Deprecate framework-specific @*Endpoint annotations

Prior to this commit, applications could declare Actuator Endpoints
using web framework-specific annotations, such as `@ServletEndpoint`,
@ControllerEndpoint and @RestControllerEndpoint.

Such annotations are closely tied to the programming model of specific
web technologies, such as Servlet or Spring MVC. Unlike other
`@Endpoint` support, they are not portable and will not work
transparently over blocking/reactive and transports.

Because of the strong adherence of this support with the underlying
infrastructure, it makes it impossible to evolve the implementation of
Actuator support without breaking this use case. The reference
documentation has been advocating for using `@Endpoint` and
`@*Operation` for custom endpoints for a long time now.

This commit deprecates this specific support in favor of the recommended
approach.

Closes gh-31768

Author: bclozel

spring-boot-project/spring-boot-actuator-autoconfigure/src/main/java/org/springframework/boot/actuate/autoconfigure/cloudfoundry/servlet/CloudFoundryActuatorAutoConfiguration.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2012-2023 the original author or authors.
+ * Copyright 2012-2024 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.
@@ -111,6 +111,7 @@ public CloudFoundryInfoEndpointWebExtension cloudFoundryInfoEndpointWebExtension
 	}
 
 	@Bean
+	@SuppressWarnings("removal")
 	public CloudFoundryWebEndpointServletHandlerMapping cloudFoundryWebEndpointServletHandlerMapping(
 			ParameterValueMapper parameterMapper, EndpointMediaTypes endpointMediaTypes,
 			RestTemplateBuilder restTemplateBuilder, ServletEndpointsSupplier servletEndpointsSupplier,

spring-boot-project/spring-boot-actuator-autoconfigure/src/main/java/org/springframework/boot/actuate/autoconfigure/endpoint/web/ServletEndpointManagementContextConfiguration.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2012-2022 the original author or authors.
+ * Copyright 2012-2024 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.
@@ -47,6 +47,7 @@
 public class ServletEndpointManagementContextConfiguration {
 
 	@Bean
+	@SuppressWarnings("removal")
 	public IncludeExcludeEndpointFilter<ExposableServletEndpoint> servletExposeExcludePropertyEndpointFilter(
 			WebEndpointProperties properties) {
 		WebEndpointProperties.Exposure exposure = properties.getExposure();
@@ -56,6 +57,7 @@ public IncludeExcludeEndpointFilter<ExposableServletEndpoint> servletExposeExclu
 
 	@Configuration(proxyBeanMethods = false)
 	@ConditionalOnClass(DispatcherServlet.class)
+	@SuppressWarnings("removal")
 	public static class WebMvcServletEndpointManagementContextConfiguration {
 
 		@Bean
@@ -70,6 +72,7 @@ public ServletEndpointRegistrar servletEndpointRegistrar(WebEndpointProperties p
 	@Configuration(proxyBeanMethods = false)
 	@ConditionalOnClass(ResourceConfig.class)
 	@ConditionalOnMissingClass("org.springframework.web.servlet.DispatcherServlet")
+	@SuppressWarnings("removal")
 	public static class JerseyServletEndpointManagementContextConfiguration {
 
 		@Bean

spring-boot-project/spring-boot-actuator-autoconfigure/src/main/java/org/springframework/boot/actuate/autoconfigure/endpoint/web/WebEndpointAutoConfiguration.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2012-2022 the original author or authors.
+ * Copyright 2012-2024 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.
@@ -96,6 +96,7 @@ public WebEndpointDiscoverer webEndpointDiscoverer(ParameterValueMapper paramete
 
 	@Bean
 	@ConditionalOnMissingBean(ControllerEndpointsSupplier.class)
+	@SuppressWarnings("removal")
 	public ControllerEndpointDiscoverer controllerEndpointDiscoverer(ObjectProvider<PathMapper> endpointPathMappers,
 			ObjectProvider<Collection<EndpointFilter<ExposableControllerEndpoint>>> filters) {
 		return new ControllerEndpointDiscoverer(this.applicationContext, endpointPathMappers.orderedStream().toList(),
@@ -124,6 +125,7 @@ public IncludeExcludeEndpointFilter<ExposableControllerEndpoint> controllerExpos
 
 	@Configuration(proxyBeanMethods = false)
 	@ConditionalOnWebApplication(type = Type.SERVLET)
+	@SuppressWarnings("removal")
 	static class WebEndpointServletConfiguration {
 
 		@Bean

spring-boot-project/spring-boot-actuator-autoconfigure/src/main/java/org/springframework/boot/actuate/autoconfigure/endpoint/web/jersey/JerseyWebEndpointManagementContextConfiguration.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2012-2023 the original author or authors.
+ * Copyright 2012-2024 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.
@@ -84,6 +84,7 @@ class JerseyWebEndpointManagementContextConfiguration {
 	private static final EndpointId HEALTH_ENDPOINT_ID = EndpointId.of("health");
 
