类 CacheControl
- java.lang.Object
- org.springframework.http.CacheControl
public class CacheControl extends Object
A builder for creating "Cache-Control" HTTP response headers.Adding Cache-Control directives to HTTP responses can significantly improve the client experience when interacting with a web application. This builder creates opinionated "Cache-Control" headers with response directives only, with several use cases in mind.
- Caching HTTP responses with
CacheControl cc = CacheControl.maxAge(1, TimeUnit.HOURS)
will result inCache-Control: "max-age=3600"
- Preventing cache with
CacheControl cc = CacheControl.noStore()
will result inCache-Control: "no-store"
- Advanced cases like
CacheControl cc = CacheControl.maxAge(1, TimeUnit.HOURS).noTransform().cachePublic()
will result inCache-Control: "max-age=3600, no-transform, public"
Note that to be efficient, Cache-Control headers should be written along HTTP validators such as "Last-Modified" or "ETag" headers.
- 从以下版本开始:
- 4.2
- 作者:
- Brian Clozel, Juergen Hoeller
- 另请参阅:
- rfc7234 section 5.2.2, HTTP caching - Google developers reference, Mark Nottingham's cache documentation
- Caching HTTP responses with
构造器概要
构造器 限定符 构造器 说明 protected
CacheControl()
Create an empty CacheControl instance.
方法概要
所有方法 静态方法 实例方法 具体方法 修饰符和类型 方法 说明 CacheControl
cachePrivate()
Add a "private" directive.CacheControl
cachePublic()
Add a "public" directive.static CacheControl
empty()
Return an empty directive.String
getHeaderValue()
Return the "Cache-Control" header value, if any.static CacheControl
maxAge(long maxAge, TimeUnit unit)
Add a "max-age=" directive.static CacheControl
maxAge(Duration maxAge)
Add a "max-age=" directive.CacheControl
mustRevalidate()
Add a "must-revalidate" directive.static CacheControl
noCache()
Add a "no-cache" directive.static CacheControl
noStore()
Add a "no-store" directive.CacheControl
noTransform()
Add a "no-transform" directive.CacheControl
proxyRevalidate()
Add a "proxy-revalidate" directive.CacheControl
sMaxAge(long sMaxAge, TimeUnit unit)
Add an "s-maxage" directive.CacheControl
sMaxAge(Duration sMaxAge)
Add an "s-maxage" directive.CacheControl
staleIfError(long staleIfError, TimeUnit unit)
Add a "stale-if-error" directive.CacheControl
staleIfError(Duration staleIfError)
Add a "stale-if-error" directive.CacheControl
staleWhileRevalidate(long staleWhileRevalidate, TimeUnit unit)
Add a "stale-while-revalidate" directive.CacheControl
staleWhileRevalidate(Duration staleWhileRevalidate)
Add a "stale-while-revalidate" directive.String
toString()
构造器详细资料
CacheControl
protected CacheControl()
Create an empty CacheControl instance.- 另请参阅:
empty()
方法详细资料
empty
public static CacheControl empty()
Return an empty directive.This is well suited for using other optional directives without "max-age", "no-cache" or "no-store".
- 返回:
this
, to facilitate method chaining
maxAge
public static CacheControl maxAge(long maxAge, TimeUnit unit)
Add a "max-age=" directive.This directive is well suited for publicly caching resources, knowing that they won't change within the configured amount of time. Additional directives can be also used, in case resources shouldn't be cached (
cachePrivate()
) or transformed (noTransform()
) by shared caches.In order to prevent caches to reuse the cached response even when it has become stale (i.e. the "max-age" delay is passed), the "must-revalidate" directive should be set (
mustRevalidate()
- 参数:
maxAge
- the maximum time the response should be cachedunit
- the time unit of themaxAge
argument- 返回:
this
, to facilitate method chaining- 另请参阅:
maxAge(Duration)
, rfc7234 section 5.2.2.8
maxAge
public static CacheControl maxAge(Duration maxAge)
Add a "max-age=" directive.This directive is well suited for publicly caching resources, knowing that they won't change within the configured amount of time. Additional directives can be also used, in case resources shouldn't be cached (
cachePrivate()
) or transformed (noTransform()
) by shared caches.In order to prevent caches to reuse the cached response even when it has become stale (i.e. the "max-age" delay is passed), the "must-revalidate" directive should be set (
mustRevalidate()
- 参数:
maxAge
- the maximum time the response should be cached- 返回:
this
, to facilitate method chaining- 从以下版本开始:
- 5.2
- 另请参阅:
- rfc7234 section 5.2.2.8
noCache
public static CacheControl noCache()
Add a "no-cache" directive.This directive is well suited for telling caches that the response can be reused only if the client revalidates it with the server. This directive won't disable cache altogether and may result with clients sending conditional requests (with "ETag", "If-Modified-Since" headers) and the server responding with "304 - Not Modified" status.
In order to disable caching and minimize requests/responses exchanges, the
noStore()
directive should be used instead of#noCache()
.- 返回:
this
, to facilitate method chaining- 另请参阅:
- rfc7234 section 5.2.2.2
noStore
public static CacheControl noStore()
Add a "no-store" directive.This directive is well suited for preventing caches (browsers and proxies) to cache the content of responses.
