Stop using using legacy locale data for Date/Time formatting tests

Commit 84714fbae9 introduced usage of the
-Djava.locale.providers=COMPAT command-line argument for javac in order
to allow our JDK 20 builds to pass by using legacy locale data.

That was done to ensure that Date/Time formats using AM/PM produced a
standard space (" ") before the "AM" or "PM" instead of a narrow
non-breaking space (NNBSP "\u202F"), which was introduced in Java 20
due to adoption of Unicode Common Locale Data Repository (CLDR-14032).

This commit removes usage of the -Djava.locale.providers=COMPAT
command-line argument and updates all affected tests to:

- Use an NNBSP before "AM" or "PM" in input text when running on Java 20
  or higher.

- Leniently match against any Unicode space character in formatted
  values containing "AM" or "PM".

See https://jdk.java.net/20/release-notes#JDK-8284840
See https://unicode-org.atlassian.net/browse/CLDR-14032
See gh-30185
Closes gh-33144

buildSrc/src/main/java/org/springframework/build/TestConventions.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2023 the original author or authors.
+ * Copyright 2002-2024 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.
@@ -63,8 +63,7 @@ class TestConventions {
 			test.systemProperty("testGroups", project.getProperties().get("testGroups"));
 		}
 		test.jvmArgs("--add-opens=java.base/java.lang=ALL-UNNAMED",
-				"--add-opens=java.base/java.util=ALL-UNNAMED",
-				"-Djava.locale.providers=COMPAT");
+				"--add-opens=java.base/java.util=ALL-UNNAMED");
 	}
 
 	private void configureTestRetryPlugin(Project project, Test test) {

spring-context/src/test/java/org/springframework/format/datetime/standard/DateTimeFormatterFactoryTests.java

@@ -78,8 +78,8 @@ class DateTimeFormatterFactoryTests {
 	void createDateTimeFormatterInOrderOfPropertyPriority() {
 		factory.setStylePattern("SS");
 		String value = applyLocale(factory.createDateTimeFormatter()).format(dateTime);
-		assertThat(value).startsWith("10/21/09");
-		assertThat(value).endsWith("12:10 PM");
+		// \p{Zs} matches any Unicode space character
+		assertThat(value).startsWith("10/21/09").matches(".+?12:10\\p{Zs}PM");
 
 		factory.setIso(ISO.DATE);
 		assertThat(applyLocale(factory.createDateTimeFormatter()).format(dateTime)).isEqualTo("2009-10-21");

spring-context/src/test/java/org/springframework/format/datetime/standard/DateTimeFormattingTests.java

@@ -42,6 +42,7 @@ import org.junit.jupiter.api.AfterEach;
 import org.junit.jupiter.api.BeforeEach;
 import org.junit.jupiter.api.Nested;
 import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.condition.EnabledForJreRange;
 import org.junit.jupiter.params.ParameterizedTest;
 import org.junit.jupiter.params.provider.ValueSource;
 
@@ -58,6 +59,8 @@ import org.springframework.validation.DataBinder;
 import org.springframework.validation.FieldError;
 
 import static org.assertj.core.api.Assertions.assertThat;
+import static org.junit.jupiter.api.condition.JRE.JAVA_19;
+import static org.junit.jupiter.api.condition.JRE.JAVA_20;
 
 /**
  * @author Keith Donald
@@ -68,6 +71,12 @@ import static org.assertj.core.api.Assertions.assertThat;
  */
 class DateTimeFormattingTests {
 
+	// JDK <= 19 requires a standard space before "AM/PM".
+	// JDK >= 20 requires a NNBSP before "AM/PM".
+	// \u202F is a narrow non-breaking space (NNBSP).
+	private static final String TIME_SEPARATOR = (Runtime.version().feature() < 20 ? " " : "\u202F");
+
+
 	private final FormattingConversionService conversionService = new FormattingConversionService();
 
 	private DataBinder binder;
@@ -210,10 +219,11 @@ class DateTimeFormattingTests {
 	@Test
 	void testBindLocalTime() {
 		MutablePropertyValues propertyValues = new MutablePropertyValues();
-		propertyValues.add("localTime", "12:00 PM");
+		propertyValues.add("localTime", "12:00%sPM".formatted(TIME_SEPARATOR));
 		binder.bind(propertyValues);
 		assertThat(binder.getBindingResult().getErrorCount()).isZero();
-		assertThat(binder.getBindingResult().getFieldValue("localTime")).isEqualTo("12:00 PM");
+		// \p{Zs} matches any Unicode space character
+		assertThat(binder.getBindingResult().getFieldValue("localTime")).asString().matches("12:00\\p{Zs}PM");
 	}
 
