Expose RemoveJsonAttributesResponseBody YAML shortcut on MVC

spring-cloud-gateway-server-webmvc/src/main/java/org/springframework/cloud/gateway/server/mvc/config/NormalizedOperationMethod.java

@@ -17,6 +17,7 @@
 package org.springframework.cloud.gateway.server.mvc.config;
 
 import java.lang.reflect.Method;
+import java.util.ArrayList;
 import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
@@ -104,13 +105,42 @@ private Map<String, Object> normalizeArgs(Map<String, Object> operationArgs) {
 						map.put(fieldName, StringUtils.collectionToCommaDelimitedString(operationArgs.values()));
 						yield map;
 					}
-					default -> throw new IllegalArgumentException("Unknown Shortcut type " + shortcut.type());
+					case LIST_TAIL_FLAG -> normalizeListTailFlag(operationArgs, fieldOrder);
 				};
 			}
 		}
 		return operationArgs;
 	}
 
+	private static Map<String, Object> normalizeListTailFlag(Map<String, Object> operationArgs, String[] fieldOrder) {
+		// field order: list field name, then optional boolean tail flag.
+		// Unlike reactive GATHER_LIST_TAIL_FLAG (omits/nulls the flag when absent),
+		// always
+		// emit false so a primitive boolean param binds safely for the MVC invoker.
+		Assert.isTrue(fieldOrder != null && fieldOrder.length == 2,
+				"Shortcut Configuration Type LIST_TAIL_FLAG must have shortcutFieldOrder of size 2");
+		List<Object> values = new ArrayList<>(operationArgs.values());
+		Object flagValue = Boolean.FALSE;
+		if (!values.isEmpty()) {
+			int lastIdx = values.size() - 1;
+			Object lastValue = values.get(lastIdx);
+			if (lastValue == null) {
+				values = values.subList(0, lastIdx);
+			}
+			else {
+				String lastString = lastValue.toString();
+				if ("true".equalsIgnoreCase(lastString) || "false".equalsIgnoreCase(lastString)) {
+					values = values.subList(0, lastIdx);
+					flagValue = Boolean.valueOf(lastString);
+				}
+			}
+		}
+		Map<String, Object> map = new HashMap<>();
+		map.put(fieldOrder[0], new ArrayList<>(values));
+		map.put(fieldOrder[1], flagValue);
+		return map;
+	}
+
 	private String[] getFieldOrder(Shortcut shortcut) {
 		String[] fieldOrder = shortcut.fieldOrder();
 		if (fieldOrder.length == 0) {

spring-cloud-gateway-server-webmvc/src/main/java/org/springframework/cloud/gateway/server/mvc/filter/FilterFunctions.java

@@ -17,11 +17,13 @@
 package org.springframework.cloud.gateway.server.mvc.filter;
 
 import java.net.URI;
+import java.util.List;
 import java.util.function.Consumer;
 
 import org.springframework.cloud.gateway.server.mvc.common.HttpStatusHolder;
 import org.springframework.cloud.gateway.server.mvc.common.KeyValues;
 import org.springframework.cloud.gateway.server.mvc.common.Shortcut;
+import org.springframework.cloud.gateway.server.mvc.common.Shortcut.Type;
 import org.springframework.cloud.gateway.server.mvc.filter.AfterFilterFunctions.DedupeStrategy;
 import org.springframework.cloud.gateway.server.mvc.filter.BeforeFilterFunctions.FallbackHeadersConfig;
 import org.springframework.http.HttpHeaders;
@@ -148,6 +150,21 @@ static HandlerFilterFunction<ServerResponse, ServerResponse> removeResponseHeade
 		return ofResponseProcessor(AfterFilterFunctions.removeResponseHeader(name));
 	}
 
+	/**
+	 * YAML / properties shortcut for
+	 * {@link AfterFilterFunctions#removeJsonAttributesResponseBody(List, boolean)}.
+	 * Supports {@code RemoveJsonAttributesResponseBody=id,color} and an optional trailing
+	 * boolean for recursive deletion ({@code ...,true}).
+	 * @param fieldList JSON attribute names to remove
+	 * @param deleteRecursively whether to remove nested attributes
+	 * @return the filter function
+	 */
+	@Shortcut(type = Type.LIST_TAIL_FLAG, fieldOrder = { "fieldList", "deleteRecursively" })
+	static HandlerFilterFunction<ServerResponse, ServerResponse> removeJsonAttributesResponseBody(
+			List<String> fieldList, boolean deleteRecursively) {
+		return ofResponseProcessor(AfterFilterFunctions.removeJsonAttributesResponseBody(fieldList, deleteRecursively));
+	}
+
 	@Shortcut
 	static HandlerFilterFunction<ServerResponse, ServerResponse> requestHeaderSize(String maxSize) {
 		return ofRequestProcessor(BeforeFilterFunctions.requestHeaderSize(maxSize));

spring-cloud-gateway-server-webmvc/src/test/java/org/springframework/cloud/gateway/server/mvc/config/NormalizedOperationMethodTests.java

