Port ViewResolver docs

Port documentation originally added in commit b56bd0a1

spring-boot-docs/src/main/asciidoc/howto.adoc

@@ -621,6 +621,55 @@ configuration in your hands.
 
 
 
+[[howto-customize-view-resolvers]]
+=== Customize ViewResolvers
+A `ViewResolver` is a core components of Spring MVC, translating view names in
+`@Controllers` to actual `View` implementations.  Note that `ViewResolvers` are mainly
+used in UI applications, rather than REST-style services (a `View` is not used to render
+a `@ResponseBody`). There are many implementations of `ViewResolver` to choose from, and
+Spring on its own is not opinionated about which ones you should use. Spring Boot, on the
+other hand, installs one or two for you depending on what it finds on the classpath and
+in the application context. The `DispatcherServlet` uses all the resolvers it finds in
+the application context, trying each one in turn until it gets a result, so if you are
+adding your own you have to be aware of the order and in which position your resolver is
+added.
+
+`WebMvcAutoConfiguration` adds the following `ViewResolvers` to your context:
+
+* An `InternalResourceViewResolver` with bean id ``defaultViewResolver''. This one locates
+  physical resources that can be rendered using the `DefaultServlet` (e.g. static
+  resources and JSP pages if you are using those). It applies a prefix and a suffix to the
+  view name and then looks for a physical resource with that path in the servlet context
+  (defaults are both empty, but accessible for external configuration via
+  `spring.view.prefix` and `spring.view.suffix`). It can be overridden by providing a
+  bean of the same type.
+
+* A `BeanNameViewResolver` with id ``beanNameViewResolver''. This is a useful member of the
+  view resolver chain and will pick up any beans with the same name as the `View` being
+  resolved. It can be overridden by providing a bean of the same type, but it's unlikely
+  you will need to do that.
+
+* A `ContentNegotiatingViewResolver` with id ``viewResolver'' is only added if there *are*
+  actually beans of type `View` present. This is a ``master'' resolver, delegating to all
+  the others and attempting to find a match to the ``Accept'' HTTP header sent by the
+  client. There is a useful
+  https://spring.io/blog/2013/06/03/content-negotiation-using-views[blog about `ContentNegotiatingViewResolver`]
+  that you might like to study to learn more, and also look at the source code for detail.
+  Be careful not to define your own `ViewResolver` with id ``viewResolver'' (like the
+  `ContentNegotiatingViewResolver`) otherwise, in that case, your bean will be
+  overwritten, not the other way round.
+
+* If you use Thymeleaf you will also have a `ThymeleafViewResolver` with id
+  ``thymeleafViewResolver''. It looks for resources by surrounding the view name with a
+  prefix and suffix (externalized to `spring.thymeleaf.prefix` and
+  `spring.thymeleaf.suffix`, defaults ``classpath:/templates/'' and ``.html''
+  respectively). It can be overridden by providing a bean of the same name.
+
+Checkout {sc-spring-boot-autoconfigure}/web/WebMvcAutoConfiguration.{sc-ext}[`WebMvcAutoConfiguration`]
+and {sc-spring-boot-autoconfigure}/thymeleaf/ThymeleafAutoConfiguration.{sc-ext}[`ThymeleafAutoConfiguration`]
+
+
+
 [[howto-logging]]
 == Logging