Java 8: Single Map method can be used

web/src/main/java/org/springframework/security/web/savedrequest/DefaultSavedRequest.java

@@ -160,12 +160,7 @@ public class DefaultSavedRequest implements SavedRequest {
 	}
 
 	private void addHeader(String name, String value) {
-		List<String> values = headers.get(name);
-
-		if (values == null) {
-			values = new ArrayList<>();
-			headers.put(name, values);
-		}
+		List<String> values = headers.computeIfAbsent(name, k -> new ArrayList<>());
 
 		values.add(value);
 	}