Consistent support for new JsonMappingException wording in Jackson 2.9

Issue: SPR-16947

spring-messaging/src/main/java/org/springframework/messaging/converter/MappingJackson2MessageConverter.java

@@ -54,7 +54,7 @@ import org.springframework.util.MimeType;
  * <li>{@link DeserializationFeature#FAIL_ON_UNKNOWN_PROPERTIES} is disabled</li>
  * </ul>
  *
- * <p>Compatible with Jackson 2.6 and higher, as of Spring 4.3.
+ * <p>Compatible with Jackson 2.9 and higher, as of Spring 5.1.
  *
  * @author Rossen Stoyanchev
  * @author Juergen Hoeller
@@ -181,8 +181,8 @@ public class MappingJackson2MessageConverter extends AbstractMessageConverter {
 			return;
 		}
 
-		boolean debugLevel = (cause instanceof JsonMappingException &&
-				cause.getMessage().startsWith("Can not find"));
+		// Do not log warning for serializer not found (note: different message wording on Jackson 2.9)
+		boolean debugLevel = (cause instanceof JsonMappingException && cause.getMessage().startsWith("Cannot find"));
 
 		if (debugLevel ? logger.isDebugEnabled() : logger.isWarnEnabled()) {
 			String msg = "Failed to evaluate Jackson " + (type instanceof JavaType ? "de" : "") +

spring-web/src/main/java/org/springframework/http/converter/json/AbstractJackson2HttpMessageConverter.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2017 the original author or authors.
+ * Copyright 2002-2018 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.
@@ -65,6 +65,7 @@ import org.springframework.util.TypeUtils;
  * @author Juergen Hoeller
  * @author Sebastien Deleuze
  * @since 4.1
+ * @see MappingJackson2HttpMessageConverter
  */
 public abstract class AbstractJackson2HttpMessageConverter extends AbstractGenericHttpMessageConverter<Object> {
 
@@ -189,8 +190,8 @@ public abstract class AbstractJackson2HttpMessageConverter extends AbstractGener
 			return;
 		}
 
-		boolean debugLevel = (cause instanceof JsonMappingException &&
-				(cause.getMessage().startsWith("Can not find") || cause.getMessage().startsWith("Cannot find")));
+		// Do not log warning for serializer not found (note: different message wording on Jackson 2.9)
+		boolean debugLevel = (cause instanceof JsonMappingException && cause.getMessage().startsWith("Cannot find"));
 
 		if (debugLevel ? logger.isDebugEnabled() : logger.isWarnEnabled()) {
 			String msg = "Failed to evaluate Jackson " + (type instanceof JavaType ? "de" : "") +