Defer call of getToolCallbacks() to prevent initializing ToolCallbackProvider eagerly

Before this commit, `McpSyncClient` is initialized even if `spring.ai.mcp.client.initialized` is set to `false`.

See GH-3232

Signed-off-by: Yanming Zhou <[email protected]>

Author: quaff

auto-configurations/models/tool/spring-ai-autoconfigure-model-tool/src/main/java/org/springframework/ai/model/tool/autoconfigure/ToolCallingAutoConfiguration.java

@@ -51,6 +51,7 @@
  * @author Thomas Vitale
  * @author Christian Tzolov
  * @author Daniel Garnier-Moiroux
+ * @author Yanming Zhou
  * @since 1.0.0
  */
 @AutoConfiguration
@@ -65,16 +66,23 @@ public class ToolCallingAutoConfiguration {
 	ToolCallbackResolver toolCallbackResolver(GenericApplicationContext applicationContext,
 			List<ToolCallback> toolCallbacks, List<ToolCallbackProvider> tcbProviders) {
 
-		List<ToolCallback> allFunctionAndToolCallbacks = new ArrayList<>(toolCallbacks);
-		tcbProviders.stream().map(pr -> List.of(pr.getToolCallbacks())).forEach(allFunctionAndToolCallbacks::addAll);
+		return toolName -> { // defer call of getToolCallbacks() to prevent initializing
+								// ToolCallbackProvider eagerly
+			List<ToolCallback> allFunctionAndToolCallbacks = new ArrayList<>(toolCallbacks);
+			tcbProviders.stream()
+				.map(pr -> List.of(pr.getToolCallbacks()))
+				.forEach(allFunctionAndToolCallbacks::addAll);
 
-		var staticToolCallbackResolver = new StaticToolCallbackResolver(allFunctionAndToolCallbacks);
+			var staticToolCallbackResolver = new StaticToolCallbackResolver(allFunctionAndToolCallbacks);
 
-		var springBeanToolCallbackResolver = SpringBeanToolCallbackResolver.builder()
-			.applicationContext(applicationContext)
-			.build();
+			var springBeanToolCallbackResolver = SpringBeanToolCallbackResolver.builder()
+				.applicationContext(applicationContext)
+				.build();
 
-		return new DelegatingToolCallbackResolver(List.of(staticToolCallbackResolver, springBeanToolCallbackResolver));
+			return new DelegatingToolCallbackResolver(
+					List.of(staticToolCallbackResolver, springBeanToolCallbackResolver))
+				.resolve(toolName);
+		};
 	}
 
 	@Bean

auto-configurations/models/tool/spring-ai-autoconfigure-model-tool/src/test/java/org/springframework/ai/model/tool/autoconfigure/ToolCallingAutoConfigurationTests.java

@@ -19,6 +19,7 @@
 import java.util.function.Function;
 
 import org.junit.jupiter.api.Test;
+import org.mockito.Mockito;
 
 import org.springframework.ai.model.tool.DefaultToolCallingManager;
 import org.springframework.ai.model.tool.ToolCallingManager;
@@ -34,7 +35,6 @@
 import org.springframework.ai.tool.method.MethodToolCallback;
 import org.springframework.ai.tool.method.MethodToolCallbackProvider;
 import org.springframework.ai.tool.observation.ToolCallingContentObservationFilter;
-import org.springframework.ai.tool.resolution.DelegatingToolCallbackResolver;
 import org.springframework.ai.tool.resolution.ToolCallbackResolver;
 import org.springframework.ai.tool.support.ToolDefinitions;
 import org.springframework.boot.autoconfigure.AutoConfigurations;
@@ -45,21 +45,24 @@
 import org.springframework.util.ReflectionUtils;
 
 import static org.assertj.core.api.Assertions.assertThat;
+import static org.mockito.BDDMockito.then;
+import static org.mockito.Mockito.never;
+import static org.mockito.Mockito.times;
 
 /**
  * Unit tests for {@link ToolCallingAutoConfiguration}.
  *
  * @author Thomas Vitale
  * @author Christian Tzolov
+ * @author Yanming Zhou
  */
 class ToolCallingAutoConfigurationTests {
 
 	@Test
 	void beansAreCreated() {
 		new ApplicationContextRunner().withConfiguration(AutoConfigurations.of(ToolCallingAutoConfiguration.class))
 			.run(context -> {
-				var toolCallbackResolver = context.getBean(ToolCallbackResolver.class);
-				assertThat(toolCallbackResolver).isInstanceOf(DelegatingToolCallbackResolver.class);
+				assertThat(context).hasSingleBean(ToolCallbackResolver.class);
 
 				var toolExecutionExceptionProcessor = context.getBean(ToolExecutionExceptionProcessor.class);
 				assertThat(toolExecutionExceptionProcessor).isInstanceOf(DefaultToolExecutionExceptionProcessor.class);
@@ -69,13 +72,25 @@ void beansAreCreated() {
 			});
 	}
 
+	@Test
+	void deferGetToolCallbacks() {
+		new ApplicationContextRunner().withConfiguration(AutoConfigurations.of(ToolCallingAutoConfiguration.class))
+			.withUserConfiguration(Config.class)
+			.run(context -> {
+				var toolCallbackResolver = context.getBean(ToolCallbackResolver.class);
+				var toolCallbackProvider = context.getBean("toolCallbacks", ToolCallbackProvider.class);
+				then(toolCallbackProvider).should(never()).getToolCallbacks();
+				assertThat(toolCallbackResolver.resolve("getForecast")).isNotNull();
+				then(toolCallbackProvider).should(times(1)).getToolCallbacks();
+			});
+	}
+
 	@Test
 	void resolveMultipleFunctionAndToolCallbacks() {
 		new ApplicationContextRunner().withConfiguration(AutoConfigurations.of(ToolCallingAutoConfiguration.class))
 			.withUserConfiguration(Config.class)
 			.run(context -> {
 				var toolCallbackResolver = context.getBean(ToolCallbackResolver.class);
-				assertThat(toolCallbackResolver).isInstanceOf(DelegatingToolCallbackResolver.class);
 
 				assertThat(toolCallbackResolver.resolve("getForecast")).isNotNull();
 				assertThat(toolCallbackResolver.resolve("getForecast").getToolDefinition().name())
@@ -108,7 +123,6 @@ void resolveMissingToolCallbacks() {
 			.withUserConfiguration(Config.class)
 			.run(context -> {
 				var toolCallbackResolver = context.getBean(ToolCallbackResolver.class);
-				assertThat(toolCallbackResolver).isInstanceOf(DelegatingToolCallbackResolver.class);
 
 				assertThat(toolCallbackResolver.resolve("NonExisting")).isNull();
 			});
@@ -212,7 +226,10 @@ static class Config {
 		// ToolCallbacks.from(...) utility method.
 		@Bean
 		public ToolCallbackProvider toolCallbacks() {
-			return MethodToolCallbackProvider.builder().toolObjects(new WeatherService()).build();
+			ToolCallbackProvider toolCallbackProvider = MethodToolCallbackProvider.builder()
+				.toolObjects(new WeatherService())
+				.build();
+			return Mockito.spy(toolCallbackProvider);
 		}
 
 		@Bean