Polish contribution

See gh-27609

spring-webmvc/src/main/java/org/springframework/web/servlet/LocaleContextResolver.java

@@ -29,10 +29,12 @@ import org.springframework.lang.Nullable;
  * Extension of {@link LocaleResolver} that adds support for a rich locale context
  * (potentially including locale and time zone information).
  *
- * <p>Also provides pre-implemented versions of {@link #resolveLocale} and {@link #setLocale},
- * delegating to {@link #resolveLocaleContext} and {@link #setLocaleContext}.
+ * <p>Also provides {@code default} implementations of {@link #resolveLocale} and
+ * {@link #setLocale} which delegate to {@link #resolveLocaleContext} and
+ * {@link #setLocaleContext}, respectively.
  *
  * @author Juergen Hoeller
+ * @author Sam Brannen
  * @since 4.0
  * @see org.springframework.context.i18n.LocaleContext
  * @see org.springframework.context.i18n.TimeZoneAwareLocaleContext
@@ -77,12 +79,32 @@ public interface LocaleContextResolver extends LocaleResolver {
 	void setLocaleContext(HttpServletRequest request, @Nullable HttpServletResponse response,
 			@Nullable LocaleContext localeContext);
 
+	/**
+	 * Default implementation of {@link LocaleResolver#resolveLocale(HttpServletRequest)}
+	 * that delegates to {@link #resolveLocaleContext(HttpServletRequest)}, falling
+	 * back to {@link HttpServletRequest#getLocale()} if necessary.
+	 * @param request the request to resolve the locale for
+	 * @return the current locale (never {@code null})
+	 * @since 6.0
+	 */
 	@Override
 	default Locale resolveLocale(HttpServletRequest request) {
 		Locale locale = resolveLocaleContext(request).getLocale();
 		return (locale != null ? locale : request.getLocale());
 	}
 
+	/**
+	 * Default implementation of {@link LocaleResolver#setLocale(HttpServletRequest,
+	 * HttpServletResponse, Locale)} that delegates to
+	 * {@link #setLocaleContext(HttpServletRequest, HttpServletResponse, LocaleContext)},
+	 * using a {@link SimpleLocaleContext}.
+	 * @param request the request to be used for locale modification
+	 * @param response the response to be used for locale modification
+	 * @param locale the new locale, or {@code null} to clear the locale
+	 * @throws UnsupportedOperationException if the LocaleResolver implementation
+	 * does not support dynamic changing of the locale
+	 * @since 6.0
+	 */
 	@Override
 	default void setLocale(HttpServletRequest request, @Nullable HttpServletResponse response, @Nullable Locale locale) {
 		setLocaleContext(request, response, (locale != null ? new SimpleLocaleContext(locale) : null));

spring-webmvc/src/main/java/org/springframework/web/servlet/i18n/AbstractLocaleContextResolver.java

@@ -24,8 +24,8 @@ import org.springframework.web.servlet.LocaleContextResolver;
 /**
  * Abstract base class for {@link LocaleContextResolver} implementations.
  *
- * <p>Provides support for a {@linkplain #setDefaultLocale(Locale) default locale}
- * and a {@linkplain #setDefaultTimeZone(TimeZone) default time zone}.
+ * <p>Provides support for a {@linkplain #setDefaultLocale(java.util.Locale) default
+ * locale} and a {@linkplain #setDefaultTimeZone(TimeZone) default time zone}.
  *
  * @author Juergen Hoeller
  * @since 4.0

spring-webmvc/src/main/java/org/springframework/web/servlet/i18n/CookieLocaleResolver.java

@@ -52,6 +52,7 @@ import org.springframework.web.util.WebUtils;
  * @author Juergen Hoeller
  * @author Jean-Pierre Pawlak
  * @author Vedran Pavic
+ * @author Sam Brannen
  * @since 27.02.2003
  * @see #setDefaultLocale
  * @see #setDefaultTimeZone
@@ -98,10 +99,7 @@ public class CookieLocaleResolver extends CookieGenerator implements LocaleConte
 
 	private Function<HttpServletRequest, Locale> defaultLocaleFunction = request -> {
 		Locale defaultLocale = getDefaultLocale();
-		if (defaultLocale == null) {
-			defaultLocale = request.getLocale();
-		}
-		return defaultLocale;
+		return (defaultLocale != null ? defaultLocale : request.getLocale());
 	};
 
 	private Function<HttpServletRequest, TimeZone> defaultTimeZoneFunction = request -> getDefaultTimeZone();
@@ -199,9 +197,11 @@ public class CookieLocaleResolver extends CookieGenerator implements LocaleConte
 