 	@Test
@@ -222,7 +232,8 @@ class DateTimeFormattingTests {
 		propertyValues.add("localTime", "12:00:00");
 		binder.bind(propertyValues);
 		assertThat(binder.getBindingResult().getErrorCount()).isZero();
-		assertThat(binder.getBindingResult().getFieldValue("localTime")).isEqualTo("12:00 PM");
+		// \p{Zs} matches any Unicode space character
+		assertThat(binder.getBindingResult().getFieldValue("localTime")).asString().matches("12:00\\p{Zs}PM");
 	}
 
 	@Test
@@ -231,10 +242,11 @@ class DateTimeFormattingTests {
 		registrar.setTimeStyle(FormatStyle.MEDIUM);
 		setup(registrar);
 		MutablePropertyValues propertyValues = new MutablePropertyValues();
-		propertyValues.add("localTime", "12:00:00 PM");
+		propertyValues.add("localTime", "12:00:00%sPM".formatted(TIME_SEPARATOR));
 		binder.bind(propertyValues);
 		assertThat(binder.getBindingResult().getErrorCount()).isZero();
-		assertThat(binder.getBindingResult().getFieldValue("localTime")).isEqualTo("12:00:00 PM");
+		// \p{Zs} matches any Unicode space character
+		assertThat(binder.getBindingResult().getFieldValue("localTime")).asString().matches("12:00:00\\p{Zs}PM");
 	}
 
 	@Test
@@ -252,10 +264,11 @@ class DateTimeFormattingTests {
 	@Test
 	void testBindLocalTimeAnnotated() {
 		MutablePropertyValues propertyValues = new MutablePropertyValues();
-		propertyValues.add("styleLocalTime", "12:00:00 PM");
+		propertyValues.add("styleLocalTime", "12:00:00%sPM".formatted(TIME_SEPARATOR));
 		binder.bind(propertyValues);
 		assertThat(binder.getBindingResult().getErrorCount()).isZero();
-		assertThat(binder.getBindingResult().getFieldValue("styleLocalTime")).isEqualTo("12:00:00 PM");
+		// \p{Zs} matches any Unicode space character
+		assertThat(binder.getBindingResult().getFieldValue("styleLocalTime")).asString().matches("12:00:00\\p{Zs}PM");
 	}
 
 	@Test
@@ -264,7 +277,8 @@ class DateTimeFormattingTests {
 		propertyValues.add("localTime", new GregorianCalendar(1970, 0, 0, 12, 0));
 		binder.bind(propertyValues);
 		assertThat(binder.getBindingResult().getErrorCount()).isZero();
-		assertThat(binder.getBindingResult().getFieldValue("localTime")).isEqualTo("12:00 PM");
+		// \p{Zs} matches any Unicode space character
+		assertThat(binder.getBindingResult().getFieldValue("localTime")).asString().matches("12:00\\p{Zs}PM");
 	}
 
 	@Test
@@ -274,7 +288,8 @@ class DateTimeFormattingTests {
 		binder.bind(propertyValues);
 		assertThat(binder.getBindingResult().getErrorCount()).isZero();
 		String value = binder.getBindingResult().getFieldValue("localDateTime").toString();
-		assertThat(value).startsWith("10/31/09").endsWith("12:00 PM");
+		// \p{Zs} matches any Unicode space character
+		assertThat(value).startsWith("10/31/09").matches(".+?12:00\\p{Zs}PM");
 	}
 
 	@Test
@@ -284,7 +299,8 @@ class DateTimeFormattingTests {
 		binder.bind(propertyValues);
 		assertThat(binder.getBindingResult().getErrorCount()).isZero();
 		String value = binder.getBindingResult().getFieldValue("localDateTime").toString();
-		assertThat(value).startsWith("10/31/09").endsWith("12:00 PM");
+		// \p{Zs} matches any Unicode space character
+		assertThat(value).startsWith("10/31/09").matches(".+?12:00\\p{Zs}PM");
 	}
 
