Reduce access on headers for STOMP messaging

Issue: SPR-16165

spring-messaging/src/main/java/org/springframework/messaging/simp/SimpMessageHeaderAccessor.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.
@@ -205,16 +205,20 @@ public String getDetailedLogMessage(Object payload) {
 
 	private StringBuilder getBaseLogMessage() {
 		StringBuilder sb = new StringBuilder();
-		sb.append(getMessageType().name());
-		if (getDestination() != null) {
-			sb.append(" destination=").append(getDestination());
+		SimpMessageType messageType = getMessageType();
+		sb.append(messageType != null ? messageType.name() : SimpMessageType.OTHER);
+		String destination = getDestination();
+		if (destination != null) {
+			sb.append(" destination=").append(destination);
 		}
-		if (getSubscriptionId() != null) {
-			sb.append(" subscriptionId=").append(getSubscriptionId());
+		String subscriptionId = getSubscriptionId();
+		if (subscriptionId != null) {
+			sb.append(" subscriptionId=").append(subscriptionId);
 		}
 		sb.append(" session=").append(getSessionId());
-		if (getUser() != null) {
-			sb.append(" user=").append(getUser().getName());
+		Principal user = getUser();
+		if (user != null) {
+			sb.append(" user=").append(user.getName());
 		}
 		return sb;
 	}

spring-messaging/src/main/java/org/springframework/messaging/simp/stomp/StompDecoder.java

@@ -138,9 +138,12 @@ private Message<byte[]> decodeMessage(ByteBuffer buffer, MultiValueMap<String, S
 				payload = readPayload(buffer, headerAccessor);
 			}
 			if (payload != null) {
-				if (payload.length > 0 && !headerAccessor.getCommand().isBodyAllowed()) {
-					throw new StompConversionException(headerAccessor.getCommand() +
-							" shouldn't have a payload: length=" + payload.length + ", headers=" + headers);
+				if (payload.length > 0) {
+					StompCommand stompCommand = headerAccessor.getCommand();
+					if (stompCommand != null && !stompCommand.isBodyAllowed()) {
+						throw new StompConversionException(stompCommand +
+								" shouldn't have a payload: length=" + payload.length + ", headers=" + headers);
+					}
 				}
 				headerAccessor.updateSimpMessageHeadersFromStompHeaders();
 				headerAccessor.setLeaveMutable(true);

spring-messaging/src/main/java/org/springframework/messaging/simp/stomp/StompHeaderAccessor.java

@@ -17,6 +17,7 @@
 package org.springframework.messaging.simp.stomp;
 
 import java.nio.charset.Charset;
+import java.security.Principal;
 import java.util.Arrays;
 import java.util.Collections;
 import java.util.List;
@@ -163,11 +164,13 @@ else if (StompCommand.CONNECT.equals(command)) {
 	}
 
 	void updateStompHeadersFromSimpMessageHeaders() {
-		if (getDestination() != null) {
-			setNativeHeader(STOMP_DESTINATION_HEADER, getDestination());
+		String destination = getDestination();
+		if (destination != null) {
+			setNativeHeader(STOMP_DESTINATION_HEADER, destination);
 		}
-		if (getContentType() != null) {
-			setNativeHeader(STOMP_CONTENT_TYPE_HEADER, getContentType().toString());
+		MimeType contentType = getContentType();
+		if (contentType != null) {
+			setNativeHeader(STOMP_CONTENT_TYPE_HEADER, contentType.toString());
 		}
 		trySetStompHeaderForSubscriptionId();
 	}
@@ -185,21 +188,24 @@ Map<String, List<String>> getNativeHeaders() {
 	}
 
 	public StompCommand updateStompCommandAsClientMessage() {
-		if (getMessageType() != SimpMessageType.MESSAGE) {
-			throw new IllegalStateException("Unexpected message type " + getMessageType());
+		SimpMessageType messageType = getMessageType();
+		if (messageType != SimpMessageType.MESSAGE) {
+			throw new IllegalStateException("Unexpected message type " + messageType);
 		}
-		if (getCommand() == null) {
+		StompCommand command = getCommand();
+		if (command == null) {
 			setHeader(COMMAND_HEADER, StompCommand.SEND);
 		}
-		else if (!getCommand().equals(StompCommand.SEND)) {
-			throw new IllegalStateException("Unexpected STOMP command " + getCommand());
+		else if (!command.equals(StompCommand.SEND)) {
+			throw new IllegalStateException("Unexpected STOMP command " + command);
 		}
-		return getCommand();
+		return command;
 	}
 