 	/**
 	 * Set the function used to determine the default locale for the given request,
-	 * called if no {@link Locale} session attribute has been found.
-	 * <p>The default implementation returns the specified default locale,
-	 * if any, else falls back to the request's accept-header locale.
+	 * called if no locale cookie has been found.
+	 * <p>The default implementation returns the configured
+	 * {@linkplain #setDefaultLocale(Locale) default locale}, if any, and otherwise
+	 * falls back to the request's {@code Accept-Language} header locale or the
+	 * default locale for the server.
 	 * @param defaultLocaleFunction the function used to determine the default locale
 	 * @since 6.0
 	 * @see #setDefaultLocale
@@ -214,8 +214,8 @@ public class CookieLocaleResolver extends CookieGenerator implements LocaleConte
 
 	/**
 	 * Set the function used to determine the default time zone for the given request,
-	 * called if no {@link TimeZone} session attribute has been found.
-	 * <p>The default implementation returns the specified default time zone,
+	 * called if no locale cookie has been found.
+	 * <p>The default implementation returns the configured default time zone,
 	 * if any, or {@code null} otherwise.
 	 * @param defaultTimeZoneFunction the function used to determine the default time zone
 	 * @since 6.0
@@ -321,8 +321,8 @@ public class CookieLocaleResolver extends CookieGenerator implements LocaleConte
 		TimeZone timeZone = null;
 		if (localeContext != null) {
 			locale = localeContext.getLocale();
-			if (localeContext instanceof TimeZoneAwareLocaleContext) {
-				timeZone = ((TimeZoneAwareLocaleContext) localeContext).getTimeZone();
+			if (localeContext instanceof TimeZoneAwareLocaleContext timeZoneAwareLocaleContext) {
+				timeZone = timeZoneAwareLocaleContext.getTimeZone();
 			}
 			addCookie(response,
 					(locale != null ? toLocaleValue(locale) : "-") + (timeZone != null ? '/' + timeZone.getID() : ""));

spring-webmvc/src/main/java/org/springframework/web/servlet/i18n/SessionLocaleResolver.java

@@ -90,10 +90,7 @@ public class SessionLocaleResolver extends AbstractLocaleContextResolver {
 
 	private Function<HttpServletRequest, Locale> defaultLocaleFunction = request -> {
 		Locale defaultLocale = getDefaultLocale();
-		if (defaultLocale == null) {
-			defaultLocale = request.getLocale();
-		}
-		return defaultLocale;
+		return (defaultLocale != null ? defaultLocale : request.getLocale());
 	};
 
 	private Function<HttpServletRequest, TimeZone> defaultTimeZoneFunction = request -> getDefaultTimeZone();
@@ -121,8 +118,10 @@ public class SessionLocaleResolver extends AbstractLocaleContextResolver {
 	/**
 	 * Set the function used to determine the default locale for the given request,
 	 * called if no {@link Locale} session attribute has been found.
-	 * <p>The default implementation returns the specified default locale,
-	 * if any, else falls back to the request's accept-header locale.
+	 * <p>The default implementation returns the configured
+	 * {@linkplain #setDefaultLocale(Locale) default locale}, if any, and otherwise
+	 * falls back to the request's {@code Accept-Language} header locale or the
+	 * default locale for the server.
 	 * @param defaultLocaleFunction the function used to determine the default locale
 	 * @since 6.0
 	 * @see #setDefaultLocale
@@ -136,7 +135,7 @@ public class SessionLocaleResolver extends AbstractLocaleContextResolver {
 	/**
 	 * Set the function used to determine the default time zone for the given request,
 	 * called if no {@link TimeZone} session attribute has been found.
-	 * <p>The default implementation returns the specified default time zone,
+	 * <p>The default implementation returns the configured default time zone,
 	 * if any, or {@code null} otherwise.
 	 * @param defaultTimeZoneFunction the function used to determine the default time zone
 	 * @since 6.0
@@ -163,7 +162,7 @@ public class SessionLocaleResolver extends AbstractLocaleContextResolver {
 			public Locale getLocale() {
 				Locale locale = (Locale) WebUtils.getSessionAttribute(request, localeAttributeName);
 				if (locale == null) {
-					locale = SessionLocaleResolver.this.defaultLocaleFunction.apply(request);
+					locale = defaultLocaleFunction.apply(request);
 				}
 				return locale;
 			}
@@ -172,7 +171,7 @@ public class SessionLocaleResolver extends AbstractLocaleContextResolver {
 			public TimeZone getTimeZone() {
 				TimeZone timeZone = (TimeZone) WebUtils.getSessionAttribute(request, timeZoneAttributeName);
 				if (timeZone == null) {
-					timeZone = SessionLocaleResolver.this.defaultTimeZoneFunction.apply(request);
+					timeZone = defaultTimeZoneFunction.apply(request);
 				}
 				return timeZone;
 			}
@@ -187,8 +186,8 @@ public class SessionLocaleResolver extends AbstractLocaleContextResolver {
 		TimeZone timeZone = null;
 		if (localeContext != null) {
 			locale = localeContext.getLocale();
-			if (localeContext instanceof TimeZoneAwareLocaleContext) {
-				timeZone = ((TimeZoneAwareLocaleContext) localeContext).getTimeZone();
+			if (localeContext instanceof TimeZoneAwareLocaleContext timeZoneAwareLocaleContext) {
+				timeZone = timeZoneAwareLocaleContext.getTimeZone();
 			}
 		}
 		WebUtils.setSessionAttribute(request, this.localeAttributeName, locale);

