Deprecate MediaType.APPLICATION_JSON_UTF8

This commit deprecates MediaType.APPLICATION_JSON_UTF8 and
MediaType.APPLICATION_PROBLEM_JSON_UTF8 in favor of
MediaType.APPLICATION_JSON and MediaType.APPLICATION_PROBLEM_JSON since
UTF-8 encoding is now handled correctly by most browsers
(related bug has been fixed in Chrome since September 2017).

MediaType.APPLICATION_JSON is now used as the default JSON content type.

Closes gh-22788

spring-web/src/test/java/org/springframework/http/codec/json/Jackson2JsonDecoderTests.java

@@ -72,7 +72,6 @@ public class Jackson2JsonDecoderTests extends AbstractDecoderTestCase<Jackson2Js
 	@Test
 	public void canDecode() {
 		assertTrue(decoder.canDecode(forClass(Pojo.class), APPLICATION_JSON));
-		assertTrue(decoder.canDecode(forClass(Pojo.class), APPLICATION_JSON_UTF8));
 		assertTrue(decoder.canDecode(forClass(Pojo.class), APPLICATION_STREAM_JSON));
 		assertTrue(decoder.canDecode(forClass(Pojo.class), null));
 

spring-web/src/test/java/org/springframework/http/codec/json/Jackson2JsonEncoderTests.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.
@@ -44,7 +44,6 @@ import org.springframework.util.MimeTypeUtils;
 import static java.util.Collections.singletonMap;
 import static org.junit.Assert.*;
 import static org.springframework.http.MediaType.APPLICATION_JSON;
-import static org.springframework.http.MediaType.APPLICATION_JSON_UTF8;
 import static org.springframework.http.MediaType.APPLICATION_OCTET_STREAM;
 import static org.springframework.http.MediaType.APPLICATION_STREAM_JSON;
 import static org.springframework.http.MediaType.APPLICATION_XML;
@@ -67,7 +66,6 @@ public class Jackson2JsonEncoderTests extends AbstractEncoderTestCase<Jackson2Js
 	public void canEncode() {
 		ResolvableType pojoType = ResolvableType.forClass(Pojo.class);
 		assertTrue(this.encoder.canEncode(pojoType, APPLICATION_JSON));
-		assertTrue(this.encoder.canEncode(pojoType, APPLICATION_JSON_UTF8));
 		assertTrue(this.encoder.canEncode(pojoType, APPLICATION_STREAM_JSON));
 		assertTrue(this.encoder.canEncode(pojoType, null));
 

spring-web/src/test/java/org/springframework/http/codec/multipart/MultipartHttpMessageWriterTests.java

@@ -102,7 +102,7 @@ public class MultipartHttpMessageWriterTests extends AbstractLeakCheckingTestCas
 		bodyBuilder.part("name 2", "value 2+2");
 		bodyBuilder.part("logo", logo);
 		bodyBuilder.part("utf8", utf8);
-		bodyBuilder.part("json", new Foo("bar"), MediaType.APPLICATION_JSON_UTF8);
+		bodyBuilder.part("json", new Foo("bar"), MediaType.APPLICATION_JSON);
 		bodyBuilder.asyncPart("publisher", publisher, String.class);
 		Mono<MultiValueMap<String, HttpEntity<?>>> result = Mono.just(bodyBuilder.build());
 
@@ -144,7 +144,7 @@ public class MultipartHttpMessageWriterTests extends AbstractLeakCheckingTestCas
 
 		part = requestParts.getFirst("json");
 		assertEquals("json", part.name());
-		assertEquals(MediaType.APPLICATION_JSON_UTF8, part.headers().getContentType());
+		assertEquals(MediaType.APPLICATION_JSON, part.headers().getContentType());
 
 		String value = StringDecoder.textPlainOnly(false).decodeToMono(part.content(),
 				ResolvableType.forClass(String.class), MediaType.TEXT_PLAIN,

spring-web/src/test/java/org/springframework/http/converter/json/MappingJackson2HttpMessageConverterTests.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.
@@ -139,7 +139,7 @@ public class MappingJackson2HttpMessageConverterTests {
 		assertTrue(result.contains("\"array\":[\"Foo\",\"Bar\"]"));
 		assertTrue(result.contains("\"bool\":true"));
 		assertTrue(result.contains("\"bytes\":\"AQI=\""));
-		assertEquals("Invalid content-type", new MediaType("application", "json", StandardCharsets.UTF_8),
+		assertEquals("Invalid content-type", MediaType.APPLICATION_JSON,
 				outputMessage.getHeaders().getContentType());
 	}
 
@@ -161,7 +161,7 @@ public class MappingJackson2HttpMessageConverterTests {
 		assertTrue(result.contains("\"array\":[\"Foo\",\"Bar\"]"));
 		assertTrue(result.contains("\"bool\":true"));
 		assertTrue(result.contains("\"bytes\":\"AQI=\""));
-		assertEquals("Invalid content-type", new MediaType("application", "json", StandardCharsets.UTF_8),
+		assertEquals("Invalid content-type", MediaType.APPLICATION_JSON,
 				outputMessage.getHeaders().getContentType());
 	}
 

spring-web/src/test/java/org/springframework/http/converter/protobuf/ProtobufHttpMessageConverterTests.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.
@@ -143,7 +143,7 @@ public class ProtobufHttpMessageConverterTests {
 				new ProtobufHttpMessageConverter.ProtobufJavaUtilSupport(null, null),
 				this.extensionRegistry);
 		MockHttpOutputMessage outputMessage = new MockHttpOutputMessage();
-		MediaType contentType = MediaType.APPLICATION_JSON_UTF8;
+		MediaType contentType = MediaType.APPLICATION_JSON;
 		this.converter.write(this.testMsg, contentType, outputMessage);
 
 		assertEquals(contentType, outputMessage.getHeaders().getContentType());

spring-web/src/test/java/org/springframework/http/converter/smile/MappingJackson2SmileHttpMessageConverterTests.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.
@@ -17,7 +17,6 @@
 package org.springframework.http.converter.smile;
 
 import java.io.IOException;
-import java.nio.charset.StandardCharsets;
 
 import com.fasterxml.jackson.databind.ObjectMapper;
 import com.fasterxml.jackson.dataformat.smile.SmileFactory;
@@ -90,7 +89,7 @@ public class MappingJackson2SmileHttpMessageConverterTests {
 		body.setBytes(new byte[]{0x1, 0x2});
 		converter.write(body, null, outputMessage);
 		assertArrayEquals(mapper.writeValueAsBytes(body), outputMessage.getBodyAsBytes());
-		assertEquals("Invalid content-type", new MediaType("application", "x-jackson-smile", StandardCharsets.UTF_8),
+		assertEquals("Invalid content-type", new MediaType("application", "x-jackson-smile"),
 				outputMessage.getHeaders().getContentType());
 	}