Expose resourcesUpdateConsumer() in sync client

`resourcesUpdateConsumer()` was missing from the sync client. Add it.

Author: Randgalt

mcp-core/src/main/java/io/modelcontextprotocol/client/McpClient.java

@@ -4,17 +4,8 @@
 
 package io.modelcontextprotocol.client;
 
-import java.time.Duration;
-import java.util.ArrayList;
-import java.util.HashMap;
-import java.util.List;
-import java.util.Map;
-import java.util.function.Consumer;
-import java.util.function.Function;
-import java.util.function.Supplier;
-
-import io.modelcontextprotocol.json.schema.JsonSchemaValidator;
 import io.modelcontextprotocol.common.McpTransportContext;
+import io.modelcontextprotocol.json.schema.JsonSchemaValidator;
 import io.modelcontextprotocol.spec.McpClientTransport;
 import io.modelcontextprotocol.spec.McpSchema;
 import io.modelcontextprotocol.spec.McpSchema.ClientCapabilities;
@@ -28,6 +19,15 @@
 import io.modelcontextprotocol.util.Assert;
 import reactor.core.publisher.Mono;
 
+import java.time.Duration;
+import java.util.ArrayList;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+import java.util.function.Consumer;
+import java.util.function.Function;
+import java.util.function.Supplier;
+
 /**
  * Factory class for creating Model Context Protocol (MCP) clients. MCP is a protocol that
  * enables AI models to interact with external tools and resources through a standardized
@@ -346,6 +346,22 @@ public SyncSpec resourcesChangeConsumer(Consumer<List<McpSchema.Resource>> resou
 			return this;
 		}
 
+		/**
+		 * Adds a consumer to be notified when a specific resource is updated. This allows
+		 * the client to react to changes in individual resources, such as updates to
+		 * their content or metadata.
+		 * @param resourcesUpdateConsumer A consumer function that processes the updated
+		 * resource and returns a Mono indicating the completion of the processing. Must
+		 * not be null.
+		 * @return This builder instance for method chaining.
+		 * @throws IllegalArgumentException If the resourcesUpdateConsumer is null.
+		 */
+		public SyncSpec resourcesUpdateConsumer(Consumer<List<McpSchema.ResourceContents>> resourcesUpdateConsumer) {
+			Assert.notNull(resourcesUpdateConsumer, "Resources update consumer must not be null");
+			this.resourcesUpdateConsumers.add(resourcesUpdateConsumer);
+			return this;
+		}
+
 		/**
 		 * Adds a consumer to be notified when the available prompts change. This allows
 		 * the client to react to changes in the server's prompt templates, such as new

mcp-core/src/test/java/io/modelcontextprotocol/client/AbstractMcpSyncClientTests.java

@@ -536,11 +536,13 @@ void testNotificationHandlers() {
 		AtomicBoolean toolsNotificationReceived = new AtomicBoolean(false);
 		AtomicBoolean resourcesNotificationReceived = new AtomicBoolean(false);
 		AtomicBoolean promptsNotificationReceived = new AtomicBoolean(false);
+		AtomicBoolean resourcesUpdatedNotificationReceived = new AtomicBoolean(false);
 
 		withClient(createMcpTransport(),
 				builder -> builder.toolsChangeConsumer(tools -> toolsNotificationReceived.set(true))
 					.resourcesChangeConsumer(resources -> resourcesNotificationReceived.set(true))
-					.promptsChangeConsumer(prompts -> promptsNotificationReceived.set(true)),
+					.promptsChangeConsumer(prompts -> promptsNotificationReceived.set(true))
+					.resourcesUpdateConsumer(resources -> resourcesUpdatedNotificationReceived.set(true)),
 				client -> {
 
 					assertThatCode(() -> {

mcp-test/src/main/java/io/modelcontextprotocol/client/AbstractMcpSyncClientTests.java

@@ -535,11 +535,13 @@ void testNotificationHandlers() {
 		AtomicBoolean toolsNotificationReceived = new AtomicBoolean(false);
 		AtomicBoolean resourcesNotificationReceived = new AtomicBoolean(false);
 		AtomicBoolean promptsNotificationReceived = new AtomicBoolean(false);
+		AtomicBoolean resourcesUpdatedNotificationReceived = new AtomicBoolean(false);
 
 		withClient(createMcpTransport(),
 				builder -> builder.toolsChangeConsumer(tools -> toolsNotificationReceived.set(true))
 					.resourcesChangeConsumer(resources -> resourcesNotificationReceived.set(true))
-					.promptsChangeConsumer(prompts -> promptsNotificationReceived.set(true)),
+					.promptsChangeConsumer(prompts -> promptsNotificationReceived.set(true))
+					.resourcesUpdateConsumer(resources -> resourcesUpdatedNotificationReceived.set(true)),
 				client -> {
 
 					assertThatCode(() -> {