diff --git a/spring-cloud-gateway-server/src/main/java/org/springframework/cloud/gateway/filter/headers/HttpHeadersFilter.java b/spring-cloud-gateway-server/src/main/java/org/springframework/cloud/gateway/filter/headers/HttpHeadersFilter.java
index 921b4d50..2859eca5 100644
--- a/spring-cloud-gateway-server/src/main/java/org/springframework/cloud/gateway/filter/headers/HttpHeadersFilter.java
+++ b/spring-cloud-gateway-server/src/main/java/org/springframework/cloud/gateway/filter/headers/HttpHeadersFilter.java
@@ -58,7 +58,15 @@ public interface HttpHeadersFilter {
 
 	enum Type {
 
-		REQUEST, RESPONSE
+		/**
+		 * Filter for request headers.
+		 */
+		REQUEST,
+
+		/**
+		 * Filter for response headers.
+		 */
+		RESPONSE
 
 	}
 
diff --git a/spring-cloud-gateway-server/src/main/java/org/springframework/cloud/gateway/support/ShortcutConfigurable.java b/spring-cloud-gateway-server/src/main/java/org/springframework/cloud/gateway/support/ShortcutConfigurable.java
index 43456533..6629f363 100644
--- a/spring-cloud-gateway-server/src/main/java/org/springframework/cloud/gateway/support/ShortcutConfigurable.java
+++ b/spring-cloud-gateway-server/src/main/java/org/springframework/cloud/gateway/support/ShortcutConfigurable.java
@@ -83,6 +83,9 @@ public interface ShortcutConfigurable {
 
 	enum ShortcutType {
 
+		/**
+		 * Default shortcut type.
+		 */
 		DEFAULT {
 			@Override
 			public Map<String, Object> normalize(Map<String, String> args, ShortcutConfigurable shortcutConf,
@@ -100,6 +103,9 @@ public interface ShortcutConfigurable {
 			}
 		},
 
+		/**
+		 * List shortcut type.
+		 */
 		GATHER_LIST {
 			@Override
 			public Map<String, Object> normalize(Map<String, String> args, ShortcutConfigurable shortcutConf,
@@ -116,7 +122,9 @@ public interface ShortcutConfigurable {
 			}
 		},
 
-		// list is all elements except last which is a boolean flag
+		/**
+		 * List is all elements except last which is a boolean flag.
+		 */
 		GATHER_LIST_TAIL_FLAG {
 			@Override
 			public Map<String, Object> normalize(Map<String, String> args, ShortcutConfigurable shortcutConf,