fix(a2a-server,core-tool): harden host fallback and guard schema definition conflicts

agentscope-core/src/main/java/io/agentscope/core/tool/ToolSchemaGenerator.java

@@ -22,6 +22,7 @@
 import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
+import java.util.Objects;
 import java.util.Set;
 
 /**
@@ -91,15 +92,25 @@ Map<String, Object> generateParameterSchema(Method method, Set<String> excludePa
         return schema;
     }
 
-    // TODO: putAll silently overwrites when different parameters define the same def key
-    //  (e.g. different classes with the same simple name under PLAIN_DEFINITION_KEYS).
-    //  Add value-equality check and fail-fast on true conflicts in a follow-up.
     @SuppressWarnings("unchecked")
     private void hoistDefs(
             Map<String, Object> paramSchema, String key, Map<String, Object> target) {
         Object raw = paramSchema.remove(key);
         if (raw instanceof Map<?, ?> defs && !defs.isEmpty()) {
-            target.putAll((Map<String, Object>) defs);
+            Map<String, Object> normalizedDefs = (Map<String, Object>) defs;
+            for (Map.Entry<String, Object> entry : normalizedDefs.entrySet()) {
+                String defKey = entry.getKey();
+                Object incomingDef = entry.getValue();
+                Object existingDef = target.get(defKey);
+                if (existingDef == null) {
+                    target.put(defKey, incomingDef);
+                    continue;
+                }
+                if (!Objects.equals(existingDef, incomingDef)) {
+                    throw new IllegalStateException(
+                            "Conflicting schema definition found for key: " + defKey);
+                }
+            }
         }
     }
 

agentscope-core/src/test/java/io/agentscope/core/tool/ToolSchemaGeneratorTest.java

@@ -0,0 +1,86 @@
+/*
+ * Copyright 2024-2026 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.
+ * 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 io.agentscope.core.tool;
+
+import static org.junit.jupiter.api.Assertions.assertDoesNotThrow;
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertFalse;
+import static org.junit.jupiter.api.Assertions.assertInstanceOf;
+import static org.junit.jupiter.api.Assertions.assertThrows;
+import static org.junit.jupiter.api.Assertions.assertTrue;
+
+import java.lang.reflect.InvocationTargetException;
+import java.lang.reflect.Method;
+import java.util.HashMap;
+import java.util.Map;
+import org.junit.jupiter.api.DisplayName;
+import org.junit.jupiter.api.Tag;
+import org.junit.jupiter.api.Test;
+
+@Tag("unit")
+@DisplayName("ToolSchemaGenerator Tests")
+class ToolSchemaGeneratorTest {
+
+    private final ToolSchemaGenerator generator = new ToolSchemaGenerator();
+
+    @Test
+    @DisplayName("Should throw when hoisted defs contain conflicting definition for same key")
+    void testHoistDefsConflict() throws Exception {
+        Method hoistDefsMethod =
+                ToolSchemaGenerator.class.getDeclaredMethod(
+                        "hoistDefs", Map.class, String.class, Map.class);
+        hoistDefsMethod.setAccessible(true);
+
+        Map<String, Object> existingDef =
+                Map.of("type", "object", "properties", Map.of("value", Map.of("type", "string")));
+        Map<String, Object> conflictDef =
+                Map.of("type", "object", "properties", Map.of("value", Map.of("type", "integer")));
+
+        Map<String, Object> target = new HashMap<>();
+        target.put("Material", existingDef);
+        Map<String, Object> paramSchema = new HashMap<>();
+        paramSchema.put("$defs", Map.of("Material", conflictDef));
+
+        InvocationTargetException exception =
+                assertThrows(
+                        InvocationTargetException.class,
+                        () -> hoistDefsMethod.invoke(generator, paramSchema, "$defs", target));
+        assertInstanceOf(IllegalStateException.class, exception.getCause());
+        assertTrue(exception.getCause().getMessage().contains("Material"));
+    }
+
+    @Test
+    @DisplayName("Should allow hoisted defs when same key has equivalent definition")
+    void testHoistDefsEquivalent() throws Exception {
+        Method hoistDefsMethod =
+                ToolSchemaGenerator.class.getDeclaredMethod(
+                        "hoistDefs", Map.class, String.class, Map.class);
+        hoistDefsMethod.setAccessible(true);
+
+        Map<String, Object> definition =
+                Map.of("type", "object", "properties", Map.of("value", Map.of("type", "string")));
+
+        Map<String, Object> target = new HashMap<>();
+        target.put("Material", definition);
+        Map<String, Object> paramSchema = new HashMap<>();
+        paramSchema.put("$defs", Map.of("Material", definition));
+
+        assertDoesNotThrow(() -> hoistDefsMethod.invoke(generator, paramSchema, "$defs", target));
+        assertEquals(1, target.size());
+        assertEquals(definition, target.get("Material"));
+        assertFalse(paramSchema.containsKey("$defs"));
+    }
+}

agentscope-extensions/agentscope-extensions-a2a/agentscope-extensions-a2a-server/src/main/java/io/agentscope/core/a2a/server/transport/DeploymentProperties.java

@@ -30,6 +30,7 @@
 public record DeploymentProperties(String host, int port) {
 
     private static final Logger log = LoggerFactory.getLogger(DeploymentProperties.class);
+    private static final String DEFAULT_HOST = "localhost";
 
     public static class Builder {
 
@@ -55,7 +56,12 @@ public DeploymentProperties build() {
                 try {
                     host = NetworkUtils.getLocalIpAddress();
                     log.info("Local IP address: {}", host);
-                } catch (SocketException ignored) {
+                } catch (SocketException exception) {
+                    host = DEFAULT_HOST;
+                    log.warn(
+                            "Failed to resolve local IP address, fallback to default host: {}",
+                            DEFAULT_HOST,
+                            exception);
                 }
             }
             if (null == port) {

agentscope-extensions/agentscope-extensions-a2a/agentscope-extensions-a2a-server/src/test/java/io/agentscope/core/a2a/server/transport/DeploymentPropertiesTest.java

@@ -18,7 +18,6 @@
 
 import static org.junit.jupiter.api.Assertions.assertEquals;
 import static org.junit.jupiter.api.Assertions.assertNotNull;
-import static org.junit.jupiter.api.Assertions.assertNull;
 import static org.junit.jupiter.api.Assertions.assertSame;
 import static org.junit.jupiter.api.Assertions.assertThrows;
 import static org.junit.jupiter.api.Assertions.assertTrue;
@@ -109,7 +108,7 @@ void testUseLocalhostWhenGetLocalIpFails() throws SocketException {
                     new DeploymentProperties.Builder().port(port).build();
 
             assertNotNull(deploymentProperties);
-            assertNull(deploymentProperties.host()); // host will be null since we couldn't get it
+            assertEquals("localhost", deploymentProperties.host());
             assertEquals(port, deploymentProperties.port());
         }