Polish contribution

See gh-24785

spring-context-indexer/src/main/java/org/springframework/context/index/processor/SortedProperties.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2019 the original author or authors.
+ * Copyright 2002-2020 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-core/src/main/java/org/springframework/core/SortedProperties.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2019 the original author or authors.
+ * Copyright 2002-2020 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-messaging/src/main/java/org/springframework/messaging/converter/ProtobufMessageConverter.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2019 the original author or authors.
+ * Copyright 2002-2020 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/RestTemplateXhrTransport.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2019 the original author or authors.
+ * Copyright 2002-2020 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.
@@ -253,7 +253,7 @@ public class RestTemplateXhrTransport extends AbstractXhrTransport {
 		}
 
 		private void handleFrame(ByteArrayOutputStream os) throws IOException {
-			String content = os.toString(SockJsFrame.CHARSET.toString());
+			String content = os.toString(SockJsFrame.CHARSET.name());
 			os.reset();
 			if (logger.isTraceEnabled()) {
 				logger.trace("XHR receive content: " + content);