Move "Customize the whitelabel Error Page" into Spring MVC howto

Closes gh-41624

Author: mhalbritter

spring-boot-project/spring-boot-docs/src/docs/antora/modules/ROOT/pages/redirect.adoc

@@ -329,7 +329,6 @@
 * xref:gradle-plugin:running.adoc#running-your-application.using-a-test-main-class[gradle-plugin#running-your-application.using-a-test-main-class]
 * xref:how-to:actuator.adoc#howto.actuator[#howto.actuator]
 * xref:how-to:actuator.adoc#howto.actuator.change-http-port-or-address[#howto.actuator.change-http-port-or-address]
-* xref:how-to:actuator.adoc#howto.actuator.customize-whitelabel-error-page[#howto.actuator.customize-whitelabel-error-page]
 * xref:how-to:actuator.adoc#howto.actuator.customizing-sanitization[#howto.actuator.customizing-sanitization]
 * xref:how-to:actuator.adoc#howto.actuator.map-health-indicators-to-metrics[#howto.actuator.map-health-indicators-to-metrics]
 * xref:how-to:aot.adoc#howto.aot[#howto.aot]
@@ -435,6 +434,7 @@
 * xref:how-to:spring-mvc.adoc#howto.spring-mvc.customize-jackson-objectmapper[#howto.spring-mvc.customize-jackson-objectmapper]
 * xref:how-to:spring-mvc.adoc#howto.spring-mvc.customize-responsebody-rendering[#howto.spring-mvc.customize-responsebody-rendering]
 * xref:how-to:spring-mvc.adoc#howto.spring-mvc.customize-view-resolvers[#howto.spring-mvc.customize-view-resolvers]
+* xref:how-to:spring-mvc.adoc#howto.spring-mvc.customize-whitelabel-error-page[#howto.actuator.customize-whitelabel-error-page]
 * xref:how-to:spring-mvc.adoc#howto.spring-mvc.multipart-file-uploads[#howto.spring-mvc.multipart-file-uploads]
 * xref:how-to:spring-mvc.adoc#howto.spring-mvc.switch-off-default-configuration[#howto.spring-mvc.switch-off-default-configuration]
 * xref:how-to:spring-mvc.adoc#howto.spring-mvc.switch-off-dispatcherservlet[#howto.spring-mvc.switch-off-dispatcherservlet]

spring-boot-project/spring-boot-docs/src/docs/antora/modules/how-to/pages/actuator.adoc

@@ -17,26 +17,6 @@ For more detail, see the javadoc:org.springframework.boot.actuate.autoconfigure.
 
 
 
-[[howto.actuator.customize-whitelabel-error-page]]
-== Customize the '`whitelabel`' Error Page
-
-Spring Boot installs a '`whitelabel`' error page that you see in a browser client if you encounter a server error (machine clients consuming JSON and other media types should see a sensible response with the right error code).
-
-NOTE: Set `server.error.whitelabel.enabled=false` to switch the default error page off.
-Doing so restores the default of the servlet container that you are using.
-Note that Spring Boot still tries to resolve the error view, so you should probably add your own error page rather than disabling it completely.
-
-Overriding the error page with your own depends on the templating technology that you use.
-For example, if you use Thymeleaf, you can add an `error.html` template.
-If you use FreeMarker, you can add an `error.ftlh` template.
-In general, you need a `View` that resolves with a name of `error` or a `@Controller` that handles the `/error` path.
-Unless you replaced some of the default configuration, you should find a `BeanNameViewResolver` in your `ApplicationContext`, so a `@Bean` named `error` would be one way of doing that.
-See {code-spring-boot-autoconfigure-src}/web/servlet/error/ErrorMvcAutoConfiguration.java[`ErrorMvcAutoConfiguration`] for more options.
-
-See also the section on xref:reference:web/servlet.adoc#web.servlet.spring-mvc.error-handling[] for details of how to register handlers in the servlet container.
-
-
-
 [[howto.actuator.customizing-sanitization]]
 == Customizing Sanitization
 

spring-boot-project/spring-boot-docs/src/docs/antora/modules/how-to/pages/spring-mvc.adoc

@@ -240,3 +240,23 @@ For more detail, see the following sections:
 * {code-spring-boot-autoconfigure-src}/thymeleaf/ThymeleafAutoConfiguration.java[`ThymeleafAutoConfiguration`]
 * {code-spring-boot-autoconfigure-src}/freemarker/FreeMarkerAutoConfiguration.java[`FreeMarkerAutoConfiguration`]
 * {code-spring-boot-autoconfigure-src}/groovy/template/GroovyTemplateAutoConfiguration.java[`GroovyTemplateAutoConfiguration`]
+
+
+
+[[howto.spring-mvc.customize-whitelabel-error-page]]
+== Customize the '`whitelabel`' Error Page
+
+Spring Boot installs a '`whitelabel`' error page that you see in a browser client if you encounter a server error (machine clients consuming JSON and other media types should see a sensible response with the right error code).
+
+NOTE: Set `server.error.whitelabel.enabled=false` to switch the default error page off.
+Doing so restores the default of the servlet container that you are using.
+Note that Spring Boot still tries to resolve the error view, so you should probably add your own error page rather than disabling it completely.
+
+Overriding the error page with your own depends on the templating technology that you use.
+For example, if you use Thymeleaf, you can add an `error.html` template.
+If you use FreeMarker, you can add an `error.ftlh` template.
+In general, you need a `View` that resolves with a name of `error` or a `@Controller` that handles the `/error` path.
+Unless you replaced some of the default configuration, you should find a `BeanNameViewResolver` in your `ApplicationContext`, so a `@Bean` named `error` would be one way of doing that.
+See {code-spring-boot-autoconfigure-src}/web/servlet/error/ErrorMvcAutoConfiguration.java[`ErrorMvcAutoConfiguration`] for more options.
+
+See also the section on xref:reference:web/servlet.adoc#web.servlet.spring-mvc.error-handling[] for details of how to register handlers in the servlet container.