Support for BCP 47 language tags

Issue: SPR-13032

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

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2013 the original author or authors.
+ * Copyright 2002-2015 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.
@@ -81,6 +81,8 @@ public class CookieLocaleResolver extends CookieGenerator implements LocaleConte
 	public static final String DEFAULT_COOKIE_NAME = CookieLocaleResolver.class.getName() + ".LOCALE";
 
 
+	private boolean languageTagCompliant = false;
+
 	private Locale defaultLocale;
 
 	private TimeZone defaultTimeZone;
@@ -94,6 +96,30 @@ public class CookieLocaleResolver extends CookieGenerator implements LocaleConte
 		setCookieName(DEFAULT_COOKIE_NAME);
 	}
 
+
+	/**
+	 * Specify whether this resolver's cookies should be compliant with BCP 47
+	 * language tags instead of Java's legacy locale specification format.
+	 * The default is {@code false}.
+	 * <p>Note: This mode requires JDK 7 or higher. Set this flag to {@code true}
+	 * for BCP 47 compliance on JDK 7+ only.
+	 * @since 4.3
+	 * @see Locale#forLanguageTag(String)
+	 * @see Locale#toLanguageTag()
+	 */
+	public void setLanguageTagCompliant(boolean languageTagCompliant) {
+		this.languageTagCompliant = languageTagCompliant;
+	}
+
+	/**
+	 * Return whether this resolver's cookies should be compliant with BCP 47
+	 * language tags instead of Java's legacy locale specification format.
+	 * @since 4.3
+	 */
+	public boolean isLanguageTagCompliant() {
+		return this.languageTagCompliant;
+	}
+
 	/**
 	 * Set a fixed Locale that this resolver will return if no cookie found.
 	 */
@@ -111,6 +137,7 @@ public class CookieLocaleResolver extends CookieGenerator implements LocaleConte
 
 	/**
 	 * Set a fixed TimeZone that this resolver will return if no cookie found.
+	 * @since 4.0
 	 */
 	public void setDefaultTimeZone(TimeZone defaultTimeZone) {
 		this.defaultTimeZone = defaultTimeZone;
@@ -119,6 +146,7 @@ public class CookieLocaleResolver extends CookieGenerator implements LocaleConte
 	/**
 	 * Return the fixed TimeZone that this resolver will return if no cookie found,
 	 * if any.
+	 * @since 4.0
 	 */
 	protected TimeZone getDefaultTimeZone() {
 		return this.defaultTimeZone;
@@ -161,7 +189,7 @@ public class CookieLocaleResolver extends CookieGenerator implements LocaleConte
 					localePart = value.substring(0, spaceIndex);
 					timeZonePart = value.substring(spaceIndex + 1);
 				}
-				locale = (!"-".equals(localePart) ? StringUtils.parseLocaleString(localePart) : null);
+				locale = (!"-".equals(localePart) ? parseLocaleValue(localePart) : null);
 				if (timeZonePart != null) {
 					timeZone = StringUtils.parseTimeZoneString(timeZonePart);
 				}
@@ -191,7 +219,8 @@ public class CookieLocaleResolver extends CookieGenerator implements LocaleConte
 			if (localeContext instanceof TimeZoneAwareLocaleContext) {
 				timeZone = ((TimeZoneAwareLocaleContext) localeContext).getTimeZone();
 			}
-			addCookie(response, (locale != null ? locale : "-") + (timeZone != null ? ' ' + timeZone.getID() : ""));
+			addCookie(response,
+					(locale != null ? toLocaleValue(locale) : "-") + (timeZone != null ? ' ' + timeZone.getID() : ""));
 		}
 		else {
 			removeCookie(response);
@@ -203,6 +232,32 @@ public class CookieLocaleResolver extends CookieGenerator implements LocaleConte
 	}
 
 
+	/**
+	 * Parse the given locale value coming from an incoming cookie.
+	 * <p>The default implementation calls {@link StringUtils#parseLocaleString(String)}
+	 * or JDK 7's {@link Locale#forLanguageTag(String)}, depending on the
+	 * {@link #setLanguageTagCompliant "languageTagCompliant"} configuration property.
+	 * @param locale the locale value to parse
+	 * @return the corresponding {@code Locale} instance
+	 * @since 4.3
+	 */
+	protected Locale parseLocaleValue(String locale) {
+		return (isLanguageTagCompliant() ? Locale.forLanguageTag(locale) : StringUtils.parseLocaleString(locale));
+	}
+
+	/**
+	 * Render the given locale as a text value for inclusion in a cookie.
+	 * <p>The default implementation calls {@link Locale#toString()}
+	 * or JDK 7's {@link Locale#toLanguageTag()}, depending on the
+	 * {@link #setLanguageTagCompliant "languageTagCompliant"} configuration property.
+	 * @param locale the locale to stringify
+	 * @return a String representation for the given locale
+	 * @since 4.3
+	 */
+	protected String toLocaleValue(Locale locale) {
+		return (isLanguageTagCompliant() ? locale.toLanguageTag() : locale.toString());
+	}
+
 	/**
 	 * Determine the default locale for the given request,
 	 * Called if no locale cookie has been found.