@@ -0,0 +1,107 @@
+/*
+ * Copyright 2013-present 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
+ *
+ *      https://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.springframework.cloud.gateway.server.mvc.config;
+
+import java.lang.reflect.Method;
+import java.util.LinkedHashMap;
+import java.util.List;
+import java.util.Map;
+
+import org.junit.jupiter.api.Test;
+
+import org.springframework.cloud.gateway.server.mvc.common.NameUtils;
+import org.springframework.cloud.gateway.server.mvc.common.Shortcut;
+import org.springframework.cloud.gateway.server.mvc.common.Shortcut.Type;
+import org.springframework.cloud.gateway.server.mvc.invoke.reflect.DefaultOperationMethod;
+import org.springframework.web.servlet.function.HandlerFilterFunction;
+import org.springframework.web.servlet.function.ServerResponse;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+/**
+ * @author Burak Kalayci
+ */
+class NormalizedOperationMethodTests {
+
+	@Test
+	void listTailFlagWithoutTrailingBooleanKeepsFieldsAndDefaultsFlagFalse() throws Exception {
+		Method method = SampleFilters.class.getDeclaredMethod("removeJsonAttributesResponseBody", List.class,
+				boolean.class);
+		Map<String, Object> args = new LinkedHashMap<>();
+		args.put(NameUtils.generateName(0), "id");
+		args.put(NameUtils.generateName(1), "color");
+
+		NormalizedOperationMethod operationMethod = new NormalizedOperationMethod(new DefaultOperationMethod(method),
+				args);
+		Map<String, Object> normalized = operationMethod.getNormalizedArgs();
+
+		assertThat(normalized).containsOnlyKeys("fieldList", "deleteRecursively");
+		assertThat(normalized.get("fieldList")).isInstanceOf(List.class);
+		@SuppressWarnings("unchecked")
+		List<Object> fieldList = (List<Object>) normalized.get("fieldList");
+		assertThat(fieldList).containsExactly("id", "color");
+		assertThat(normalized.get("deleteRecursively")).isEqualTo(Boolean.FALSE);
+	}
+
+	@Test
+	void listTailFlagWithTrailingBooleanStripsFlagFromFieldList() throws Exception {
+		Method method = SampleFilters.class.getDeclaredMethod("removeJsonAttributesResponseBody", List.class,
+				boolean.class);
+		Map<String, Object> args = new LinkedHashMap<>();
+		args.put(NameUtils.generateName(0), "id");
+		args.put(NameUtils.generateName(1), "color");
+		args.put(NameUtils.generateName(2), "true");
+
+		NormalizedOperationMethod operationMethod = new NormalizedOperationMethod(new DefaultOperationMethod(method),
+				args);
+		Map<String, Object> normalized = operationMethod.getNormalizedArgs();
+
+		@SuppressWarnings("unchecked")
+		List<Object> fieldList = (List<Object>) normalized.get("fieldList");
+		assertThat(fieldList).containsExactly("id", "color");
+		assertThat(normalized.get("deleteRecursively")).isEqualTo(Boolean.TRUE);
+	}
+
+	@Test
+	void listTailFlagIgnoresNonBooleanTrailingValue() throws Exception {
+		Method method = SampleFilters.class.getDeclaredMethod("removeJsonAttributesResponseBody", List.class,
+				boolean.class);
+		Map<String, Object> args = new LinkedHashMap<>();
+		args.put(NameUtils.generateName(0), "id");
+		args.put(NameUtils.generateName(1), "notAFlag");
+
+		NormalizedOperationMethod operationMethod = new NormalizedOperationMethod(new DefaultOperationMethod(method),
+				args);
+		Map<String, Object> normalized = operationMethod.getNormalizedArgs();
+
+		@SuppressWarnings("unchecked")
+		List<Object> fieldList = (List<Object>) normalized.get("fieldList");
+		assertThat(fieldList).containsExactly("id", "notAFlag");
+		assertThat(normalized.get("deleteRecursively")).isEqualTo(Boolean.FALSE);
+	}
+
+	static final class SampleFilters {
+
+		@Shortcut(type = Type.LIST_TAIL_FLAG, fieldOrder = { "fieldList", "deleteRecursively" })
+		static HandlerFilterFunction<ServerResponse, ServerResponse> removeJsonAttributesResponseBody(
+				List<String> fieldList, boolean deleteRecursively) {
+			return (request, next) -> next.handle(request);
+		}
+
+	}
+
+}

spring-cloud-gateway-server-webmvc/src/test/java/org/springframework/cloud/gateway/server/mvc/config/RemoveJsonAttributesResponseBodyShortcutTests.java