- 返回:
this
, to facilitate method chaining- 另请参阅:
- rfc7234 section 5.2.2.3
mustRevalidate
public CacheControl mustRevalidate()
Add a "must-revalidate" directive.This directive indicates that once it has become stale, a cache MUST NOT use the response to satisfy subsequent requests without successful validation on the origin server.
- 返回:
this
, to facilitate method chaining- 另请参阅:
- rfc7234 section 5.2.2.1
noTransform
public CacheControl noTransform()
Add a "no-transform" directive.This directive indicates that intermediaries (caches and others) should not transform the response content. This can be useful to force caches and CDNs not to automatically gzip or optimize the response content.
- 返回:
this
, to facilitate method chaining- 另请参阅:
- rfc7234 section 5.2.2.4
cachePublic
public CacheControl cachePublic()
Add a "public" directive.This directive indicates that any cache MAY store the response, even if the response would normally be non-cacheable or cacheable only within a private cache.
- 返回:
this
, to facilitate method chaining- 另请参阅:
- rfc7234 section 5.2.2.5
cachePrivate
public CacheControl cachePrivate()
Add a "private" directive.This directive indicates that the response message is intended for a single user and MUST NOT be stored by a shared cache.
- 返回:
this
, to facilitate method chaining- 另请参阅:
- rfc7234 section 5.2.2.6
proxyRevalidate
public CacheControl proxyRevalidate()
Add a "proxy-revalidate" directive.This directive has the same meaning as the "must-revalidate" directive, except that it does not apply to private caches (i.e. browsers, HTTP clients).
- 返回:
this
, to facilitate method chaining- 另请参阅:
- rfc7234 section 5.2.2.7
sMaxAge
public CacheControl sMaxAge(long sMaxAge, TimeUnit unit)
Add an "s-maxage" directive.This directive indicates that, in shared caches, the maximum age specified by this directive overrides the maximum age specified by other directives.
- 参数:
sMaxAge
- the maximum time the response should be cachedunit
- the time unit of thesMaxAge
argument- 返回:
this
, to facilitate method chaining- 另请参阅:
sMaxAge(Duration)
, rfc7234 section 5.2.2.9
sMaxAge
public CacheControl sMaxAge(Duration sMaxAge)
Add an "s-maxage" directive.This directive indicates that, in shared caches, the maximum age specified by this directive overrides the maximum age specified by other directives.
- 参数:
sMaxAge
- the maximum time the response should be cached- 返回:
this
, to facilitate method chaining- 从以下版本开始:
- 5.2
- 另请参阅:
- rfc7234 section 5.2.2.9
staleWhileRevalidate
public CacheControl staleWhileRevalidate(long staleWhileRevalidate, TimeUnit unit)
Add a "stale-while-revalidate" directive.This directive indicates that caches MAY serve the response in which it appears after it becomes stale, up to the indicated number of seconds. If a cached response is served stale due to the presence of this extension, the cache SHOULD attempt to revalidate it while still serving stale responses (i.e. without blocking).
- 参数:
staleWhileRevalidate
- the maximum time the response should be used while being revalidatedunit
- the time unit of thestaleWhileRevalidate
argument- 返回:
this
, to facilitate method chaining- 另请参阅:
staleWhileRevalidate(Duration)
, rfc5861 section 3
staleWhileRevalidate
public CacheControl staleWhileRevalidate(Duration staleWhileRevalidate)
Add a "stale-while-revalidate" directive.This directive indicates that caches MAY serve the response in which it appears after it becomes stale, up to the indicated number of seconds. If a cached response is served stale due to the presence of this extension, the cache SHOULD attempt to revalidate it while still serving stale responses (i.e. without blocking).
- 参数:
staleWhileRevalidate
- the maximum time the response should be used while being revalidated- 返回:
this
, to facilitate method chaining- 从以下版本开始:
- 5.2
- 另请参阅:
- rfc5861 section 3
staleIfError
public CacheControl staleIfError(long staleIfError, TimeUnit unit)
Add a "stale-if-error" directive.This directive indicates that when an error is encountered, a cached stale response MAY be used to satisfy the request, regardless of other freshness information.
- 参数:
staleIfError
- the maximum time the response should be used when errors are encounteredunit
- the time unit of thestaleIfError
argument- 返回:
this
, to facilitate method chaining- 另请参阅:
staleIfError(Duration)
, rfc5861 section 4
staleIfError
public CacheControl staleIfError(Duration staleIfError)
Add a "stale-if-error" directive.This directive indicates that when an error is encountered, a cached stale response MAY be used to satisfy the request, regardless of other freshness information.
- 参数:
staleIfError
- the maximum time the response should be used when errors are encountered- 返回:
this
, to facilitate method chaining- 从以下版本开始:
- 5.2
- 另请参阅:
- rfc5861 section 4
getHeaderValue
@Nullable public String getHeaderValue()
Return the "Cache-Control" header value, if any.- 返回:
- the header value, or
null
if no directive was added