Merge pull request #27887 from dreis2211

* pr/27887:
  Polish "Fix tests on non English systems"
  Fix tests on non English systems

Closes gh-27887

spring-boot-project/spring-boot/src/test/java/org/springframework/boot/validation/MessageSourceMessageInterpolatorIntegrationTests.java

@@ -20,6 +20,7 @@ import java.util.ArrayList;
 import java.util.List;
 import java.util.Locale;
 import java.util.Set;
+import java.util.function.Supplier;
 
 import javax.validation.ConstraintViolation;
 import javax.validation.Validator;
@@ -41,8 +42,6 @@ import static org.assertj.core.api.Assertions.assertThatThrownBy;
  */
 class MessageSourceMessageInterpolatorIntegrationTests {
 
-	private final Validator validator = buildValidator();
-
 	@NotNull
 	private String defaultMessage;
 
@@ -117,12 +116,15 @@ class MessageSourceMessageInterpolatorIntegrationTests {
 	}
 
 	private List<String> validate(String property) {
-		List<String> messages = new ArrayList<>();
-		Set<ConstraintViolation<Object>> constraints = this.validator.validateProperty(this, property);
-		for (ConstraintViolation<Object> constraint : constraints) {
-			messages.add(constraint.getMessage());
-		}
-		return messages;
+		return withEnglishLocale(() -> {
+			Validator validator = buildValidator();
+			List<String> messages = new ArrayList<>();
+			Set<ConstraintViolation<Object>> constraints = validator.validateProperty(this, property);
+			for (ConstraintViolation<Object> constraint : constraints) {
+				messages.add(constraint.getMessage());
+			}
+			return messages;
+		});
 	}
 
 	private static Validator buildValidator() {
@@ -140,4 +142,15 @@ class MessageSourceMessageInterpolatorIntegrationTests {
 		}
 	}
 
+	private static <T> T withEnglishLocale(Supplier<T> supplier) {
+		Locale defaultLocale = Locale.getDefault();
+		try {
+			Locale.setDefault(Locale.ENGLISH);
+			return supplier.get();
+		}
+		finally {
+			Locale.setDefault(defaultLocale);
+		}
+	}
+
 }