicationContext(getApplicationContext()).build());
 		return messageConverter;
 	}
 

spring-websocket/src/main/java/org/springframework/web/socket/messaging/SessionSubscribeEvent.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2014 the original author or authors.
+ * Copyright 2002-2017 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.
@@ -16,7 +16,6 @@
 
 package org.springframework.web.socket.messaging;
 
-
 import java.security.Principal;
 
 import org.springframework.messaging.Message;
@@ -31,7 +30,6 @@ import org.springframework.messaging.Message;
 @SuppressWarnings("serial")
 public class SessionSubscribeEvent extends AbstractSubProtocolEvent {
 
-
 	public SessionSubscribeEvent(Object source, Message<byte[]> message) {
 		super(source, message);
 	}

spring-websocket/src/main/java/org/springframework/web/socket/messaging/SessionUnsubscribeEvent.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2014 the original author or authors.
+ * Copyright 2002-2017 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.
@@ -16,7 +16,6 @@
 
 package org.springframework.web.socket.messaging;
 
-
 import java.security.Principal;
 
 import org.springframework.messaging.Message;
@@ -31,7 +30,6 @@ import org.springframework.messaging.Message;
 @SuppressWarnings("serial")
 public class SessionUnsubscribeEvent extends AbstractSubProtocolEvent {
 
-
 	public SessionUnsubscribeEvent(Object source, Message<byte[]> message) {
 		super(source, message);
 	}

spring-websocket/src/main/java/org/springframework/web/socket/messaging/WebSocketAnnotationMethodMessageHandler.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2015 the original author or authors.
+ * Copyright 2002-2017 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.
@@ -19,6 +19,7 @@ package org.springframework.web.socket.messaging;
 import java.util.ArrayList;
 import java.util.List;
 
+import org.springframework.context.ApplicationContext;
 import org.springframework.core.annotation.AnnotationAwareOrderComparator;
 import org.springframework.messaging.MessageChannel;
 import org.springframework.messaging.SubscribableChannel;
@@ -28,7 +29,6 @@ import org.springframework.messaging.simp.SimpMessageSendingOperations;
 import org.springframework.messaging.simp.annotation.support.SimpAnnotationMethodMessageHandler;
 import org.springframework.web.method.ControllerAdviceBean;
 
-
 /**
  * A sub-class of {@link SimpAnnotationMethodMessageHandler} to provide support
  * for {@link org.springframework.web.bind.annotation.ControllerAdvice
@@ -39,7 +39,6 @@ import org.springframework.web.method.ControllerAdviceBean;
  */
 public class WebSocketAnnotationMethodMessageHandler extends SimpAnnotationMethodMessageHandler {
 
-
 	public WebSocketAnnotationMethodMessageHandler(SubscribableChannel clientInChannel,
 			MessageChannel clientOutChannel, SimpMessageSendingOperations brokerTemplate) {
 
@@ -54,13 +53,14 @@ public class WebSocketAnnotationMethodMessageHandler extends SimpAnnotationMetho
 	}
 
 	private void initControllerAdviceCache() {
-		if (getApplicationContext() == null) {
+		ApplicationContext context = getApplicationContext();
+		if (context == null) {
 			return;
 		}
 		if (logger.isDebugEnabled()) {
-			logger.debug("Looking for @MessageExceptionHandler mappings: " + getApplicationContext());
+			logger.debug("Looking for @MessageExceptionHandler mappings: " + context);
 		}
-		List<ControllerAdviceBean> beans = ControllerAdviceBean.findAnnotatedBeans(getApplicationContext());
+		List<ControllerAdviceBean> beans = ControllerAdviceBean.findAnnotatedBeans(context);
 		AnnotationAwareOrderComparator.sort(beans);
 		initMessagingAdviceCache(MessagingControllerAdviceBean.createFromList(beans));
 	}

spring-websocket/src/main/java/org/springframework/web/socket/server/standard/ServletServerContainerFactoryBean.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2016 the original author or authors.
+ * Copyright 2002-2017 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.
@@ -63,7 +63,7 @@ public class ServletServerContainerFactoryBean
 		this.asyncSendTimeout = timeoutInMillis;
 	}
 
-	public long getAsyncSendTimeout() {
+	public Long getAsyncSendTimeout() {
 		return this.asyncSendTimeout;
 	}
 

spring-websocket/src/main/java/org/springframework/web/socket/sockjs/client/AbstractClientSockJsSession.java

