Reduce access on headers for STOMP messaging

Issue: SPR-16165

spring-messaging/src/main/java/org/springframework/messaging/simp/SimpMessageHeaderAccessor.java

@@ -215,15 +215,18 @@ public class SimpMessageHeaderAccessor extends NativeMessageHeaderAccessor {
 		StringBuilder sb = new StringBuilder();
 		SimpMessageType messageType = getMessageType();
 		sb.append(messageType != null ? messageType.name() : SimpMessageType.OTHER);
-		if (getDestination() != null) {
-			sb.append(" destination=").append(getDestination());
+		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

@@ -150,7 +150,7 @@ public class StompDecoder {
 				if (payload.length > 0) {
 					StompCommand stompCommand = headerAccessor.getCommand();
 					if (stompCommand != null && !stompCommand.isBodyAllowed()) {
-						throw new StompConversionException(headerAccessor.getCommand() +
+						throw new StompConversionException(stompCommand +
 								" shouldn't have a payload: length=" + payload.length + ", headers=" + headers);
 					}
 				}

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

@@ -18,6 +18,7 @@ package org.springframework.messaging.simp.stomp;
 
 import java.nio.charset.Charset;
 import java.nio.charset.StandardCharsets;
+import java.security.Principal;
 import java.util.Arrays;
 import java.util.Collections;
 import java.util.List;
@@ -165,11 +166,13 @@ public class StompHeaderAccessor extends SimpMessageHeaderAccessor {
 	}
 
 	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();
 	}
@@ -188,21 +191,24 @@ public class StompHeaderAccessor extends SimpMessageHeaderAccessor {
 	}
 
 	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)) {
@@ -278,7 +284,8 @@ public class StompHeaderAccessor extends SimpMessageHeaderAccessor {
 	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 {
@@ -403,23 +410,26 @@ public class StompHeaderAccessor extends SimpMessageHeaderAccessor {
 
 	@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);
@@ -462,11 +472,12 @@ public class StompHeaderAccessor extends SimpMessageHeaderAccessor {
 					"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 : StandardCharsets.UTF_8);
 		return (bytes.length < 80) ?
 				contentType + " payload=" + new String(bytes, charset) :

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

@@ -546,8 +546,9 @@ public class MessageHeaderAccessor {
 	}
 
 	protected boolean isReadableContentType() {
+		MimeType contentType = getContentType();
 		for (MimeType mimeType : READABLE_MIME_TYPES) {
-			if (mimeType.includes(getContentType())) {
+			if (mimeType.includes(contentType)) {
 				return true;
 			}
 		}

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

@@ -268,11 +268,12 @@ public class StompSubProtocolHandler implements SubProtocolHandler, ApplicationE
 					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();
 				}
 
@@ -292,10 +293,10 @@ public class StompSubProtocolHandler implements SubProtocolHandler, ApplicationE
 							if (isConnect) {
 								publishEvent(this.eventPublisher, new SessionConnectEvent(this, message, user));
 							}
-							else if (StompCommand.SUBSCRIBE.equals(headerAccessor.getCommand())) {
+							else if (StompCommand.SUBSCRIBE.equals(command)) {
 								publishEvent(this.eventPublisher, new SessionSubscribeEvent(this, message, user));
 							}
-							else if (StompCommand.UNSUBSCRIBE.equals(headerAccessor.getCommand())) {
+							else if (StompCommand.UNSUBSCRIBE.equals(command)) {
 								publishEvent(this.eventPublisher, new SessionUnsubscribeEvent(this, message, user));
 							}
 						}