Configure JSON and XML converters on HttpMessageConverters

This commit ensures that XML and JSON converters on both client and
server are configured using the dedicated methods on
`HttpMessageConverters`, instead of pushing them ahead of default
converters.

Closes gh-47917
Fixes gh-48096

Author: bclozel

module/spring-boot-http-converter/src/main/java/org/springframework/boot/http/converter/autoconfigure/DefaultClientHttpMessageConvertersCustomizer.java

@@ -54,14 +54,26 @@ public void customize(ClientBuilder builder) {
 				else if (converter instanceof KotlinSerializationJsonHttpMessageConverter) {
 					builder.withKotlinSerializationJsonConverter(converter);
 				}
-				else if (converter.getSupportedMediaTypes().contains(MediaType.APPLICATION_JSON)) {
+				else if (supportsMediaType(converter, MediaType.APPLICATION_JSON)) {
 					builder.withJsonConverter(converter);
 				}
+				else if (supportsMediaType(converter, MediaType.APPLICATION_XML)) {
+					builder.withXmlConverter(converter);
+				}
 				else {
 					builder.addCustomConverter(converter);
 				}
 			});
 		}
 	}
 
+	private static boolean supportsMediaType(HttpMessageConverter<?> converter, MediaType mediaType) {
+		for (MediaType supportedMediaType : converter.getSupportedMediaTypes()) {
+			if (supportedMediaType.equalsTypeAndSubtype(mediaType)) {
+				return true;
+			}
+		}
+		return false;
+	}
+
 }

module/spring-boot-http-converter/src/main/java/org/springframework/boot/http/converter/autoconfigure/DefaultServerHttpMessageConvertersCustomizer.java

@@ -52,16 +52,28 @@ public void customize(ServerBuilder builder) {
 					builder.withStringConverter(converter);
 				}
 				else if (converter instanceof KotlinSerializationJsonHttpMessageConverter) {
-					builder.addCustomConverter(converter);
+					builder.withKotlinSerializationJsonConverter(converter);
 				}
-				else if (converter.getSupportedMediaTypes().contains(MediaType.APPLICATION_JSON)) {
+				else if (supportsMediaType(converter, MediaType.APPLICATION_JSON)) {
 					builder.withJsonConverter(converter);
 				}
+				else if (supportsMediaType(converter, MediaType.APPLICATION_XML)) {
+					builder.withXmlConverter(converter);
+				}
 				else {
 					builder.addCustomConverter(converter);
 				}
 			});
 		}
 	}
 
+	private static boolean supportsMediaType(HttpMessageConverter<?> converter, MediaType mediaType) {
+		for (MediaType supportedMediaType : converter.getSupportedMediaTypes()) {
+			if (supportedMediaType.equalsTypeAndSubtype(mediaType)) {
+				return true;
+			}
+		}
+		return false;
+	}
+
 }

module/spring-boot-http-converter/src/test/java/org/springframework/boot/http/converter/autoconfigure/HttpMessageConvertersAutoConfigurationTests.java

@@ -418,13 +418,17 @@ private void assertConverterBeanRegisteredWithHttpMessageConverters(AssertableAp
 			.getBean(ClientHttpMessageConvertersCustomizer.class);
 		ClientBuilder clientBuilder = HttpMessageConverters.forClient().registerDefaults();
 		clientCustomizer.customize(clientBuilder);
-		assertThat(clientBuilder.build()).contains(converter);
+		HttpMessageConverters clientConverters = clientBuilder.build();
+		assertThat(clientConverters).contains(converter);
+		assertThat(clientConverters).filteredOn((c) -> type.isAssignableFrom(c.getClass())).hasSize(1);
 
 		ServerHttpMessageConvertersCustomizer serverCustomizer = context
 			.getBean(ServerHttpMessageConvertersCustomizer.class);
 		ServerBuilder serverBuilder = HttpMessageConverters.forServer().registerDefaults();
 		serverCustomizer.customize(serverBuilder);
-		assertThat(serverBuilder.build()).contains(converter);
+		HttpMessageConverters serverConverters = serverBuilder.build();
+		assertThat(serverConverters).contains(converter);
+		assertThat(serverConverters).filteredOn((c) -> type.isAssignableFrom(c.getClass())).hasSize(1);
 	}
 
 	private void assertConvertersBeanRegisteredWithHttpMessageConverters(AssertableApplicationContext context,