spring-projectsGH-3379: Spring Boot 4.x compatibility

- Updated Spring Boot dependency to 4.0.0.RC1
- Spring Framework 7 API compatibility (see below)
- Migration to Spring Boot 4.x as per https://github.com/spring-projects/spring-boot/wiki/Spring-Boot-4.0-Migration-Guide :
  * Adopt new modular design of starters
  * Use new Jackson 3.x API
  * Support Property Mapper API changes around null handling
  * Migrated from Spring Retry to Spring Framework Retry functionality
- Updated Swagger codegen templates used by huggingface model to align with latest Spring Framework APIs
- Update elasticsearch test container to 9.2.0
- Added `FailureDetectingExternalResource` from old versions of `testcontainers` library to support `gemfire-testcontainers`
- Other related dependencies updates:
  * TestContainers to 2.0.1
  * GemFire testcontainers to 2.3.3
  * opensearch-testcontainers to 4.0.0
  * Rest Assured to 5.5.6
  * swagger-codegen-maven-plugin to 3.0.75

Fixes spring-projectsGH-3379 (spring-projects#3379)

Includes changes by @paulbakker from spring-projects#4681

Built on-top of spring-projects#4771
- Use only Spring Framework APIs available both in 6.x and 7.x branches
- Add constructors without logic to `*Api` classes in `models` modules to simplify extensibility; effective final fields are marked as final
- Kotlin 2.x support; use kotlin compiler version 2.2.21
- Update MCP SDK to 0.15.0
- Update MCP Annotations to 0.6.0

Future tasks:
- [x] Raise issue to migrate from Spring Retry to Spring Framework 7 built-in retry functionality: spring-projects#4681
- [ ] Raise issue with `swagger-codegen-maven-plugin` to support Spring Framework 7
- [x] Raise issue with GemFire to support testcontainers 2.x: gemfire/gemfire-testcontainers#7

Signed-off-by: Dmitry Bedrin <dmitry.bedrin@gmail.com>

- Rebase, resolve conflicts and fix compilation and configuratino issues
- Fix ObjectMapper JsonMapper test discrepancy
- Downgrade opensearch testcontainers to 2.0.1 for java 17 compatibility

Signed-off-by: Christian Tzolov <christian.tzolov@broadcom.com>

Author: bedrin

auto-configurations/common/spring-ai-autoconfigure-retry/pom.xml

@@ -61,6 +61,11 @@
 			<artifactId>spring-boot-starter-test</artifactId>
 			<scope>test</scope>
 		</dependency>
+		<dependency>
+			<groupId>org.springframework.boot</groupId>
+			<artifactId>spring-boot-starter-restclient-test</artifactId>
+			<scope>test</scope>
+		</dependency>
 
 		<dependency>
 			<groupId>org.mockito</groupId>

auto-configurations/common/spring-ai-autoconfigure-retry/src/main/java/org/springframework/ai/retry/autoconfigure/SpringAiRetryAutoConfiguration.java

@@ -17,7 +17,9 @@
 package org.springframework.ai.retry.autoconfigure;
 
 import java.io.IOException;
+import java.net.URI;
 import java.nio.charset.StandardCharsets;
+import java.util.concurrent.atomic.AtomicInteger;
 
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
@@ -30,16 +32,15 @@
 import org.springframework.boot.autoconfigure.condition.ConditionalOnMissingBean;
 import org.springframework.boot.context.properties.EnableConfigurationProperties;
 import org.springframework.context.annotation.Bean;
+import org.springframework.core.retry.RetryListener;
+import org.springframework.core.retry.RetryPolicy;
+import org.springframework.core.retry.RetryTemplate;
+import org.springframework.core.retry.Retryable;
+import org.springframework.http.HttpMethod;
 import org.springframework.http.client.ClientHttpResponse;
 import org.springframework.lang.NonNull;
-import org.springframework.retry.RetryCallback;
-import org.springframework.retry.RetryContext;
-import org.springframework.retry.RetryListener;
-import org.springframework.retry.support.RetryTemplate;
-import org.springframework.retry.support.RetryTemplateBuilder;
 import org.springframework.util.CollectionUtils;
 import org.springframework.util.StreamUtils;
-import org.springframework.web.client.ResourceAccessException;
 import org.springframework.web.client.ResponseErrorHandler;
 