@@ -0,0 +1,108 @@
+/*
+ * Copyright 2013-present 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
+ *
+ *      https://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.springframework.cloud.gateway.server.mvc.config;
+
+import java.util.Map;
+
+import org.junit.jupiter.api.BeforeAll;
+import org.junit.jupiter.api.Test;
+
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.boot.SpringBootConfiguration;
+import org.springframework.boot.autoconfigure.EnableAutoConfiguration;
+import org.springframework.boot.test.context.SpringBootTest;
+import org.springframework.boot.test.context.SpringBootTest.WebEnvironment;
+import org.springframework.cloud.gateway.server.mvc.test.HttpbinTestcontainers;
+import org.springframework.cloud.gateway.server.mvc.test.PermitAllSecurityConfiguration;
+import org.springframework.cloud.gateway.server.mvc.test.TestLoadBalancerConfig;
+import org.springframework.cloud.loadbalancer.annotation.LoadBalancerClient;
+import org.springframework.context.annotation.Import;
+import org.springframework.http.HttpHeaders;
+import org.springframework.http.MediaType;
+import org.springframework.test.context.ActiveProfiles;
+import org.springframework.test.context.ContextConfiguration;
+import org.springframework.test.web.servlet.client.RestTestClient;
+
+import static org.assertj.core.api.Assertions.assertThat;
+import static org.springframework.cloud.gateway.server.mvc.test.TestUtils.getMap;
+
+/**
+ * End-to-end coverage for the YAML/properties shortcut path of
+ * {@code RemoveJsonAttributesResponseBody} (registration → invoke → live filter), which
+ * is the failure mode reported in gh-4240.
+ *
+ * @author Burak Kalayci
+ */
+@SpringBootTest(webEnvironment = WebEnvironment.RANDOM_PORT)
+@ActiveProfiles("removejsonattributesshortcuttests")
+@ContextConfiguration(initializers = HttpbinTestcontainers.class)
+class RemoveJsonAttributesResponseBodyShortcutTests {
+
+	@Autowired
+	RestTestClient restClient;
+
+	@BeforeAll
+	static void beforeAll() {
+		HttpbinTestcontainers.initializeSystemProperties();
+	}
+
+	@Test
+	@SuppressWarnings("unchecked")
+	void shortcutWithoutFlagBuildsRouteAndStripsRootAttributes() {
+		restClient.get().uri("/get").exchange().expectStatus().isOk().expectBody(Map.class).consumeWith(res -> {
+			Map<String, Object> body = res.getResponseBody();
+			assertThat(body).isNotNull();
+			// shortcut resolved (no "Unable to find operation") and filter applied
+			assertThat(body).doesNotContainKeys("origin", "url");
+			assertThat(body).containsKey("headers");
+		});
+	}
+
+	@Test
+	@SuppressWarnings("unchecked")
+	void shortcutWithTrailingTrueBuildsRouteAndStripsNestedAttributes() {
+		restClient.post()
+			.uri("/post")
+			.header(HttpHeaders.CONTENT_TYPE, MediaType.APPLICATION_JSON_VALUE)
+			.header("Foo", "remove-me")
+			.header("Bar", "keep-me")
+			.body("{}")
+			.exchange()
+			.expectStatus()
+			.isOk()
+			.expectBody(Map.class)
+			.consumeWith(res -> {
+				Map<String, Object> body = res.getResponseBody();
+				assertThat(body).isNotNull();
+				Map<String, Object> headers = getMap(body, "headers");
+				assertThat(headers).isNotNull();
+				// recursive true: nested headers.Foo removed (httpbin preserves this
+				// casing)
+				assertThat(headers).doesNotContainKey("Foo");
+				assertThat(headers).containsEntry("Bar", "keep-me");
+			});
+	}
+
+	@SpringBootConfiguration
+	@EnableAutoConfiguration
+	@LoadBalancerClient(name = "httpbin", configuration = TestLoadBalancerConfig.Httpbin.class)
+	@Import(PermitAllSecurityConfiguration.class)
+	static class Config {
+
+	}
+
+}

spring-cloud-gateway-server-webmvc/src/test/resources/application-removejsonattributesshortcuttests.yml

@@ -0,0 +1,21 @@
+httpbin.base: http://${httpbin.host}:${httpbin.port}
+spring.cloud.gateway.server.webmvc:
+  function:
+    enabled: false
+  routes:
+    - id: removeJsonAttrsNoFlag
+      uri: ${httpbin.base}
+      predicates:
+        - Path=/get
+      filters:
+        - RemoveJsonAttributesResponseBody=origin,url
+    - id: removeJsonAttrsWithFlag
+      uri: ${httpbin.base}
+      predicates:
+        - Path=/post
+      filters:
+        - RemoveJsonAttributesResponseBody=Foo,true
+
+logging:
+  level:
+    org.springframework.cloud.gateway.server.mvc: INFO