Prior to this commit, Cache-Control HTTP headers could be set using
a WebContentInterceptor and configured cache mappings.
This commit adds support for cache-related HTTP headers at the controller
method level, by returning a ResponseEntity instance:
ResponseEntity.status(HttpStatus.OK)
.cacheControl(CacheControl.maxAge(1, TimeUnit.HOURS).cachePublic())
.eTag("deadb33f8badf00d")
.body(entity);
Also, this change now automatically checks the "ETag" and
"Last-Modified" headers in ResponseEntity, in order to respond HTTP
"304 - Not Modified" if necessary.
Issue: SPR-8550
This commit improves HTTP caching defaults and flexibility in
Spring MVC.
1) Better default caching headers
The `WebContentGenerator` abstract class has been updated with
better HTTP defaults for HTTP caching, in line with current
browsers and proxies implementation (wide support of HTTP1.1, etc);
depending on the `setCacheSeconds` value:
* sends "Cache-Control: max-age=xxx" for caching responses and
do not send a "must-revalidate" value by default.
* sends "Cache-Control: no-store" or "Cache-Control: no-cache"
in order to prevent caching
Other methods used to set specific header such as
`setUseExpiresHeader` or `setAlwaysMustRevalidate` are now deprecated
in favor of `setCacheControl` for better flexibility.
Using one of the deprecated methods re-enables previous HTTP caching
behavior.
This change is applied in many Handlers, since
`WebContentGenerator` is extended by `AbstractController`,
`WebContentInterceptor`, `ResourceHttpRequestHandler` and others.
2) New CacheControl builder class
This new class brings more flexibility and allows developers
to set custom HTTP caching headers.
Several strategies are provided:
* `CacheControl.maxAge(int)` for caching responses with a
"Cache-Control: max-age=xxx" header
* `CacheControl.noStore()` prevents responses from being cached
with a "Cache-Control: no-store" header
* `CacheControl.noCache()` forces caches to revalidate the cached
response before reusing it, with a "Cache-Control: no-store" header.
From that point, it is possible to chain method calls to craft a
custom CacheControl instance:
```
CacheControl cc = CacheControl.maxAge(1, TimeUnit.HOURS)
.cachePublic().noTransform();
```
3) Configuring HTTP caching in Resource Handlers
On top of the existing ways of configuring caching mechanisms,
it is now possible to use a custom `CacheControl` to serve
resources:
```
@Configuration
public class MyWebConfig extends WebMvcConfigurerAdapter {
@Override
public void addResourceHandlers(ResourceHandlerRegistry registry) {
CacheControl cc = CacheControl.maxAge(1, TimeUnit.HOURS);
registry.addResourceHandler("/resources/**)
.addResourceLocations("classpath:/resources/")
.setCacheControl(cc);
}
}
```
or
```
<mvc:resources mapping="/resources/**" location="classpath:/resources/">
<mvc:cachecontrol max-age="3600" cache-public="true"/>
</mvc:resources>
```
Issue: SPR-2779, SPR-6834, SPR-7129, SPR-9543, SPR-10464
This commit introduces support for HTTP byte ranges in the
ResourceHttpRequestHandler. This support consists of a number of
changes:
- Parsing of HTTP Range headers in HttpHeaders, using a new HttpRange
class and inner ByteRange/SuffixByteRange subclasses.
- MIME boundary generation moved from FormHttpMessageConverter to
MimeTypeUtils.
- writePartialContent() method introduced in ResourceHttpRequestHandler,
handling the byte range logic
- Additional partial content tests added to
ResourceHttpRequestHandlerTests.
Issue: SPR-10805
Revised HandlerMethod.getBeanType() impl for both web and messaging.
In addition, HandlerMethods get created with the internal BeanFactory now.
Issue: SPR-12832
FlashMap now has a single field reflecting the expiration time and
also provides accessors that can be used for serialization purposes.
Issue: SPR-12757
AbstractFlashMapManager no longer decodes the target query parameters
it needs to use to match to the request after the redirect.
Instead it stores query parameters as-is adn then relies on parsing the
encoded query string after the redirect.
Issue: SPR-12569
This commit ensures that @NumberFormat can be used as a
meta-annotation, as was already the case for @DateTimeFormat.
In addition, this commit polishes FormattingConversionServiceTests and
MvcNamespaceTests.
Issue: SPR-12743
Prior to this change, location checks for serving resources would append
`/` to the location path it didn't already have one.
This commit makes sure not to append a `/` if the provided location is
actually a file.
Issue: SPR-12747
Before this change, detection of X-Forwarded-* headers was only built
into ServletUriComponentsBuilder.
This change adds a new method for creating a UriComponentsBuilder from
an existing HttpRequest. This is equivalent to the fromUri method +
X-Forwarded-* header values.
Prior to this change, the `ResourceUrlProvider.getForLookupPath` method
would try to match handlers using the keySet order in the
handlerMappings Map. In case of several matches, the handler used for
the return value could vary, since the registration order in the
handlerMappings can't be guaranteed in the configuration.
This commit now collects all matching handlers and sort them using a
`PatternComparator`, in order to try each handler from the most specific
mapping to the least.
Issue: SPR-12647
This commit adds ResponseBodyEmitter and SseEmitter (and also
ResponseEntity<ResponseBodyEmitter> and ResponseEntity<SseEmitter>) as
new return value types supported on @RequestMapping controller methods.
See Javadoc on respective types for more details.
Issue: SPR-12212
Prior to this change, the ResourceUrlProvider would listen to
ContextRefreshedEvents and autodetect resource handlers each time. This
can cause issues when multiple contexts are involved and the last one
has no resource handler, thus clearing the previously detected ones.
This commit disables resource handlers auto-detection once some have
been detected with a refreshed context.
Issue: SPR-12592
Prior to this change, location paths used for resource handling would
not allow "non-cleaned, relative paths" such as
`file://home/user/static/../static/`. When checking if the resolved
resource's path starts with the location path, a mismatch would happen
when comparing for example:
* the location `file://home/user/static/../static/`
* and the resource `file://home/user/static/resource.txt`
This commit cleans the location path before comparing it to the resource
path.
Issue: SPR-12624
This commit allows the use of "protcol relative URLs" (i.e. URLs without
scheme, starting with `//`), often used to serve resources automatically
from https or http with third party domains.
This syntax is allowed by RFC 3986.
Issue: SPR-12632
This commit fixes the default value for the contextRelative attribute of
a RedirectView, when this view is registered via a
RedirectViewController in XML. The value is set to true.
Note that the default value for this is correctly documented in
spring-mvc-4.1.xsd. Also, the documentation and implementation for its
javadoc counterpart also enforces true as a default value.
Issue: SPR-12607