Fix ClassCastException in RAR schema validation for integer keywords

components/api-resource-mgt/org.wso2.carbon.identity.api.resource.mgt/src/main/java/org/wso2/carbon/identity/api/resource/mgt/util/AuthorizationDetailsTypesUtil.java

@@ -19,6 +19,9 @@
 package org.wso2.carbon.identity.api.resource.mgt.util;
 
 import com.google.gson.Gson;
+import com.google.gson.GsonBuilder;
+import com.google.gson.ToNumberPolicy;
+import com.google.gson.ToNumberStrategy;
 import com.google.gson.reflect.TypeToken;
 import org.apache.commons.logging.Log;
 import org.apache.commons.logging.LogFactory;
@@ -36,6 +39,23 @@ public class AuthorizationDetailsTypesUtil {
 
     private static final Log LOG = LogFactory.getLog(AuthorizationDetailsTypesUtil.class);
     private static final Gson GSON = new Gson();
+    /*
+     * By default, Gson parses every JSON number of a Map<String, Object> as a Double. JSON schema validators such as
+     * Vert.x cast integer keywords (e.g. minItems, maxItems) directly to Integer, hence integral values (including
+     * ones written as 1.0) are returned as Integer, or as Long when they exceed the Integer range.
+     */
+    private static final ToNumberStrategy INTEGRAL_PRESERVING_NUMBER_STRATEGY = in -> {
+        final Number number = ToNumberPolicy.LONG_OR_DOUBLE.readNumber(in);
+        final double doubleValue = number.doubleValue();
+        if (doubleValue >= Integer.MIN_VALUE && doubleValue <= Integer.MAX_VALUE
+                && doubleValue == Math.rint(doubleValue)) {
+            return (int) doubleValue;
+        }
+        return number;
+    };
+    private static final Gson INTEGRAL_PRESERVING_GSON = new GsonBuilder()
+            .setObjectToNumberStrategy(INTEGRAL_PRESERVING_NUMBER_STRATEGY)
+            .create();
     private static final Type SCHEMA_TYPE = new TypeToken<Map<String, Object>>() { }.getType();
 
     /**
@@ -49,6 +69,19 @@ public static Map<String, Object> parseSchema(final String schema) {
         return GSON.fromJson(schema, SCHEMA_TYPE);
     }
 
+    /**
+     * Parses a JSON schema into a map structure to be used for authorization details schema validation. Unlike
+     * {@link #parseSchema(String)}, integral numbers are returned as {@code Integer} (or {@code Long}) instead of
+     * {@code Double}, as JSON schema validators expect integer keywords such as {@code minItems} to be integers.
+     *
+     * @param schema the JSON schema string to be parsed. It must be a valid JSON string.
+     * @return a {@code Map<String, Object>} representing the parsed JSON schema.
+     */
+    public static Map<String, Object> parseSchemaForValidation(final String schema) {
+
+        return INTEGRAL_PRESERVING_GSON.fromJson(schema, SCHEMA_TYPE);
+    }
+
     /**
      * Converts a map representing a schema into its JSON string representation.
      *

components/api-resource-mgt/org.wso2.carbon.identity.api.resource.mgt/src/test/java/org/wso2/carbon/identity/api/resource/mgt/AuthorizationDetailsTypesUtilTest.java

