Switch writeAcceptCharset to false by default

Closes gh-22506

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

@@ -117,11 +117,8 @@ public class FormHttpMessageConverter implements HttpMessageConverter<MultiValue
 		this.supportedMediaTypes.add(MediaType.APPLICATION_FORM_URLENCODED);
 		this.supportedMediaTypes.add(MediaType.MULTIPART_FORM_DATA);
 
-		StringHttpMessageConverter stringHttpMessageConverter = new StringHttpMessageConverter();
-		stringHttpMessageConverter.setWriteAcceptCharset(false);  // see SPR-7316
-
 		this.partConverters.add(new ByteArrayHttpMessageConverter());
-		this.partConverters.add(stringHttpMessageConverter);
+		this.partConverters.add(new StringHttpMessageConverter());
 		this.partConverters.add(new ResourceHttpMessageConverter());
 
 		applyDefaultCharset();

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

@@ -81,8 +81,7 @@ public class ObjectToStringHttpMessageConverter extends AbstractHttpMessageConve
 
 
 	/**
-	 * Indicates whether the {@code Accept-Charset} should be written to any outgoing request.
-	 * <p>Default is {@code true}.
+	 * Delegates to {@link StringHttpMessageConverter#setWriteAcceptCharset(boolean)}.
 	 */
 	public void setWriteAcceptCharset(boolean writeAcceptCharset) {
 		this.stringHttpMessageConverter.setWriteAcceptCharset(writeAcceptCharset);

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

@@ -52,7 +52,7 @@ public class StringHttpMessageConverter extends AbstractHttpMessageConverter<Str
 	@Nullable
 	private volatile List<Charset> availableCharsets;
 
-	private boolean writeAcceptCharset = true;
+	private boolean writeAcceptCharset = false;
 
 
 	/**
@@ -76,7 +76,7 @@ public class StringHttpMessageConverter extends AbstractHttpMessageConverter<Str
 	 * Whether the {@code Accept-Charset} header should be written to any outgoing
 	 * request sourced from the value of {@link Charset#availableCharsets()}.
 	 * The behavior is suppressed if the header has already been set.
-	 * <p>Default is {@code true}.
+	 * <p>As of 5.2, by default is set to {@code false}.
 	 */
 	public void setWriteAcceptCharset(boolean writeAcceptCharset) {
 		this.writeAcceptCharset = writeAcceptCharset;

spring-web/src/test/java/org/springframework/http/converter/ObjectToStringHttpMessageConverterTests.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2018 the original author or authors.
+ * Copyright 2002-2019 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.
@@ -107,6 +107,7 @@ public class ObjectToStringHttpMessageConverterTests {
 
 	@Test
 	public void writeAcceptCharset() throws IOException {
+		this.converter.setWriteAcceptCharset(true);
 		this.converter.write(new Date(), null, this.response);
 
 		assertNotNull(this.servletResponse.getHeader("Accept-Charset"));

spring-web/src/test/java/org/springframework/http/converter/StringHttpMessageConverterTests.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2016 the original author or authors.
+ * Copyright 2002-2019 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.
@@ -79,7 +79,7 @@ public class StringHttpMessageConverterTests {
 		assertEquals(body, this.outputMessage.getBodyAsString(StandardCharsets.ISO_8859_1));
 		assertEquals(new MediaType("text", "plain", StandardCharsets.ISO_8859_1), headers.getContentType());
 		assertEquals(body.getBytes(StandardCharsets.ISO_8859_1).length, headers.getContentLength());
-		assertFalse(headers.getAcceptCharset().isEmpty());
+		assertTrue(headers.getAcceptCharset().isEmpty());
 	}
 
 	@Test
@@ -91,7 +91,7 @@ public class StringHttpMessageConverterTests {
 		assertEquals(body, this.outputMessage.getBodyAsString(StandardCharsets.UTF_8));
 		assertEquals(TEXT_PLAIN_UTF_8, headers.getContentType());
 		assertEquals(body.getBytes(StandardCharsets.UTF_8).length, headers.getContentLength());
-		assertFalse(headers.getAcceptCharset().isEmpty());
+		assertTrue(headers.getAcceptCharset().isEmpty());
 	}
 
