Deprecate support for theme

As seen in gh-28868, the support for Themes is now deprecated as of
Spring Framework 6.0 and will be removed in a future release.

Closes gh-29114

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

@@ -64,8 +64,6 @@ import org.springframework.web.servlet.mvc.ParameterizableViewController;
 import org.springframework.web.servlet.mvc.SimpleControllerHandlerAdapter;
 import org.springframework.web.servlet.support.RequestContext;
 import org.springframework.web.servlet.support.RequestContextUtils;
-import org.springframework.web.servlet.theme.SessionThemeResolver;
-import org.springframework.web.servlet.theme.ThemeChangeInterceptor;
 import org.springframework.web.servlet.view.InternalResourceViewResolver;
 import org.springframework.web.util.WebUtils;
 
@@ -79,13 +77,16 @@ public class ComplexWebApplicationContext extends StaticWebApplicationContext {
 	@SuppressWarnings("deprecation")
 	public void refresh() throws BeansException {
 		registerSingleton(DispatcherServlet.LOCALE_RESOLVER_BEAN_NAME, SessionLocaleResolver.class);
-		registerSingleton(DispatcherServlet.THEME_RESOLVER_BEAN_NAME, SessionThemeResolver.class);
+		registerSingleton(DispatcherServlet.THEME_RESOLVER_BEAN_NAME,
+				org.springframework.web.servlet.theme.SessionThemeResolver.class);
 
 		LocaleChangeInterceptor interceptor1 = new LocaleChangeInterceptor();
 		LocaleChangeInterceptor interceptor2 = new LocaleChangeInterceptor();
 		interceptor2.setParamName("locale2");
-		ThemeChangeInterceptor interceptor3 = new ThemeChangeInterceptor();
-		ThemeChangeInterceptor interceptor4 = new ThemeChangeInterceptor();
+		org.springframework.web.servlet.theme.ThemeChangeInterceptor interceptor3 =
+				new org.springframework.web.servlet.theme.ThemeChangeInterceptor();
+		org.springframework.web.servlet.theme.ThemeChangeInterceptor interceptor4 =
+				new org.springframework.web.servlet.theme.ThemeChangeInterceptor();
 		interceptor4.setParamName("theme2");
 		UserRoleAuthorizationInterceptor interceptor5 = new UserRoleAuthorizationInterceptor();
 		interceptor5.setAuthorizedRoles("role1", "role2");
@@ -126,7 +127,8 @@ public class ComplexWebApplicationContext extends StaticWebApplicationContext {
 		pvs = new MutablePropertyValues();
 		pvs.add("order", 0);
 		pvs.add("basename", "org.springframework.web.servlet.complexviews");
-		registerSingleton("viewResolver", org.springframework.web.servlet.view.ResourceBundleViewResolver.class, pvs);
+		registerSingleton("viewResolver",
+				org.springframework.web.servlet.view.ResourceBundleViewResolver.class, pvs);
 
 		pvs = new MutablePropertyValues();
 		pvs.add("suffix", ".jsp");
@@ -410,6 +412,7 @@ public class ComplexWebApplicationContext extends StaticWebApplicationContext {
 	public static class ComplexLocaleChecker implements MyHandler {
 
 		@Override
+		@SuppressWarnings("deprecation")
 		public void doSomething(HttpServletRequest request) throws ServletException, IllegalAccessException {
 			WebApplicationContext wac = RequestContextUtils.findWebApplicationContext(request);
 			if (!(wac instanceof ComplexWebApplicationContext)) {
@@ -445,7 +448,8 @@ public class ComplexWebApplicationContext extends StaticWebApplicationContext {
 			if (!TimeZone.getDefault().equals(LocaleContextHolder.getTimeZone())) {
 				throw new ServletException("Incorrect TimeZone");
 			}
-			if (!(RequestContextUtils.getThemeResolver(request) instanceof SessionThemeResolver)) {
+			if (!(RequestContextUtils.getThemeResolver(request)
+					instanceof org.springframework.web.servlet.theme.SessionThemeResolver)) {
 				throw new ServletException("Incorrect ThemeResolver");
 			}
 			if (!"theme".equals(RequestContextUtils.getThemeResolver(request).resolveThemeName(request))) {

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

@@ -42,10 +42,10 @@ import org.springframework.web.servlet.view.InternalResourceViewResolver;
  * @author Juergen Hoeller
  * @since 21.05.2003
  */
+@SuppressWarnings("deprecation")
 public class SimpleWebApplicationContext extends StaticWebApplicationContext {
 
 	@Override
-	@SuppressWarnings("deprecation")
 	public void refresh() throws BeansException {
 		registerSingleton("/locale.do", LocaleChecker.class);
 
@@ -67,7 +67,6 @@ public class SimpleWebApplicationContext extends StaticWebApplicationContext {
 	}
 
 
-	@SuppressWarnings("deprecation")
 	public static class LocaleChecker implements Controller, org.springframework.web.servlet.mvc.LastModified {
 
 		@Override

spring-webmvc/src/test/java/org/springframework/web/servlet/config/MvcNamespaceTests.java

@@ -161,6 +161,8 @@ import static org.assertj.core.api.InstanceOfAssertFactories.BOOLEAN;
  * @author Sam Brannen
  * @author Marten Deinum
  */
+
+@SuppressWarnings("deprecation")
 public class MvcNamespaceTests {
 
 	public static final String VIEWCONTROLLER_BEAN_NAME =

spring-webmvc/src/test/java/org/springframework/web/servlet/config/annotation/InterceptorRegistryTests.java