 	public void updateStompCommandAsServerMessage() {
-		if (getMessageType() != SimpMessageType.MESSAGE) {
-			throw new IllegalStateException("Unexpected message type " + getMessageType());
+		SimpMessageType messageType = getMessageType();
+		if (messageType != SimpMessageType.MESSAGE) {
+			throw new IllegalStateException("Unexpected message type " + messageType);
 		}
 		StompCommand command = getCommand();
 		if ((command == null) || StompCommand.SEND.equals(command)) {
@@ -273,7 +279,8 @@ public void setSubscriptionId(String subscriptionId) {
 	private void trySetStompHeaderForSubscriptionId() {
 		String subscriptionId = getSubscriptionId();
 		if (subscriptionId != null) {
-			if (getCommand() != null && StompCommand.MESSAGE.equals(getCommand())) {
+			StompCommand command = getCommand();
+			if (command != null && StompCommand.MESSAGE.equals(command)) {
 				setNativeHeader(STOMP_SUBSCRIPTION_HEADER, subscriptionId);
 			}
 			else {
@@ -286,10 +293,8 @@ private void trySetStompHeaderForSubscriptionId() {
 	}
 
 	public Integer getContentLength() {
-		if (containsNativeHeader(STOMP_CONTENT_LENGTH_HEADER)) {
-			return Integer.valueOf(getFirstNativeHeader(STOMP_CONTENT_LENGTH_HEADER));
-		}
-		return null;
+		String header = getFirstNativeHeader(STOMP_CONTENT_LENGTH_HEADER);
+		return (header != null ? Integer.valueOf(header) : null);
 	}
 
 	public void setContentLength(int contentLength) {
@@ -390,23 +395,26 @@ public void setVersion(String version) {
 
 	@Override
 	public String getShortLogMessage(Object payload) {
-		if (StompCommand.SUBSCRIBE.equals(getCommand())) {
+		StompCommand command = getCommand();
+		if (StompCommand.SUBSCRIBE.equals(command)) {
 			return "SUBSCRIBE " + getDestination() + " id=" + getSubscriptionId() + appendSession();
 		}
-		else if (StompCommand.UNSUBSCRIBE.equals(getCommand())) {
+		else if (StompCommand.UNSUBSCRIBE.equals(command)) {
 			return "UNSUBSCRIBE id=" + getSubscriptionId() + appendSession();
 		}
-		else if (StompCommand.SEND.equals(getCommand())) {
+		else if (StompCommand.SEND.equals(command)) {
 			return "SEND " + getDestination() + appendSession() + appendPayload(payload);
 		}
-		else if (StompCommand.CONNECT.equals(getCommand())) {
-			return "CONNECT" + (getUser() != null ? " user=" + getUser().getName() : "") + appendSession();
+		else if (StompCommand.CONNECT.equals(command)) {
+			Principal user = getUser();
+			return "CONNECT" + (user != null ? " user=" + user.getName() : "") + appendSession();
 		}
-		else if (StompCommand.CONNECTED.equals(getCommand())) {
+		else if (StompCommand.CONNECTED.equals(command)) {
 			return "CONNECTED heart-beat=" + Arrays.toString(getHeartbeat()) + appendSession();
 		}
-		else if (StompCommand.DISCONNECT.equals(getCommand())) {
-			return "DISCONNECT" + (getReceipt() != null ? " receipt=" + getReceipt() : "") + appendSession();
+		else if (StompCommand.DISCONNECT.equals(command)) {
+			String receipt = getReceipt();
+			return "DISCONNECT" + (receipt != null ? " receipt=" + receipt : "") + appendSession();
 		}
 		else {
 			return getDetailedLogMessage(payload);
@@ -444,11 +452,12 @@ private String appendPayload(Object payload) {
 					"Expected byte array payload but got: " + ClassUtils.getQualifiedName(payload.getClass()));
 		}
 		byte[] bytes = (byte[]) payload;
-		String contentType = (getContentType() != null ? " " + getContentType().toString() : "");
-		if (bytes.length == 0 || getContentType() == null || !isReadableContentType()) {
+		MimeType mimeType = getContentType();
+		String contentType = (mimeType != null ? " " + mimeType.toString() : "");
+		if (bytes.length == 0 || mimeType == null || !isReadableContentType()) {
 			return contentType;
 		}
-		Charset charset = getContentType().getCharset();
+		Charset charset = mimeType.getCharset();
 		charset = (charset != null ? charset : StompDecoder.UTF8_CHARSET);
 		return (bytes.length < 80) ?
 				contentType + " payload=" + new String(bytes, charset) :