 	@Test  // SPR-8867
@@ -106,7 +106,7 @@ public class StringHttpMessageConverterTests {
 		assertEquals(body, this.outputMessage.getBodyAsString(StandardCharsets.UTF_8));
 		assertEquals(TEXT_PLAIN_UTF_8, headers.getContentType());
 		assertEquals(body.getBytes(StandardCharsets.UTF_8).length, headers.getContentLength());
-		assertFalse(headers.getAcceptCharset().isEmpty());
+		assertTrue(headers.getAcceptCharset().isEmpty());
 	}
 
 }

spring-webmvc/src/main/java/org/springframework/web/servlet/config/annotation/WebMvcConfigurationSupport.java

@@ -831,11 +831,8 @@ public class WebMvcConfigurationSupport implements ApplicationContextAware, Serv
 	 * @param messageConverters the list to add the default message converters to
 	 */
 	protected final void addDefaultHttpMessageConverters(List<HttpMessageConverter<?>> messageConverters) {
-		StringHttpMessageConverter stringHttpMessageConverter = new StringHttpMessageConverter();
-		stringHttpMessageConverter.setWriteAcceptCharset(false);  // see SPR-7316
-
 		messageConverters.add(new ByteArrayHttpMessageConverter());
-		messageConverters.add(stringHttpMessageConverter);
+		messageConverters.add(new StringHttpMessageConverter());
 		messageConverters.add(new ResourceHttpMessageConverter());
 		messageConverters.add(new ResourceRegionHttpMessageConverter());
 		try {

spring-webmvc/src/main/java/org/springframework/web/servlet/function/support/RouterFunctionMapping.java

@@ -149,12 +149,8 @@ public class RouterFunctionMapping extends AbstractHandlerMapping implements Ini
 	 */
 	private void initMessageConverters() {
 		List<HttpMessageConverter<?>> messageConverters = new ArrayList<>(4);
-
 		messageConverters.add(new ByteArrayHttpMessageConverter());
-
-		StringHttpMessageConverter stringHttpMessageConverter = new StringHttpMessageConverter();
-		stringHttpMessageConverter.setWriteAcceptCharset(false);  // see SPR-7316
-		messageConverters.add(stringHttpMessageConverter);
+		messageConverters.add(new StringHttpMessageConverter());
 
 		try {
 			messageConverters.add(new SourceHttpMessageConverter<>());

spring-webmvc/src/main/java/org/springframework/web/servlet/mvc/method/annotation/ExceptionHandlerExceptionResolver.java

@@ -105,12 +105,9 @@ public class ExceptionHandlerExceptionResolver extends AbstractHandlerMethodExce
 
 
 	public ExceptionHandlerExceptionResolver() {
-		StringHttpMessageConverter stringHttpMessageConverter = new StringHttpMessageConverter();
-		stringHttpMessageConverter.setWriteAcceptCharset(false);  // see SPR-7316
-
 		this.messageConverters = new ArrayList<>();
 		this.messageConverters.add(new ByteArrayHttpMessageConverter());
-		this.messageConverters.add(stringHttpMessageConverter);
+		this.messageConverters.add(new StringHttpMessageConverter());
 		try {
 			this.messageConverters.add(new SourceHttpMessageConverter<>());
 		}

spring-webmvc/src/main/java/org/springframework/web/servlet/mvc/method/annotation/RequestMappingHandlerAdapter.java

@@ -193,12 +193,9 @@ public class RequestMappingHandlerAdapter extends AbstractHandlerMethodAdapter
 
 
 	public RequestMappingHandlerAdapter() {
-		StringHttpMessageConverter stringHttpMessageConverter = new StringHttpMessageConverter();
-		stringHttpMessageConverter.setWriteAcceptCharset(false);  // see SPR-7316
-
 		this.messageConverters = new ArrayList<>(4);
 		this.messageConverters.add(new ByteArrayHttpMessageConverter());
-		this.messageConverters.add(stringHttpMessageConverter);
+		this.messageConverters.add(new StringHttpMessageConverter());
 		try {
 			this.messageConverters.add(new SourceHttpMessageConverter<>());
 		}