@@ -309,15 +309,19 @@ public abstract class AbstractClientSockJsSession implements WebSocketSession {
 	}
 
 	public void afterTransportClosed(CloseStatus closeStatus) {
-		this.closeStatus = (this.closeStatus != null ? this.closeStatus : closeStatus);
-		Assert.state(this.closeStatus != null, "CloseStatus not available");
+		CloseStatus cs = this.closeStatus;
+		if (cs == null) {
+			cs = closeStatus;
+			this.closeStatus = closeStatus;
+		}
+		Assert.state(cs != null, "CloseStatus not available");
 		if (logger.isDebugEnabled()) {
-			logger.debug("Transport closed with " + this.closeStatus + " in " + this);
+			logger.debug("Transport closed with " + cs + " in " + this);
 		}
 
 		this.state = State.CLOSED;
 		try {
-			this.webSocketHandler.afterConnectionClosed(this, this.closeStatus);
+			this.webSocketHandler.afterConnectionClosed(this, cs);
 		}
 		catch (Throwable ex) {
 			logger.error("WebSocketHandler.afterConnectionClosed threw an exception", ex);

spring-websocket/src/main/java/org/springframework/web/socket/sockjs/client/DefaultTransportRequest.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2015 the original author or authors.
+ * Copyright 2002-2017 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.

spring-websocket/src/main/java/org/springframework/web/socket/sockjs/client/WebSocketClientSockJsSession.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2014 the original author or authors.
+ * Copyright 2002-2017 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.
@@ -16,7 +16,6 @@
 
 package org.springframework.web.socket.sockjs.client;
 
-
 import java.io.IOException;
 import java.net.InetSocketAddress;
 import java.util.List;
@@ -57,12 +56,7 @@ public class WebSocketClientSockJsSession extends AbstractClientSockJsSession im
 	@SuppressWarnings("unchecked")
 	@Override
 	public <T> T getNativeSession(Class<T> requiredType) {
-		if (requiredType != null) {
-			if (requiredType.isInstance(this.webSocketSession)) {
-				return (T) this.webSocketSession;
-			}
-		}
-		return null;
+		return (requiredType == null || requiredType.isInstance(this.webSocketSession) ? (T) this.webSocketSession : null);
 	}
 
 	@Override

spring-websocket/src/main/java/org/springframework/web/socket/sockjs/transport/session/AbstractSockJsSession.java

@@ -121,8 +121,8 @@ public abstract class AbstractSockJsSession implements SockJsSession {
 	public AbstractSockJsSession(String id, SockJsServiceConfig config, WebSocketHandler handler,
 			Map<String, Object> attributes) {
 
-		Assert.notNull(id, "SessionId must not be null");
-		Assert.notNull(config, "SockJsConfig must not be null");
+		Assert.notNull(id, "Session id must not be null");
+		Assert.notNull(config, "SockJsServiceConfig must not be null");
 		Assert.notNull(handler, "WebSocketHandler must not be null");
 
 		this.id = id;

spring-websocket/src/main/java/org/springframework/web/socket/sockjs/transport/session/WebSocketServerSockJsSession.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2016 the original author or authors.
+ * Copyright 2002-2017 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.
@@ -140,7 +140,7 @@ public class WebSocketServerSockJsSession extends AbstractSockJsSession implemen
 	@Override
 	public Object getNativeSession() {
 		return (this.webSocketSession instanceof NativeWebSocketSession ?
-				((NativeWebSocketSession) this.webSocketSession).getNativeSession() : null);
+				((NativeWebSocketSession) this.webSocketSession).getNativeSession() : this.webSocketSession);
 	}
 
 	@Override
@@ -190,7 +190,9 @@ public class WebSocketServerSockJsSession extends AbstractSockJsSession implemen
 			tryCloseWithSockJsTransportError(ex, CloseStatus.BAD_DATA);
 			return;
 		}
-		delegateMessages(messages);
+		if (messages != null) {
+			delegateMessages(messages);
+		}
 	}
 
 	@Override
@@ -226,7 +228,9 @@ public class WebSocketServerSockJsSession extends AbstractSockJsSession implemen
 			synchronized (this.disconnectLock) {
 				if (isActive()) {
 					this.disconnected = true;
-					this.webSocketSession.close(status);
+					if (this.webSocketSession != null) {
+						this.webSocketSession.close(status);
+					}
 				}
 			}
 		}