程序包 cn.taketoday.http

类 CacheControl

java.lang.Object
cn.taketoday.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 in Cache-Control: "max-age=3600"
  • Preventing cache with CacheControl cc = CacheControl.noStore() will result in Cache-Control: "no-store"
  • Advanced cases like CacheControl cc = CacheControl.maxAge(1, TimeUnit.HOURS).noTransform().cachePublic() will result in Cache-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.

CacheControl can be used to create the value for the Cache-Control header. The Cache-Control general-header field is used to specify directives for caching mechanisms in both requests and responses. Caching directives are unidirectional, meaning that a given directive in a request is not implying that the same directive is to be given in the response.

-- From Mozilla Wiki.

从以下版本开始:
2.3.7
作者:
Brian Clozel, Juergen Hoeller, Harry Yang
另请参阅:

  • 字段详细资料

    • maxAge

      @Nullable private Duration maxAge

    • noCache

      private boolean noCache

    • noStore

      private boolean noStore

    • mustRevalidate

      private boolean mustRevalidate

    • noTransform

      private boolean noTransform

    • cachePublic

      private boolean cachePublic

    • cachePrivate

      private boolean cachePrivate

    • proxyRevalidate

      private boolean proxyRevalidate

    • staleWhileRevalidate

      @Nullable private Duration staleWhileRevalidate

    • staleIfError

      @Nullable private Duration staleIfError

    • sMaxAge

      @Nullable private Duration sMaxAge

    • immutable

      private boolean immutable

  • 构造器详细资料

    • CacheControl

      protected CacheControl()
      Create an empty CacheControl instance.
      另请参阅:

  • 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 cached
      unit - the time unit of the maxAge argument
      返回:
      this, to facilitate method chaining
      另请参阅:

    • 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
      另请参阅:

    • 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:

    • 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:

    • 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:

    • 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:

    • 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:

    • 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:

    • 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:

    • 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 cached
      unit - the time unit of the sMaxAge argument
      返回:
      this, to facilitate method chaining
      另请参阅:

    • 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
      另请参阅:

    • 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 revalidated
      unit - the time unit of the staleWhileRevalidate argument
      返回:
      this, to facilitate method chaining
      另请参阅:

    • 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
      另请参阅:

    • 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 encountered
      unit - the time unit of the staleIfError argument
      返回:
      this, to facilitate method chaining
      另请参阅:

    • 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
      另请参阅:

    • immutable

      public CacheControl immutable()
      Add an "immutable" directive.

      This directive indicates that the origin server will not update the representation of that resource during the freshness lifetime of the response. Adding a max-age directive is strongly advised to enforce the actual freshness lifetime.

      返回:
      this, to facilitate method chaining
      从以下版本开始:
      4.0
      另请参阅:

    • 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

    • toHeaderValue

      private String toHeaderValue()
      Return the "Cache-Control" header value.
      返回:
      the header value (potentially empty)

    • appendDirective

      private void appendDirective(StringBuilder builder, String value)

    • toString

      public String toString()
      覆盖:
      toString 在类中 Object