 	@Test
@@ -294,7 +310,8 @@ class DateTimeFormattingTests {
 		binder.bind(propertyValues);
 		assertThat(binder.getBindingResult().getErrorCount()).isZero();
 		String value = binder.getBindingResult().getFieldValue("styleLocalDateTime").toString();
-		assertThat(value).startsWith("Oct 31, 2009").endsWith("12:00:00 PM");
+		// \p{Zs} matches any Unicode space character
+		assertThat(value).startsWith("Oct 31, 2009").matches(".+?12:00:00\\p{Zs}PM");
 	}
 
 	@Test
@@ -304,7 +321,8 @@ class DateTimeFormattingTests {
 		binder.bind(propertyValues);
 		assertThat(binder.getBindingResult().getErrorCount()).isZero();
 		String value = binder.getBindingResult().getFieldValue("localDateTime").toString();
-		assertThat(value).startsWith("10/31/09").endsWith("12:00 PM");
+		// \p{Zs} matches any Unicode space character
+		assertThat(value).startsWith("10/31/09").matches(".+?12:00\\p{Zs}PM");
 	}
 
 	@Test
@@ -317,7 +335,8 @@ class DateTimeFormattingTests {
 		binder.bind(propertyValues);
 		assertThat(binder.getBindingResult().getErrorCount()).isZero();
 		String value = binder.getBindingResult().getFieldValue("localDateTime").toString();
-		assertThat(value).startsWith("Oct 31, 2009").endsWith("12:00:00 PM");
+		// \p{Zs} matches any Unicode space character
+		assertThat(value).startsWith("Oct 31, 2009").matches(".+?12:00:00\\p{Zs}PM");
 	}
 
 	@Test
@@ -558,18 +577,32 @@ class DateTimeFormattingTests {
 			assertThat(bindingResult.getFieldValue(propertyName)).isEqualTo("2021-03-02");
 		}
 
+		@EnabledForJreRange(max = JAVA_19)
 		@ParameterizedTest(name = "input date: {0}")
-		// @ValueSource(strings = {"12:00:00\u202FPM", "12:00:00", "12:00"})
+		// JDK <= 19 requires a standard space before the "PM".
 		@ValueSource(strings = {"12:00:00 PM", "12:00:00", "12:00"})
-		void styleLocalTime(String propertyValue) {
+		void styleLocalTime_PreJDK20(String propertyValue) {
+			styleLocalTime(propertyValue);
+		}
+
+		@EnabledForJreRange(min = JAVA_20)
+		@ParameterizedTest(name = "input date: {0}")
+		// JDK >= 20 requires a NNBSP before the "PM".
+		// \u202F is a narrow non-breaking space (NNBSP).
+		@ValueSource(strings = {"12:00:00\u202FPM", "12:00:00", "12:00"})
+		void styleLocalTime_PostJDK20(String propertyValue) {
+			styleLocalTime(propertyValue);
+		}
+
+		private void styleLocalTime(String propertyValue) {
 			String propertyName = "styleLocalTimeWithFallbackPatterns";
 			MutablePropertyValues propertyValues = new MutablePropertyValues();
 			propertyValues.add(propertyName, propertyValue);
 			binder.bind(propertyValues);
 			BindingResult bindingResult = binder.getBindingResult();
 			assertThat(bindingResult.getErrorCount()).isZero();
-			// assertThat(bindingResult.getFieldValue(propertyName)).asString().matches("12:00:00\\SPM");
-			assertThat(bindingResult.getFieldValue(propertyName)).isEqualTo("12:00:00 PM");
+			// \p{Zs} matches any Unicode space character
+			assertThat(bindingResult.getFieldValue(propertyName)).asString().matches("12:00:00\\p{Zs}PM");
 		}
 
 		@ParameterizedTest(name = "input date: {0}")

spring-web/src/test/java/org/springframework/http/converter/json/GsonFactoryBeanTests.java

@@ -128,9 +128,10 @@ class GsonFactoryBeanTests {
 		cal.set(Calendar.DATE, 1);
 		Date date = cal.getTime();
 		bean.setDate(date);
+		// \p{Zs} matches any Unicode space character
 		assertThat(gson.toJson(bean))
 				.startsWith("{\"date\":\"Jan 1, 2014")
-				.endsWith("12:00:00 AM\"}");
+				.matches(".+?12:00:00\\p{Zs}AM\"}");
 	}
 
 	@Test