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

@@ -16,6 +16,7 @@
 
 package org.springframework.web.servlet.i18n;
 
+import java.util.Locale;
 import javax.servlet.ServletException;
 import javax.servlet.http.HttpServletRequest;
 import javax.servlet.http.HttpServletResponse;
@@ -54,6 +55,8 @@ public class LocaleChangeInterceptor extends HandlerInterceptorAdapter {
 
 	private boolean ignoreInvalidLocale = false;
 
+	private boolean languageTagCompliant = false;
+
 
 	/**
 	 * Set the name of the parameter that contains a locale specification
@@ -104,6 +107,29 @@ public class LocaleChangeInterceptor extends HandlerInterceptorAdapter {
 		return this.ignoreInvalidLocale;
 	}
 
+	/**
+	 * Specify whether to parse request parameter values as BCP 47 language tags
+	 * instead of Java's legacy locale specification format.
+	 * The default is {@code false}.
+	 * <p>Note: This mode requires JDK 7 or higher. Set this flag to {@code true}
+	 * for BCP 47 compliance on JDK 7+ only.
+	 * @since 4.3
+	 * @see Locale#forLanguageTag(String)
+	 * @see Locale#toLanguageTag()
+	 */
+	public void setLanguageTagCompliant(boolean languageTagCompliant) {
+		this.languageTagCompliant = languageTagCompliant;
+	}
+
+	/**
+	 * Return whether to use BCP 47 language tags instead of Java's legacy
+	 * locale specification format.
+	 * @since 4.3
+	 */
+	public boolean isLanguageTagCompliant() {
+		return this.languageTagCompliant;
+	}
+
 
 	@Override
 	public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler)
@@ -118,7 +144,7 @@ public class LocaleChangeInterceptor extends HandlerInterceptorAdapter {
 							"No LocaleResolver found: not in a DispatcherServlet request?");
 				}
 				try {
-					localeResolver.setLocale(request, response, StringUtils.parseLocaleString(newLocale));
+					localeResolver.setLocale(request, response, parseLocaleValue(newLocale));
 				}
 				catch (IllegalArgumentException ex) {
 					if (isIgnoreInvalidLocale()) {
@@ -147,4 +173,17 @@ public class LocaleChangeInterceptor extends HandlerInterceptorAdapter {
 		return false;
 	}
 
+	/**
+	 * Parse the given locale value as coming from a request parameter.
+	 * <p>The default implementation calls {@link StringUtils#parseLocaleString(String)}
+	 * or JDK 7's {@link Locale#forLanguageTag(String)}, depending on the
+	 * {@link #setLanguageTagCompliant "languageTagCompliant"} configuration property.
+	 * @param locale the locale value to parse
+	 * @return the corresponding {@code Locale} instance
+	 * @since 4.3
+	 */
+	protected Locale parseLocaleValue(String locale) {
+		return (isLanguageTagCompliant() ? Locale.forLanguageTag(locale) : StringUtils.parseLocaleString(locale));
+	}
+
 }

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

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2013 the original author or authors.
+ * Copyright 2002-2015 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.
@@ -164,6 +164,58 @@ public class CookieLocaleResolverTests {
 		assertEquals(TimeZone.getTimeZone("GMT+1"), ((TimeZoneAwareLocaleContext) loc).getTimeZone());
 	}
 
+	@Test
+	public void testSetAndResolveLocaleWithCountry() {
+		MockHttpServletRequest request = new MockHttpServletRequest();
+		MockHttpServletResponse response = new MockHttpServletResponse();
+
+		CookieLocaleResolver resolver = new CookieLocaleResolver();
+		resolver.setLocale(request, response, new Locale("de", "AT"));
+
+		Cookie cookie = response.getCookie(CookieLocaleResolver.DEFAULT_COOKIE_NAME);
+		assertNotNull(cookie);
+		assertEquals(CookieLocaleResolver.DEFAULT_COOKIE_NAME, cookie.getName());
+		assertEquals(null, cookie.getDomain());
+		assertEquals(CookieLocaleResolver.DEFAULT_COOKIE_PATH, cookie.getPath());
+		assertFalse(cookie.getSecure());
+		assertEquals("de_AT", cookie.getValue());
+
+		request = new MockHttpServletRequest();
+		request.setCookies(cookie);
+
+		resolver = new CookieLocaleResolver();
+		Locale loc = resolver.resolveLocale(request);
+		assertEquals("de", loc.getLanguage());
+		assertEquals("AT", loc.getCountry());
+	}
+
+	@Test
+	public void testSetAndResolveLocaleWithCountryAsLanguageTag() {
+		MockHttpServletRequest request = new MockHttpServletRequest();
+		MockHttpServletResponse response = new MockHttpServletResponse();
+
+		CookieLocaleResolver resolver = new CookieLocaleResolver();
+		resolver.setLanguageTagCompliant(true);
+		resolver.setLocale(request, response, new Locale("de", "AT"));
+
+		Cookie cookie = response.getCookie(CookieLocaleResolver.DEFAULT_COOKIE_NAME);
+		assertNotNull(cookie);
+		assertEquals(CookieLocaleResolver.DEFAULT_COOKIE_NAME, cookie.getName());
+		assertEquals(null, cookie.getDomain());
+		assertEquals(CookieLocaleResolver.DEFAULT_COOKIE_PATH, cookie.getPath());
+		assertFalse(cookie.getSecure());
+		assertEquals("de-AT", cookie.getValue());
+
+		request = new MockHttpServletRequest();
+		request.setCookies(cookie);
+
+		resolver = new CookieLocaleResolver();
+		resolver.setLanguageTagCompliant(true);
+		Locale loc = resolver.resolveLocale(request);
+		assertEquals("de", loc.getLanguage());
+		assertEquals("AT", loc.getCountry());
+	}
+
 	@Test
 	public void testCustomCookie() {
 		MockHttpServletRequest request = new MockHttpServletRequest();