Consistently replace String encoding names with StandardCharset arguments

Closes gh-27664

spring-context/src/main/java/org/springframework/scripting/support/ResourceScriptSource.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2018 the original author or authors.
+ * Copyright 2002-2021 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.
@@ -18,6 +18,7 @@ package org.springframework.scripting.support;
 
 import java.io.IOException;
 import java.io.Reader;
+import java.nio.charset.StandardCharsets;
 
 import org.apache.commons.logging.Log;
 import org.apache.commons.logging.LogFactory;
@@ -72,7 +73,7 @@ public class ResourceScriptSource implements ScriptSource {
 	 */
 	public ResourceScriptSource(Resource resource) {
 		Assert.notNull(resource, "Resource must not be null");
-		this.resource = new EncodedResource(resource, "UTF-8");
+		this.resource = new EncodedResource(resource, StandardCharsets.UTF_8);
 	}
 
 

spring-oxm/src/main/java/org/springframework/oxm/jaxb/Jaxb2Marshaller.java

@@ -32,6 +32,7 @@ import java.net.URI;
 import java.net.URISyntaxException;
 import java.net.URLDecoder;
 import java.net.URLEncoder;
+import java.nio.charset.StandardCharsets;
 import java.util.Arrays;
 import java.util.Calendar;
 import java.util.Date;
@@ -972,12 +973,7 @@ public class Jaxb2Marshaller implements MimeMarshaller, MimeUnmarshaller, Generi
 			String host = getHost(elementNamespace, dataHandler);
 			String contentId = UUID.randomUUID() + "@" + host;
 			this.mimeContainer.addAttachment("<" + contentId + ">", dataHandler);
-			try {
-				contentId = URLEncoder.encode(contentId, "UTF-8");
-			}
-			catch (UnsupportedEncodingException ex) {
-				// ignore
-			}
+			contentId = URLEncoder.encode(contentId, StandardCharsets.UTF_8);
 			return CID + contentId;
 		}