Polishing in ExtendedServletRequestDataBinder

Author: rstoyanchev

spring-context/src/main/java/org/springframework/validation/DataBinder.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2024 the original author or authors.
+ * Copyright 2002-2025 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.
@@ -1412,6 +1412,9 @@ public interface ValueResolver {
 
 		/**
 		 * Return the names of all property values.
+		 * <p>Useful for proactive checks whether there are property values nested
+		 * further below the path for a constructor arg. If not then the
+		 * constructor arg can be considered missing and not to be instantiated.
 		 * @since 6.1.2
 		 */
 		Set<String> getNames();

spring-webmvc/src/main/java/org/springframework/web/servlet/mvc/method/annotation/ExtendedServletRequestDataBinder.java

@@ -125,7 +125,7 @@ protected void addBindValues(MutablePropertyValues mpvs, ServletRequest request)
 				String name = names.nextElement();
 				Object value = getHeaderValue(httpRequest, name);
 				if (value != null) {
-					name = StringUtils.uncapitalize(name.replace("-", ""));
+					name = normalizeHeaderName(name);
 					addValueIfNotPresent(mpvs, "Header", name, value);
 				}
 			}
@@ -173,6 +173,10 @@ private Object getHeaderValue(HttpServletRequest request, String name) {
 		return values;
 	}
 
+	private static String normalizeHeaderName(String name) {
+		return StringUtils.uncapitalize(name.replace("-", ""));
+	}
+
 
 	/**
 	 * Resolver of values that looks up URI path variables.
@@ -209,8 +213,10 @@ protected Set<String> initParameterNames(ServletRequest request) {
 			if (request instanceof HttpServletRequest httpServletRequest) {
 				Enumeration<String> enumeration = httpServletRequest.getHeaderNames();
 				while (enumeration.hasMoreElements()) {
-					String headerName = enumeration.nextElement();
-					set.add(headerName.replaceAll("-", ""));
+					String name = enumeration.nextElement();
+					if (headerPredicate.test(name)) {
+						set.add(normalizeHeaderName(name));
+					}
 				}
 			}
 			return set;

spring-webmvc/src/test/java/org/springframework/web/servlet/mvc/method/annotation/ExtendedServletRequestDataBinderTests.java

@@ -119,6 +119,23 @@ void filteredHeaders(String headerName) {
 		assertThat(mpvs).isEmpty();
 	}
 
+	@Test
+	void headerPredicateWithConstructorArgs() {
+		ExtendedServletRequestDataBinder binder = new ExtendedServletRequestDataBinder(null);
+		binder.addHeaderPredicate(name -> !name.equalsIgnoreCase("Some-Int-Array"));
+		binder.setTargetType(ResolvableType.forClass(DataBean.class));
+		binder.setNameResolver(new BindParamNameResolver());
+
+		request.addHeader("Some-Int-Array", "1");
+		request.addHeader("Some-Int-Array", "2");
+
+		binder.construct(request);
+
+		DataBean bean = (DataBean) binder.getTarget();
+
+		assertThat(bean.someIntArray()).isNull();
+	}
+
 	@Test
 	void headerPredicate() {
 		TestBinder binder = new TestBinder();