 	@Bean
+	@SuppressWarnings("removal")
 	JerseyWebEndpointsResourcesRegistrar jerseyWebEndpointsResourcesRegistrar(Environment environment,
 			WebEndpointsSupplier webEndpointsSupplier, ServletEndpointsSupplier servletEndpointsSupplier,
 			EndpointMediaTypes endpointMediaTypes, WebEndpointProperties webEndpointProperties) {
@@ -124,6 +125,7 @@ private boolean shouldRegisterLinksMapping(WebEndpointProperties properties, Env
 	/**
 	 * Register endpoints with the {@link ResourceConfig} for the management context.
 	 */
+	@SuppressWarnings("removal")
 	static class JerseyWebEndpointsResourcesRegistrar implements ManagementContextResourceConfigCustomizer {
 
 		private final WebEndpointsSupplier webEndpointsSupplier;

spring-boot-project/spring-boot-actuator-autoconfigure/src/main/java/org/springframework/boot/actuate/autoconfigure/endpoint/web/servlet/WebMvcEndpointManagementContextConfiguration.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2012-2023 the original author or authors.
+ * Copyright 2012-2024 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.
@@ -82,6 +82,7 @@ public class WebMvcEndpointManagementContextConfiguration {
 
 	@Bean
 	@ConditionalOnMissingBean
+	@SuppressWarnings("removal")
 	public WebMvcEndpointHandlerMapping webEndpointServletHandlerMapping(WebEndpointsSupplier webEndpointsSupplier,
 			ServletEndpointsSupplier servletEndpointsSupplier, ControllerEndpointsSupplier controllerEndpointsSupplier,
 			EndpointMediaTypes endpointMediaTypes, CorsEndpointProperties corsProperties,

spring-boot-project/spring-boot-actuator-autoconfigure/src/test/java/org/springframework/boot/actuate/autoconfigure/endpoint/web/ServletEndpointManagementContextConfigurationTests.java

@@ -42,6 +42,7 @@
  * @author Phillip Webb
  * @author Madhura Bhave
  */
+@SuppressWarnings("removal")
 class ServletEndpointManagementContextConfigurationTests {
 
 	private final WebApplicationContextRunner contextRunner = new WebApplicationContextRunner()

spring-boot-project/spring-boot-actuator-autoconfigure/src/test/java/org/springframework/boot/actuate/autoconfigure/endpoint/web/WebEndpointAutoConfigurationTests.java

@@ -95,6 +95,7 @@ void webApplicationSupportCustomPathMatcher() {
 	}
 
 	@Test
+	@SuppressWarnings("removal")
 	void webApplicationConfiguresEndpointDiscoverer() {
 		this.contextRunner.run((context) -> {
 			assertThat(context).hasSingleBean(ControllerEndpointDiscoverer.class);
@@ -109,11 +110,13 @@ void webApplicationConfiguresExposeExcludePropertyEndpointFilter() {
 	}
 
 	@Test
+	@SuppressWarnings("removal")
 	void contextShouldConfigureServletEndpointDiscoverer() {
 		this.contextRunner.run((context) -> assertThat(context).hasSingleBean(ServletEndpointDiscoverer.class));
 	}
 
 	@Test
+	@SuppressWarnings("removal")
 	void contextWhenNotServletShouldNotConfigureServletEndpointDiscoverer() {
 		new ApplicationContextRunner().withConfiguration(CONFIGURATIONS)
 			.run((context) -> assertThat(context).doesNotHaveBean(ServletEndpointDiscoverer.class));

spring-boot-project/spring-boot-actuator-autoconfigure/src/test/java/org/springframework/boot/actuate/autoconfigure/integrationtest/ControllerEndpointWebFluxIntegrationTests.java

@@ -45,6 +45,7 @@
  *
  * @author Phillip Webb
  */
+@SuppressWarnings("removal")
 class ControllerEndpointWebFluxIntegrationTests {
 
 	private AnnotationConfigReactiveWebApplicationContext context;

spring-boot-project/spring-boot-actuator-autoconfigure/src/test/java/org/springframework/boot/actuate/autoconfigure/integrationtest/ControllerEndpointWebMvcIntegrationTests.java

@@ -121,6 +121,7 @@ static class SecureConfiguration {
 	}
 
 	@RestControllerEndpoint(id = "example")
+	@SuppressWarnings("removal")
 	static class ExampleController {
 
 		@GetMapping("/")

spring-boot-project/spring-boot-actuator-autoconfigure/src/test/java/org/springframework/boot/actuate/autoconfigure/integrationtest/JerseyEndpointIntegrationTests.java

@@ -161,11 +161,13 @@ private Class<?>[] getAutoconfigurations(Class<?>... additional) {
 	}
 
 	@ControllerEndpoint(id = "controller")
+	@SuppressWarnings("removal")
 	static class TestControllerEndpoint {
 
 	}
 
 	@RestControllerEndpoint(id = "restcontroller")
+	@SuppressWarnings("removal")
 	static class TestRestControllerEndpoint {
 
 	}