@@ -50,12 +50,14 @@ import static org.assertj.core.api.Assertions.fail;
  * @author Rossen Stoyanchev
  * @author Eko Kurniawan Khannedy
  */
+@SuppressWarnings("deprecation")
 public class InterceptorRegistryTests {
 
 	private InterceptorRegistry registry;
 
 	private final HandlerInterceptor interceptor1 = new LocaleChangeInterceptor();
 
+	@Deprecated
 	private final HandlerInterceptor interceptor2 = new ThemeChangeInterceptor();
 
 	private TestWebRequestInterceptor webInterceptor1;
@@ -177,7 +179,6 @@ public class InterceptorRegistryTests {
 	}
 
 
-	@SuppressWarnings("deprecation")
 	private List<HandlerInterceptor> getInterceptorsForPath(String lookupPath) {
 		PathMatcher pathMatcher = new AntPathMatcher();
 		List<HandlerInterceptor> result = new ArrayList<>();

spring-webmvc/src/test/java/org/springframework/web/servlet/config/annotation/WebMvcConfigurationSupportTests.java

@@ -69,7 +69,6 @@ import org.springframework.web.servlet.HandlerInterceptor;
 import org.springframework.web.servlet.HandlerMapping;
 import org.springframework.web.servlet.LocaleResolver;
 import org.springframework.web.servlet.RequestToViewNameTranslator;
-import org.springframework.web.servlet.ThemeResolver;
 import org.springframework.web.servlet.ViewResolver;
 import org.springframework.web.servlet.handler.BeanNameUrlHandlerMapping;
 import org.springframework.web.servlet.handler.ConversionServiceExposingInterceptor;
@@ -85,7 +84,6 @@ import org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandl
 import org.springframework.web.servlet.mvc.support.DefaultHandlerExceptionResolver;
 import org.springframework.web.servlet.resource.ResourceUrlProviderExposingInterceptor;
 import org.springframework.web.servlet.support.SessionFlashMapManager;
-import org.springframework.web.servlet.theme.FixedThemeResolver;
 import org.springframework.web.servlet.view.BeanNameViewResolver;
 import org.springframework.web.servlet.view.DefaultRequestToViewNameTranslator;
 import org.springframework.web.servlet.view.InternalResourceViewResolver;
@@ -335,12 +333,14 @@ public class WebMvcConfigurationSupportTests {
 	}
 
 	@Test
+	@SuppressWarnings("deprecation")
 	public void defaultThemeResolverConfiguration() {
 		ApplicationContext context = initContext(WebConfig.class);
-		ThemeResolver themeResolver = context.getBean(THEME_RESOLVER_BEAN_NAME, ThemeResolver.class);
+		org.springframework.web.servlet.ThemeResolver themeResolver =
+				context.getBean(THEME_RESOLVER_BEAN_NAME, org.springframework.web.servlet.ThemeResolver.class);
 
 		assertThat(themeResolver).isNotNull();
-		assertThat(themeResolver).isInstanceOf(FixedThemeResolver.class);
+		assertThat(themeResolver).isInstanceOf(org.springframework.web.servlet.theme.FixedThemeResolver.class);
 	}
 
 	@Test

spring-webmvc/src/test/java/org/springframework/web/servlet/tags/AbstractTagTests.java

@@ -35,6 +35,7 @@ import org.springframework.web.testfixture.servlet.MockServletContext;
  * @author Juergen Hoeller
  * @author Sam Brannen
  */
+@SuppressWarnings("deprecation")
 public abstract class AbstractTagTests {
 
 	protected MockPageContext createPageContext() {

spring-webmvc/src/test/java/org/springframework/web/servlet/tags/ThemeTagTests.java

@@ -36,6 +36,7 @@ import static org.assertj.core.api.Assertions.assertThat;
  * @author Juergen Hoeller
  * @author Alef Arendsen
  */
+@SuppressWarnings("deprecation")
 class ThemeTagTests extends AbstractTagTests {
 
 	@Test

spring-webmvc/src/test/java/org/springframework/web/servlet/theme/ThemeResolverTests.java

@@ -30,6 +30,7 @@ import static org.assertj.core.api.Assertions.assertThat;
  * @author Juergen Hoeller
  * @since 19.06.2003
  */
+@SuppressWarnings("deprecation")
 public class ThemeResolverTests {
 
 	private static final String TEST_THEME_NAME = "test.theme";

spring-webmvc/src/test/java/org/springframework/web/servlet/view/ViewResolverTests.java

@@ -64,6 +64,7 @@ import static org.assertj.core.api.Assertions.assertThatExceptionOfType;
  * @author Sam Brannen
  * @since 18.06.2003
  */
+@SuppressWarnings("deprecation")
 public class ViewResolverTests {
 
 	private final StaticWebApplicationContext wac = new StaticWebApplicationContext();

spring-webmvc/src/test/java/org/springframework/web/servlet/view/freemarker/FreeMarkerMacroTests.java

@@ -57,6 +57,7 @@ import static org.assertj.core.api.Assertions.assertThat;
  * @author Sam Brannen
  * @since 25.01.2005
  */
+@SuppressWarnings("deprecation")
 public class FreeMarkerMacroTests {
 
 	private static final String TEMPLATE_FILE = "test.ftl";