spring-webmvc/src/main/java/org/springframework/web/servlet/support/RequestContextUtils.java

@@ -171,10 +171,10 @@ public abstract class RequestContextUtils {
 	@Nullable
 	public static TimeZone getTimeZone(HttpServletRequest request) {
 		LocaleResolver localeResolver = getLocaleResolver(request);
-		if (localeResolver instanceof LocaleContextResolver) {
-			LocaleContext localeContext = ((LocaleContextResolver) localeResolver).resolveLocaleContext(request);
-			if (localeContext instanceof TimeZoneAwareLocaleContext) {
-				return ((TimeZoneAwareLocaleContext) localeContext).getTimeZone();
+		if (localeResolver instanceof LocaleContextResolver localeContextResolver) {
+			LocaleContext localeContext = localeContextResolver.resolveLocaleContext(request);
+			if (localeContext instanceof TimeZoneAwareLocaleContext timeZoneAwareLocaleContext) {
+				return timeZoneAwareLocaleContext.getTimeZone();
 			}
 		}
 		return null;

spring-webmvc/src/test/java/org/springframework/web/servlet/i18n/CookieLocaleResolverTests.java

@@ -412,7 +412,7 @@ class CookieLocaleResolverTests {
 	}
 
 	@Test
-	void testCustomDefaultLocaleFunction() {
+	void customDefaultLocaleFunction() {
 		request.addPreferredLocale(Locale.TAIWAN);
 
 		resolver.setDefaultLocaleFunction(request -> Locale.GERMAN);
@@ -421,7 +421,7 @@ class CookieLocaleResolverTests {
 	}
 
 	@Test
-	void testCustomDefaultTimeZoneFunction() {
+	void customDefaultTimeZoneFunction() {
 		request.addPreferredLocale(Locale.TAIWAN);
 
 		resolver.setDefaultTimeZoneFunction(request -> TimeZone.getTimeZone("GMT+1"));

spring-webmvc/src/test/java/org/springframework/web/servlet/i18n/SessionLocaleResolverTests.java

@@ -98,17 +98,16 @@ class SessionLocaleResolverTests {
 	}
 
 	@Test
-	void testCustomDefaultLocaleFunction() {
+	void customDefaultLocaleFunction() {
 		request.addPreferredLocale(Locale.TAIWAN);
 
-		SessionLocaleResolver resolver = new SessionLocaleResolver();
 		resolver.setDefaultLocaleFunction(request -> Locale.GERMAN);
 
 		assertThat(resolver.resolveLocale(request)).isEqualTo(Locale.GERMAN);
 	}
 
 	@Test
-	void testCustomDefaultTimeZoneFunction() {
+	void customDefaultTimeZoneFunction() {
 		request.addPreferredLocale(Locale.TAIWAN);
 
 		resolver.setDefaultTimeZoneFunction(request -> TimeZone.getTimeZone("GMT+1"));