Map from charset name rather than Charset

With this commit it is no longer assumed that all charset names in the
JsonEncoding can be resolved by Charset.forName. Instead, we store the
charset name itself, rather than the Charset object.

spring-web/src/main/java/org/springframework/http/codec/json/AbstractJackson2Encoder.java

@@ -69,7 +69,7 @@ public abstract class AbstractJackson2Encoder extends Jackson2CodecSupport imple
 
 	private static final Map<MediaType, byte[]> STREAM_SEPARATORS;
 
-	private static final Map<Charset, JsonEncoding> ENCODINGS;
+	private static final Map<String, JsonEncoding> ENCODINGS;
 
 	static {
 		STREAM_SEPARATORS = new HashMap<>(4);
@@ -78,8 +78,7 @@ public abstract class AbstractJackson2Encoder extends Jackson2CodecSupport imple
 
 		ENCODINGS = new HashMap<>(JsonEncoding.values().length);
 		for (JsonEncoding encoding : JsonEncoding.values()) {
-			Charset charset = Charset.forName(encoding.getJavaName());
-			ENCODINGS.put(charset, encoding);
+			ENCODINGS.put(encoding.getJavaName(), encoding);
 		}
 	}
 
@@ -116,7 +115,7 @@ public boolean canEncode(ResolvableType elementType, @Nullable MimeType mimeType
 		}
 		if (mimeType != null && mimeType.getCharset() != null) {
 			Charset charset = mimeType.getCharset();
-			if (!ENCODINGS.containsKey(charset)) {
+			if (!ENCODINGS.containsKey(charset.name())) {
 				return false;
 			}
 		}
@@ -287,7 +286,7 @@ private byte[] streamSeparator(@Nullable MimeType mimeType) {
 	protected JsonEncoding getJsonEncoding(@Nullable MimeType mimeType) {
 		if (mimeType != null && mimeType.getCharset() != null) {
 			Charset charset = mimeType.getCharset();
-			JsonEncoding result = ENCODINGS.get(charset);
+			JsonEncoding result = ENCODINGS.get(charset.name());
 			if (result != null) {
 				return result;
 			}

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

@@ -76,7 +76,7 @@
  */
 public abstract class AbstractJackson2HttpMessageConverter extends AbstractGenericHttpMessageConverter<Object> {
 
-	private static final Map<Charset, JsonEncoding> ENCODINGS = jsonEncodings();
+	private static final Map<String, JsonEncoding> ENCODINGS = jsonEncodings();
 
 	/**
 	 * The default charset used by the converter.
@@ -184,7 +184,7 @@ public boolean canWrite(Class<?> clazz, @Nullable MediaType mediaType) {
 		}
 		if (mediaType != null && mediaType.getCharset() != null) {
 			Charset charset = mediaType.getCharset();
-			if (!ENCODINGS.containsKey(charset)) {
+			if (!ENCODINGS.containsKey(charset.name())) {
 				return false;
 			}
 		}
@@ -247,7 +247,7 @@ private Object readJavaType(JavaType javaType, HttpInputMessage inputMessage) th
 		MediaType contentType = inputMessage.getHeaders().getContentType();
 		Charset charset = getCharset(contentType);
 
-		boolean isUnicode = ENCODINGS.containsKey(charset);
+		boolean isUnicode = ENCODINGS.containsKey(charset.name());
 		try {
 			if (inputMessage instanceof MappingJacksonInputMessage) {
 				Class<?> deserializationView = ((MappingJacksonInputMessage) inputMessage).getDeserializationView();
@@ -374,7 +374,7 @@ protected JavaType getJavaType(Type type, @Nullable Class<?> contextClass) {
 	protected JsonEncoding getJsonEncoding(@Nullable MediaType contentType) {
 		if (contentType != null && contentType.getCharset() != null) {
 			Charset charset = contentType.getCharset();
-			JsonEncoding encoding = ENCODINGS.get(charset);
+			JsonEncoding encoding = ENCODINGS.get(charset.name());
 			if (encoding != null) {
 				return encoding;
 			}
@@ -399,9 +399,9 @@ protected Long getContentLength(Object object, @Nullable MediaType contentType)
 		return super.getContentLength(object, contentType);
 	}
 
-	private static Map<Charset, JsonEncoding> jsonEncodings() {
+	private static Map<String, JsonEncoding> jsonEncodings() {
 		return EnumSet.allOf(JsonEncoding.class).stream()
-				.collect(Collectors.toMap(encoding -> Charset.forName(encoding.getJavaName()), Function.identity()));
+				.collect(Collectors.toMap(JsonEncoding::getJavaName, Function.identity()));
 	}
 
 }