Clarify CompositePropertySource behavior for EnumerablePropertySource contract

jhoeller · jhoeller · commit cbb94193fe9f · 2025-05-13T16:57:06.000+02:00
Closes gh-34886 (cherry picked from commit 6a94444)
diff --git a/spring-core/src/main/java/org/springframework/core/env/CompositePropertySource.java b/spring-core/src/main/java/org/springframework/core/env/CompositePropertySource.java
@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2023 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.
@@ -33,7 +33,10 @@
  *
  * <p>As of Spring 4.1.2, this class extends {@link EnumerablePropertySource} instead
  * of plain {@link PropertySource}, exposing {@link #getPropertyNames()} based on the
- * accumulated property names from all contained sources (as far as possible).
+ * accumulated property names from all contained sources - and failing with an
+ * {@code IllegalStateException} against any non-{@code EnumerablePropertySource}.
+ * <b>When used through the {@code EnumerablePropertySource} contract, all contained
+ * sources are expected to be of type {@code EnumerablePropertySource} as well.</b>
  *
  * @author Chris Beams
  * @author Juergen Hoeller

Original file line number	Diff line number	Diff line change
`@@ -1,5 +1,5 @@`
`1`	`1`	`/*`
`2`		`- * Copyright 2002-2023 the original author or authors.`
	`2`	`+ * Copyright 2002-2025 the original author or authors.`
`3`	`3`	`*`
`4`	`4`	`* Licensed under the Apache License, Version 2.0 (the "License");`
`5`	`5`	`* you may not use this file except in compliance with the License.`
`@@ -33,7 +33,10 @@`
`33`	`33`	`*`
`34`	`34`	`* <p>As of Spring 4.1.2, this class extends {@link EnumerablePropertySource} instead`
`35`	`35`	`* of plain {@link PropertySource}, exposing {@link #getPropertyNames()} based on the`
`36`		`- * accumulated property names from all contained sources (as far as possible).`
	`36`	`+ * accumulated property names from all contained sources - and failing with an`
	`37`	`+ * {@code IllegalStateException} against any non-{@code EnumerablePropertySource}.`
	`38`	`+ * <b>When used through the {@code EnumerablePropertySource} contract, all contained`
	`39`	`+ * sources are expected to be of type {@code EnumerablePropertySource} as well.</b>`
`37`	`40`	`*`
`38`	`41`	`* @author Chris Beams`
`39`	`42`	`* @author Juergen Hoeller`