spring-messaging/src/main/java/org/springframework/messaging/support/MessageHeaderAccessor.java

@@ -535,8 +535,9 @@ else if (payload instanceof byte[]) {
 	}
 
 	protected boolean isReadableContentType() {
+		MimeType contentType = getContentType();
 		for (MimeType mimeType : READABLE_MIME_TYPES) {
-			if (mimeType.includes(getContentType())) {
+			if (mimeType.includes(contentType)) {
 				return true;
 			}
 		}
@@ -557,6 +558,8 @@ public String toString() {
 	 * its type does not match the required type.
 	 * <p>This is for cases where the existence of an accessor is strongly expected
 	 * (followed up with an assertion) or where an accessor will be created otherwise.
+	 * @param message the message to get an accessor for
+	 * @param requiredType the required accessor type (or {@code null} for any)
 	 * @return an accessor instance of the specified type, or {@code null} if none
 	 * @since 4.1
 	 */
@@ -568,6 +571,8 @@ public static <T extends MessageHeaderAccessor> T getAccessor(Message<?> message
 	 * A variation of {@link #getAccessor(org.springframework.messaging.Message, Class)}
 	 * with a {@code MessageHeaders} instance instead of a {@code Message}.
 	 * <p>This is for cases when a full message may not have been created yet.
+	 * @param messageHeaders the message headers to get an accessor for
+	 * @param requiredType the required accessor type (or {@code null} for any)
 	 * @return an accessor instance of the specified type, or {@code null} if none
 	 * @since 4.1
 	 */

spring-websocket/src/main/java/org/springframework/web/socket/messaging/StompSubProtocolHandler.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.
@@ -285,11 +285,12 @@ else if (webSocketMessage instanceof BinaryMessage) {
 					logger.trace("From client: " + headerAccessor.getShortLogMessage(message.getPayload()));
 				}
 
-				boolean isConnect = StompCommand.CONNECT.equals(headerAccessor.getCommand());
+				StompCommand command = headerAccessor.getCommand();
+				boolean isConnect = StompCommand.CONNECT.equals(command);
 				if (isConnect) {
 					this.stats.incrementConnectCount();
 				}
-				else if (StompCommand.DISCONNECT.equals(headerAccessor.getCommand())) {
+				else if (StompCommand.DISCONNECT.equals(command)) {
 					this.stats.incrementDisconnectCount();
 				}
 
@@ -308,10 +309,10 @@ else if (StompCommand.DISCONNECT.equals(headerAccessor.getCommand())) {
 							if (isConnect) {
 								publishEvent(new SessionConnectEvent(this, message, getUser(session)));
 							}
-							else if (StompCommand.SUBSCRIBE.equals(headerAccessor.getCommand())) {
+							else if (StompCommand.SUBSCRIBE.equals(command)) {
 								publishEvent(new SessionSubscribeEvent(this, message, getUser(session)));
 							}
-							else if (StompCommand.UNSUBSCRIBE.equals(headerAccessor.getCommand())) {
+							else if (StompCommand.UNSUBSCRIBE.equals(command)) {
 								publishEvent(new SessionUnsubscribeEvent(this, message, getUser(session)));
 							}
 						}