@@ -0,0 +1,69 @@
+/*
+ * Copyright (c) 2026, WSO2 LLC. (http://www.wso2.com).
+ *
+ * WSO2 LLC. 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.wso2.carbon.identity.api.resource.mgt;
+
+import org.testng.Assert;
+import org.testng.annotations.Test;
+import org.wso2.carbon.identity.api.resource.mgt.util.AuthorizationDetailsTypesUtil;
+
+import java.util.List;
+import java.util.Map;
+
+/**
+ * Test class for {@link AuthorizationDetailsTypesUtil}.
+ */
+public class AuthorizationDetailsTypesUtilTest {
+
+    private static final String SCHEMA = "{\"type\":\"object\",\"required\":[\"type\"],\"minProperties\":1," +
+            "\"properties\":{\"type\":{\"type\":\"string\",\"const\":\"test_type\"}," +
+            "\"actions\":{\"type\":\"array\",\"items\":{\"type\":\"string\"},\"minItems\":1,\"maxItems\":3.0}," +
+            "\"amount\":{\"type\":\"number\",\"minimum\":0.5,\"maximum\":9999999999}}," +
+            "\"allOf\":[{\"maxProperties\":5}]}";
+
+    @Test
+    @SuppressWarnings("unchecked")
+    public void testParseSchemaForValidationPreservesIntegralValues() {
+
+        final Map<String, Object> schema = AuthorizationDetailsTypesUtil.parseSchemaForValidation(SCHEMA);
+        final Map<String, Object> properties = (Map<String, Object>) schema.get("properties");
+        final Map<String, Object> actions = (Map<String, Object>) properties.get("actions");
+        final Map<String, Object> amount = (Map<String, Object>) properties.get("amount");
+        final Map<String, Object> allOf = ((List<Map<String, Object>>) schema.get("allOf")).get(0);
+
+        Assert.assertEquals(schema.get("minProperties"), 1);
+        Assert.assertEquals(actions.get("minItems"), 1);
+        Assert.assertEquals(actions.get("maxItems"), 3);
+        Assert.assertEquals(allOf.get("maxProperties"), 5);
+        Assert.assertEquals(amount.get("minimum"), 0.5d);
+        Assert.assertEquals(amount.get("maximum"), 9999999999L);
+    }
+
+    @Test
+    @SuppressWarnings("unchecked")
+    public void testParseSchemaKeepsExistingNumberFormat() {
+
+        final Map<String, Object> schema = AuthorizationDetailsTypesUtil.parseSchema(SCHEMA);
+        final Map<String, Object> actions = (Map<String, Object>) ((Map<String, Object>) schema.get("properties"))
+                .get("actions");
+
+        Assert.assertEquals(schema.get("minProperties"), 1.0d);
+        Assert.assertEquals(actions.get("minItems"), 1.0d);
+        Assert.assertEquals(actions.get("maxItems"), 3.0d);
+    }
+}

components/api-resource-mgt/org.wso2.carbon.identity.api.resource.mgt/src/test/resources/testng.xml

@@ -26,6 +26,7 @@
             <class name="org.wso2.carbon.identity.api.resource.mgt.APIResourceManagerTest"/>
             <class name="org.wso2.carbon.identity.api.resource.mgt.APIResourceManagementUtilTest"></class>
             <class name="org.wso2.carbon.identity.api.resource.mgt.AuthorizationDetailsTypeManagerTest"/>
+            <class name="org.wso2.carbon.identity.api.resource.mgt.AuthorizationDetailsTypesUtilTest"/>
             <class name="org.wso2.carbon.identity.api.resource.mgt.dao.CacheBackedAuthorizationDetailsTypeMgtDAOImplTest"/>
         </classes>
     </test>

components/application-mgt/org.wso2.carbon.identity.application.mgt/src/main/java/org/wso2/carbon/identity/application/mgt/dao/impl/AuthorizedAPIDAOImpl.java

@@ -1170,7 +1170,7 @@ private AuthorizationDetailsType buildAuthorizationDetailsTypeWithSchema(ResultS
         final AuthorizationDetailsType authorizationDetailsType = this.buildAuthorizationDetailsType(resultSet);
 
         if (authorizationDetailsType != null) {
-            authorizationDetailsType.setSchema(AuthorizationDetailsTypesUtil.parseSchema(resultSet
+            authorizationDetailsType.setSchema(AuthorizationDetailsTypesUtil.parseSchemaForValidation(resultSet
                     .getString(ApplicationConstants.ApplicationTableColumns.AUTHORIZATION_DETAILS_SCHEMA)));
         }