 /**
@@ -61,35 +62,25 @@ public class SpringAiRetryAutoConfiguration {
 	@Bean
 	@ConditionalOnMissingBean
 	public RetryTemplate retryTemplate(SpringAiRetryProperties properties) {
-		RetryTemplateBuilder builder = RetryTemplate.builder()
+		RetryPolicy retryPolicy = RetryPolicy.builder()
 			.maxAttempts(properties.getMaxAttempts())
-			.retryOn(TransientAiException.class)
-			.retryOn(ResourceAccessException.class)
-			.exponentialBackoff(properties.getBackoff().getInitialInterval(), properties.getBackoff().getMultiplier(),
-					properties.getBackoff().getMaxInterval())
-			.withListener(new RetryListener() {
-
-				@Override
-				public <T, E extends Throwable> void onError(RetryContext context, RetryCallback<T, E> callback,
-						Throwable throwable) {
-					logger.warn("Retry error. Retry count: {}, Exception: {}", context.getRetryCount(),
-							throwable.getMessage(), throwable);
-				}
-			});
-
-		// Optionally add WebFlux pre-response network errors if present
-		try {
-			Class<?> webClientRequestEx = Class
-				.forName("org.springframework.web.reactive.function.client.WebClientRequestException");
-			@SuppressWarnings("unchecked")
-			Class<? extends Throwable> exClass = (Class<? extends Throwable>) webClientRequestEx;
-			builder.retryOn(exClass);
-		}
-		catch (ClassNotFoundException ignore) {
-			// WebFlux not on classpath; skip
-		}
-
-		return builder.build();
+			.includes(TransientAiException.class)
+			.delay(properties.getBackoff().getInitialInterval())
+			.multiplier(properties.getBackoff().getMultiplier())
+			.maxDelay(properties.getBackoff().getMaxInterval())
+			.build();
+
+		RetryTemplate retryTemplate = new RetryTemplate(retryPolicy);
+		retryTemplate.setRetryListener(new RetryListener() {
+			private final AtomicInteger retryCount = new AtomicInteger(0);
+
+			@Override
+			public void onRetryFailure(RetryPolicy policy, Retryable<?> retryable, Throwable throwable) {
+				int currentRetries = this.retryCount.incrementAndGet();
+				logger.warn("Retry error. Retry count:{}", currentRetries, throwable);
+			}
+		});
+		return retryTemplate;
 	}
 
 	@Bean
@@ -104,6 +95,12 @@ public boolean hasError(@NonNull ClientHttpResponse response) throws IOException
 			}
 
 			@Override
+			public void handleError(@NonNull URI url, @NonNull HttpMethod method, @NonNull ClientHttpResponse response)
+					throws IOException {
+				handleError(response);
+			}
+
+			@SuppressWarnings("removal")
 			public void handleError(@NonNull ClientHttpResponse response) throws IOException {
 				if (!response.getStatusCode().isError()) {
 					return;

auto-configurations/common/spring-ai-autoconfigure-retry/src/test/java/org/springframework/ai/retry/autoconfigure/SpringAiRetryAutoConfigurationIT.java

@@ -19,9 +19,9 @@
 import org.junit.jupiter.api.Test;
 
 import org.springframework.boot.autoconfigure.AutoConfigurations;
-import org.springframework.boot.autoconfigure.web.client.RestClientAutoConfiguration;
+import org.springframework.boot.restclient.autoconfigure.RestClientAutoConfiguration;
 import org.springframework.boot.test.context.runner.ApplicationContextRunner;
-import org.springframework.retry.support.RetryTemplate;
+import org.springframework.core.retry.RetryTemplate;
 import org.springframework.web.client.ResponseErrorHandler;
 
 import static org.assertj.core.api.Assertions.assertThat;

auto-configurations/mcp/spring-ai-autoconfigure-mcp-client-httpclient/pom.xml

@@ -82,7 +82,7 @@
 
 		<dependency>
 			<groupId>org.testcontainers</groupId>
-			<artifactId>junit-jupiter</artifactId>
+			<artifactId>testcontainers-junit-jupiter</artifactId>
 			<scope>test</scope>
 		</dependency>
 	</dependencies>

auto-configurations/mcp/spring-ai-autoconfigure-mcp-client-webflux/pom.xml

@@ -88,7 +88,7 @@
 
 		<dependency>
 			<groupId>org.testcontainers</groupId>
-			<artifactId>junit-jupiter</artifactId>
+			<artifactId>testcontainers-junit-jupiter</artifactId>
 			<scope>test</scope>
 		</dependency>
 

auto-configurations/mcp/spring-ai-autoconfigure-mcp-server-webflux/pom.xml

@@ -95,6 +95,17 @@
 			<scope>test</scope>
 		</dependency>
 
+		<dependency>
+			<groupId>org.springframework.boot</groupId>
+			<artifactId>spring-boot-starter-restclient</artifactId>
+			<scope>test</scope>
+		</dependency>
+		<dependency>
+			<groupId>org.springframework.boot</groupId>
+			<artifactId>spring-boot-starter-webclient</artifactId>
+			<scope>test</scope>
+		</dependency>
+
 		<dependency>
 			<groupId>org.springframework.ai</groupId>
 			<artifactId>spring-ai-autoconfigure-model-anthropic</artifactId>

auto-configurations/mcp/spring-ai-autoconfigure-mcp-server-webflux/src/test/java/org/springframework/ai/mcp/server/autoconfigure/McpServerSseWebFluxAutoConfigurationTests.java

