Auto-configure templated welcome page

See gh-10545

spring-boot-project/spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/web/servlet/WebMvcAutoConfiguration.java

@@ -48,6 +48,7 @@ import org.springframework.boot.autoconfigure.condition.ConditionalOnProperty;
 import org.springframework.boot.autoconfigure.condition.ConditionalOnWebApplication;
 import org.springframework.boot.autoconfigure.condition.ConditionalOnWebApplication.Type;
 import org.springframework.boot.autoconfigure.http.HttpMessageConverters;
+import org.springframework.boot.autoconfigure.template.TemplateAvailabilityProviders;
 import org.springframework.boot.autoconfigure.validation.ValidationAutoConfiguration;
 import org.springframework.boot.autoconfigure.validation.ValidatorAdapter;
 import org.springframework.boot.autoconfigure.web.ConditionalOnEnabledResourceChain;
@@ -57,6 +58,7 @@ import org.springframework.boot.context.properties.EnableConfigurationProperties
 import org.springframework.boot.web.servlet.filter.OrderedHiddenHttpMethodFilter;
 import org.springframework.boot.web.servlet.filter.OrderedHttpPutFormContentFilter;
 import org.springframework.boot.web.servlet.filter.OrderedRequestContextFilter;
+import org.springframework.context.ApplicationContext;
 import org.springframework.context.ResourceLoaderAware;
 import org.springframework.context.annotation.Bean;
 import org.springframework.context.annotation.Configuration;
@@ -130,6 +132,7 @@ import org.springframework.web.servlet.view.InternalResourceViewResolver;
  * @author Eddú Meléndez
  * @author Stephane Nicoll
  * @author Kristine Jetzke
+ * @author Bruce Brouwer
  */
 @Configuration
 @ConditionalOnWebApplication(type = Type.SERVLET)
@@ -330,8 +333,11 @@ public class WebMvcAutoConfiguration {
 		}
 
 		@Bean
-		public WelcomePageHandlerMapping welcomePageHandlerMapping() {
-			return new WelcomePageHandlerMapping(getWelcomePage(),
+		public WelcomePageHandlerMapping welcomePageHandlerMapping(
+				ApplicationContext applicationContext) {
+			return new WelcomePageHandlerMapping(
+					new TemplateAvailabilityProviders(applicationContext),
+					applicationContext, getWelcomePage(),
 					this.mvcProperties.getStaticPathPattern());
 		}
 

spring-boot-project/spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/web/servlet/WelcomePageHandlerMapping.java

@@ -24,6 +24,8 @@ import javax.servlet.http.HttpServletRequest;
 import org.apache.commons.logging.Log;
 import org.apache.commons.logging.LogFactory;
 
+import org.springframework.boot.autoconfigure.template.TemplateAvailabilityProviders;
+import org.springframework.context.ApplicationContext;
 import org.springframework.core.io.Resource;
 import org.springframework.http.HttpHeaders;
 import org.springframework.http.MediaType;
@@ -37,19 +39,37 @@ import org.springframework.web.servlet.mvc.ParameterizableViewController;
  * static page is preferred.
  *
  * @author Andy Wilkinson
+ * @author Bruce Brouwer
  */
 final class WelcomePageHandlerMapping extends AbstractUrlHandlerMapping {
 
 	private static final Log logger = LogFactory.getLog(WelcomePageHandlerMapping.class);
 
-	WelcomePageHandlerMapping(Optional<Resource> welcomePage, String staticPathPattern) {
-		if (welcomePage.isPresent() && "/**".equals(staticPathPattern)) {
-			logger.info("Adding welcome page: " + welcomePage.get());
-			ParameterizableViewController controller = new ParameterizableViewController();
-			controller.setViewName("forward:index.html");
-			setRootHandler(controller);
-			setOrder(0);
+	WelcomePageHandlerMapping(TemplateAvailabilityProviders templateAvailabilityProviders,
+			ApplicationContext applicationContext, Optional<Resource> welcomePage,
+			String staticPathPattern) {
+		if (welcomeTemplateExists(templateAvailabilityProviders, applicationContext)) {
+			logger.info("Adding welcome page template: index");
+			setRootViewName("index");
 		}
+		else if (welcomePage.isPresent() && "/**".equals(staticPathPattern)) {
+			logger.info("Adding welcome page: " + welcomePage);
+			setRootViewName("forward:index.html");
+		}
+	}
+
+	private boolean welcomeTemplateExists(
+			TemplateAvailabilityProviders templateAvailabilityProviders,
+			ApplicationContext applicationContext) {
+		return templateAvailabilityProviders.getProvider("index",
+				applicationContext) != null;
+	}
+
+	private void setRootViewName(final String viewName) {
+		ParameterizableViewController controller = new ParameterizableViewController();
+		controller.setViewName(viewName);
+		setRootHandler(controller);
+		setOrder(0);
 	}
 
 	@Override