io.dropwizard.jersey.caching

Annotation Type CacheControl

@Documented
@Target(value=METHOD)
@Retention(value=RUNTIME)
public @interface CacheControl

An annotation which adds a constant Cache-Control header to the response produced by the annotated method.

Optional Element Summary

Optional Elements

Modifier and Type	Optional Element and Description
boolean	immutable If set, adds a Cache-Control header to the response which indicates the response is immutable and should be kept in cache for as long as possible.
boolean	isPrivate Controls the private setting of the Cache-Control header.
int	maxAge Controls the max-age setting of the Cache-Control header.
TimeUnit	maxAgeUnit The time unit of maxAge().
boolean	mustRevalidate Controls the must-revalidate setting of the Cache-Control header.
boolean	noCache Controls the no-cache setting of the Cache-Control header.
boolean	noStore Controls the no-store setting of the Cache-Control header.
boolean	noTransform Controls the no-transform setting of the Cache-Control header.
boolean	proxyRevalidate Controls the proxy-revalidate setting of the Cache-Control header.
int	sharedMaxAge Controls the s-max-age setting of the Cache-Control header.
TimeUnit	sharedMaxAgeUnit The time unit of sharedMaxAge().

Element Detail

immutable

public abstract boolean immutable

If set, adds a Cache-Control header to the response which indicates the response is immutable and should be kept in cache for as long as possible. (Technically, this corresponds to a max-age of one year.

Returns:

true if the response should be considered immutable and cached indefinitely

See Also:

maxAge()

Default:

false

isPrivate

public abstract boolean isPrivate

Controls the private setting of the Cache-Control header.

From the HTTPbis spec:

The private response directive indicates that the response message is intended for a single user and MUST NOT be stored by a shared cache. A private cache MAY store the response. If the private response directive specifies one or more field-names, this requirement is limited to the field-values associated with the listed response header fields. That is, a shared cache MUST NOT store the specified field-names(s), whereas it MAY store the remainder of the response message. Note: This usage of the word "private" only controls where the response can be stored; it cannot ensure the privacy of the message content. Also, private response directives with field-names are often handled by implementations as if an unqualified private directive was received; i.e., the special handling for the qualified form is not widely implemented.

Returns:

true if the response must not be stored by a shared cache

Default:

false

noCache

public abstract boolean noCache

Controls the no-cache setting of the Cache-Control header.

From the HTTPbis spec:

The no-cache response directive indicates that the response MUST NOT be used to satisfy a subsequent request without successful validation on the origin server. This allows an origin server to prevent a cache from using it to satisfy a request without contacting it, even by caches that have been configured to return stale responses. If the no-cache response directive specifies one or more field-names, then a cache MAY use the response to satisfy a subsequent request, subject to any other restrictions on caching. However, any header fields in the response that have the field-name(s) listed MUST NOT be sent in the response to a subsequent request without successful revalidation with the origin server. This allows an origin server to prevent the re-use of certain header fields in a response, while still allowing caching of the rest of the response. Note: Most HTTP/1.0 caches will not recognize or obey this directive. Also, no-cache response directives with field-names are often handled by implementations as if an unqualified no-cache directive was received; i.e., the special handling for the qualified form is not widely implemented.

Returns:

true if the response must not be cached

Default:

false

noStore

public abstract boolean noStore

Controls the no-store setting of the Cache-Control header.

From the HTTPbis spec:

The no-store response directive indicates that a cache MUST NOT store any part of either the immediate request or response. This directive applies to both private and shared caches. "MUST NOT store" in this context means that the cache MUST NOT intentionally store the information in non-volatile storage, and MUST make a best-effort attempt to remove the information from volatile storage as promptly as possible after forwarding it. This directive is NOT a reliable or sufficient mechanism for ensuring privacy. In particular, malicious or compromised caches might not recognize or obey this directive, and communications networks might be vulnerable to eavesdropping.

Returns:

true if the response must not be stored

Default:

false

noTransform

public abstract boolean noTransform

Controls the no-transform setting of the Cache-Control header.

From the HTTPbis spec:

The no-transform response directive indicates that an intermediary (regardless of whether it implements a cache) MUST NOT change the Content-Encoding, Content-Range or Content-Type response header fields, nor the response representation.

Returns:

true if the response must not be transformed by intermediaries

Default:

true

mustRevalidate

public abstract boolean mustRevalidate

Controls the must-revalidate setting of the Cache-Control header.

From the HTTPbis spec:

The must-revalidate response 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. The must-revalidate directive is necessary to support reliable operation for certain protocol features. In all circumstances a cache MUST obey the must-revalidate directive; in particular, if a cache cannot reach the origin server for any reason, it MUST generate a 504 (Gateway Timeout) response. The must-revalidate directive ought to be used by servers if and only if failure to validate a request on the representation could result in incorrect operation, such as a silently unexecuted financial transaction.

Returns:

true if caches must revalidate the content when it becomes stale

Default:

false

proxyRevalidate

public abstract boolean proxyRevalidate

Controls the proxy-revalidate setting of the Cache-Control header.

From the HTTPbis spec:

The proxy-revalidate response directive has the same meaning as the must-revalidate response directive, except that it does not apply to private caches.

Returns:

true if only proxies must revalidate the content when it becomes stale

Default:

false

maxAge

public abstract int maxAge

Controls the max-age setting of the Cache-Control header. The unit of this amount is determined by maxAgeUnit().

From the HTTPbis spec:

The max-age response directive indicates that the response is to be considered stale after its age is greater than the specified number of seconds.

Returns:

the number of maxAgeUnit()s for which the response should be considered fresh

See Also:

maxAgeUnit()

Default:

-1

maxAgeUnit

public abstract TimeUnit maxAgeUnit

The time unit of maxAge().

Returns:

the time unit of maxAge()

Default:

java.util.concurrent.TimeUnit.SECONDS

sharedMaxAge

public abstract int sharedMaxAge

Controls the s-max-age setting of the Cache-Control header. The unit of this amount is controlled by sharedMaxAgeUnit().

From the HTTPbis spec:

The s-maxage response directive indicates that, in shared caches, the maximum age specified by this directive overrides the maximum age specified by either the max-age directive or the Expires header field. The s-maxage directive also implies the semantics of the proxy-revalidate response directive.

Returns:

the number of sharedMaxAgeUnit()s for which the response should be considered fresh

Default:

-1

sharedMaxAgeUnit

public abstract TimeUnit sharedMaxAgeUnit

The time unit of sharedMaxAge().

Returns:

the time unit of sharedMaxAge()

Default:

java.util.concurrent.TimeUnit.SECONDS