@@ -16,7 +16,7 @@
 
 package org.springframework.ai.mcp.server.autoconfigure;
 
-import com.fasterxml.jackson.databind.ObjectMapper;
+import com.fasterxml.jackson.databind.json.JsonMapper;
 import io.modelcontextprotocol.server.transport.WebFluxSseServerTransportProvider;
 import org.junit.jupiter.api.Test;
 
@@ -43,10 +43,11 @@ void shouldConfigureWebFluxTransportWithCustomObjectMapper() {
 			assertThat(context).hasSingleBean(RouterFunction.class);
 			assertThat(context).hasSingleBean(McpServerProperties.class);
 
-			ObjectMapper objectMapper = context.getBean("mcpServerObjectMapper", ObjectMapper.class);
+			JsonMapper jsonMapper = context.getBean("mcpServerObjectMapper", JsonMapper.class);
 
-			// Verify that the ObjectMapper is configured to ignore unknown properties
-			assertThat(objectMapper.getDeserializationConfig()
+			// Verify that the JsonMapper is configured to ignore unknown properties
+
+			assertThat(jsonMapper
 				.isEnabled(com.fasterxml.jackson.databind.DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES)).isFalse();
 
 			// Test with a JSON payload containing unknown fields
@@ -61,7 +62,7 @@ void shouldConfigureWebFluxTransportWithCustomObjectMapper() {
 			// CHECKSTYLE:ON
 
 			// This should not throw an exception
-			TestMessage message = objectMapper.readValue(jsonWithUnknownField, TestMessage.class);
+			TestMessage message = jsonMapper.readValue(jsonWithUnknownField, TestMessage.class);
 			assertThat(message.getName()).isEqualTo("test");
 		});
 	}

auto-configurations/mcp/spring-ai-autoconfigure-mcp-server-webflux/src/test/java/org/springframework/ai/mcp/server/autoconfigure/McpToolCallProviderCachingIT.java

@@ -48,9 +48,9 @@
 import org.springframework.ai.tool.ToolCallbackProvider;
 import org.springframework.ai.tool.function.FunctionToolCallback;
 import org.springframework.boot.autoconfigure.AutoConfigurations;
-import org.springframework.boot.autoconfigure.web.client.RestClientAutoConfiguration;
-import org.springframework.boot.autoconfigure.web.reactive.function.client.WebClientAutoConfiguration;
+import org.springframework.boot.restclient.autoconfigure.RestClientAutoConfiguration;
 import org.springframework.boot.test.context.runner.ApplicationContextRunner;
+import org.springframework.boot.webclient.autoconfigure.WebClientAutoConfiguration;
 import org.springframework.context.ApplicationContext;
 import org.springframework.context.annotation.Bean;
 import org.springframework.http.server.reactive.HttpHandler;

auto-configurations/mcp/spring-ai-autoconfigure-mcp-server-webflux/src/test/java/org/springframework/ai/mcp/server/autoconfigure/McpToolCallbackParameterlessToolIT.java

@@ -48,9 +48,9 @@
 import org.springframework.ai.tool.ToolCallbackProvider;
 import org.springframework.ai.tool.definition.ToolDefinition;
 import org.springframework.boot.autoconfigure.AutoConfigurations;
-import org.springframework.boot.autoconfigure.web.client.RestClientAutoConfiguration;
-import org.springframework.boot.autoconfigure.web.reactive.function.client.WebClientAutoConfiguration;
+import org.springframework.boot.restclient.autoconfigure.RestClientAutoConfiguration;
 import org.springframework.boot.test.context.runner.ApplicationContextRunner;
+import org.springframework.boot.webclient.autoconfigure.WebClientAutoConfiguration;
 import org.springframework.context.ApplicationContext;
 import org.springframework.http.server.reactive.HttpHandler;
 import org.springframework.http.server.reactive.ReactorHttpHandlerAdapter;

auto-configurations/mcp/spring-ai-autoconfigure-mcp-server-webflux/src/test/java/org/springframework/ai/mcp/server/autoconfigure/StreamableMcpAnnotationsWithLLMIT.java

@@ -64,9 +64,9 @@
 import org.springframework.ai.retry.autoconfigure.SpringAiRetryAutoConfiguration;
 import org.springframework.ai.tool.ToolCallbackProvider;
 import org.springframework.boot.autoconfigure.AutoConfigurations;
-import org.springframework.boot.autoconfigure.web.client.RestClientAutoConfiguration;
-import org.springframework.boot.autoconfigure.web.reactive.function.client.WebClientAutoConfiguration;
+import org.springframework.boot.restclient.autoconfigure.RestClientAutoConfiguration;
 import org.springframework.boot.test.context.runner.ApplicationContextRunner;
+import org.springframework.boot.webclient.autoconfigure.WebClientAutoConfiguration;
 import org.springframework.context.ApplicationContext;
 import org.springframework.context.annotation.Bean;
 import org.springframework.context.annotation.ComponentScan;