[Feature][Java] Add MCP support in Java

.github/workflows/ci.yml

@@ -63,8 +63,24 @@ jobs:
         with:
           java-version: ${{ matrix.java-version }}
           distribution: 'adopt'
+      - name: Install python
+        uses: actions/setup-python@v4
+        with:
+          python-version: '3.11'
+      - name: Install uv
+        uses: astral-sh/setup-uv@v4
+        with:
+          version: "latest"
+      - name: Install Python dependencies for MCP tests
+        run: |
+          cd python
+          uv sync --all-extras
       - name: Run Java Tests
-        run: tools/ut.sh -j
+        run: |
+          # Add Python venv to PATH so Java tests can find MCP dependencies
+          export PATH="${{ github.workspace }}/python/.venv/bin:$PATH"
+          export PYTHONPATH="${{ github.workspace }}/python/.venv/lib/python3.11/site-packages:$PYTHONPATH"
+          tools/ut.sh -j
 
   python_tests:
     name: ut-python [${{ matrix.os }}] [python-${{ matrix.python-version}}]

api/pom.xml

@@ -65,4 +65,26 @@ under the License.
         </dependency>
     </dependencies>
 
+    <profiles>
+        <profile>
+            <id>java-11</id>
+            <activation>
+                <jdk>[11,17)</jdk>
+            </activation>
+            <build>
+                <plugins>
+                    <plugin>
+                        <groupId>org.apache.maven.plugins</groupId>
+                        <artifactId>maven-compiler-plugin</artifactId>
+                        <configuration>
+                            <excludes>
+                                <exclude>org/apache/flink/agents/api/annotation/MCPServer.java</exclude>
+                            </excludes>
+                        </configuration>
+                    </plugin>
+                </plugins>
+            </build>
+        </profile>
+    </profiles>
+
 </project>

api/src/main/java/org/apache/flink/agents/api/agents/ReActAgent.java

@@ -91,7 +91,7 @@ public ReActAgent(
                         "Output schema must be RowTypeInfo or Pojo class.");
             }
             Prompt schemaPrompt =
-                    new Prompt(
+                    Prompt.fromText(
                             String.format(
                                     "The final response should be json format, and match the schema %s",
                                     jsonSchema));

api/src/main/java/org/apache/flink/agents/api/annotation/MCPServer.java

@@ -0,0 +1,68 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.apache.flink.agents.api.annotation;
+
+import java.lang.annotation.ElementType;
+import java.lang.annotation.Retention;
+import java.lang.annotation.RetentionPolicy;
+import java.lang.annotation.Target;
+
+/**
+ * Annotation to mark a method as an MCP server resource that should be managed by the agent plan.
+ *
+ * <p>Methods annotated with @MCPServer will be scanned during agent plan creation. The agent plan
+ * will automatically:
+ *
+ * <ul>
+ *   <li>Discover all tools exposed by the MCP server via {@code listTools()}
+ *   <li>Discover all prompts exposed by the MCP server via {@code listPrompts()}
+ *   <li>Register each tool and prompt as individual resources
+ *   <li>Close the MCP server connection after discovery
+ * </ul>
+ *
+ * <p>Example usage:
+ *
+ * <pre>{@code
+ * public class MyAgent extends Agent {
+ *     @MCPServer
+ *     public static MCPServer myMcpServer() {
+ *         return MCPServer.builder("http://localhost:8000/mcp")
+ *             .timeout(Duration.ofSeconds(30))
+ *             .build();
+ *     }
+ *
+ *     @ChatModelSetup
+ *     public static ChatModel chatModel() {
+ *         return new ChatModel.Builder()
+ *             .prompt("greeting")  // MCP prompt from server
+ *             .tools(List.of("calculator"))  // MCP tool from server
+ *             .build();
+ *     }
+ * }
+ * }</pre>
+ *
+ * <p>This is the Java equivalent of Python's {@code @mcp_server} decorator.
+ *
+ * @see org.apache.flink.agents.integrations.mcp.MCPServer
+ * @see org.apache.flink.agents.integrations.mcp.MCPTool
+ * @see org.apache.flink.agents.integrations.mcp.MCPPrompt
+ */
+@Target(ElementType.METHOD)
+@Retention(RetentionPolicy.RUNTIME)
+public @interface MCPServer {}