GH-1352: Fix Possible NPEs

Author: garyrussell

spring-rabbit-stream/src/main/java/org/springframework/rabbit/stream/listener/StreamListenerContainer.java

@@ -104,6 +104,7 @@ public StreamMessageConverter getMessageConverter() {
 	 * @param messageConverter the converter.
 	 */
 	public void setMessageConverter(StreamMessageConverter messageConverter) {
+		Assert.notNull(messageConverter, "'messageConverter' cannot be null");
 		this.messageConverter = messageConverter;
 	}
 

spring-rabbit-stream/src/main/java/org/springframework/rabbit/stream/support/converter/DefaultStreamMessageConverter.java

@@ -143,20 +143,23 @@ private void toMessageProperties(com.rabbitmq.stream.Message streamMessage,
 			StreamMessageProperties mProps) {
 
 		Properties properties = streamMessage.getProperties();
-		JavaUtils.INSTANCE
-				.acceptIfNotNull(properties.getMessageIdAsString(), mProps::setMessageId)
-				.acceptIfNotNull(properties.getUserId(), usr -> mProps.setUserId(new String(usr, this.charset)))
-				.acceptIfNotNull(properties.getTo(), mProps::setTo)
-				.acceptIfNotNull(properties.getSubject(), mProps::setSubject)
-				.acceptIfNotNull(properties.getReplyTo(), mProps::setReplyTo)
-				.acceptIfNotNull(properties.getCorrelationIdAsString(), mProps::setCorrelationId)
-				.acceptIfNotNull(properties.getContentType(), mProps::setContentType)
-				.acceptIfNotNull(properties.getContentEncoding(), mProps::setContentEncoding)
-				.acceptIfNotNull(properties.getAbsoluteExpiryTime(), exp -> mProps.setExpiration(Long.toString(exp)))
-				.acceptIfNotNull(properties.getCreationTime(), mProps::setCreationTime)
-				.acceptIfNotNull(properties.getGroupId(), mProps::setGroupId)
-				.acceptIfNotNull(properties.getGroupSequence(), mProps::setGroupSequence)
-				.acceptIfNotNull(properties.getReplyToGroupId(), mProps::setReplyToGroupId);
+		if (properties != null) {
+			JavaUtils.INSTANCE
+					.acceptIfNotNull(properties.getMessageIdAsString(), mProps::setMessageId)
+					.acceptIfNotNull(properties.getUserId(), usr -> mProps.setUserId(new String(usr, this.charset)))
+					.acceptIfNotNull(properties.getTo(), mProps::setTo)
+					.acceptIfNotNull(properties.getSubject(), mProps::setSubject)
+					.acceptIfNotNull(properties.getReplyTo(), mProps::setReplyTo)
+					.acceptIfNotNull(properties.getCorrelationIdAsString(), mProps::setCorrelationId)
+					.acceptIfNotNull(properties.getContentType(), mProps::setContentType)
+					.acceptIfNotNull(properties.getContentEncoding(), mProps::setContentEncoding)
+					.acceptIfNotNull(properties.getAbsoluteExpiryTime(),
+							exp -> mProps.setExpiration(Long.toString(exp)))
+					.acceptIfNotNull(properties.getCreationTime(), mProps::setCreationTime)
+					.acceptIfNotNull(properties.getGroupId(), mProps::setGroupId)
+					.acceptIfNotNull(properties.getGroupSequence(), mProps::setGroupSequence)
+					.acceptIfNotNull(properties.getReplyToGroupId(), mProps::setReplyToGroupId);
+		}
 		Map<String, Object> applicationProperties = streamMessage.getApplicationProperties();
 		if (applicationProperties != null) {
 			mProps.getHeaders().putAll(applicationProperties);