Class WebContentGenerator
- java.lang.Object
- org.springframework.context.support.ApplicationObjectSupport
- org.springframework.web.context.support.WebApplicationObjectSupport
- org.springframework.web.servlet.support.WebContentGenerator
- All Implemented Interfaces:
Aware
,ApplicationContextAware
,ServletContextAware
- Direct Known Subclasses:
AbstractController
,AbstractHandlerMethodAdapter
,AnnotationMethodHandlerAdapter
,ResourceHttpRequestHandler
,WebContentInterceptor
public abstract class WebContentGenerator extends WebApplicationObjectSupport
Convenient superclass for any kind of web content generator, likeAbstractController
andWebContentInterceptor
. Can also be used for custom handlers that have their ownHandlerAdapter
.Supports HTTP cache control options. The usage of corresponding HTTP headers can be controlled via the
"cacheSeconds"
and"cacheControl"
properties.NOTE: As of Spring 4.2, this generator's default behavior changed when using only
setCacheSeconds(int)
, sending HTTP response headers that are in line with current browsers and proxies implementations (i.e. no HTTP 1.0 headers anymore) Reverting to the previous behavior can be easily done by using one of the newly deprecated methodssetUseExpiresHeader(boolean)
,setUseCacheControlHeader(boolean)
,setUseCacheControlNoStore(boolean)
orsetAlwaysMustRevalidate(boolean)
.- Author:
- Rod Johnson, Juergen Hoeller, Brian Clozel, Rossen Stoyanchev
- See Also:
setCacheSeconds(int)
,setCacheControl(org.springframework.http.CacheControl)
,setRequireSession(boolean)
Field Summary
Fields Modifier and Type Field Description protected static String
HEADER_CACHE_CONTROL
static String
METHOD_GET
HTTP method "GET"static String
METHOD_HEAD
HTTP method "HEAD"static String
METHOD_POST
HTTP method "POST"Fields inherited from class org.springframework.context.support.ApplicationObjectSupport
logger
Constructor Summary
Constructors Constructor Description WebContentGenerator()
Create a new WebContentGenerator which supports HTTP methods GET, HEAD and POST by default.WebContentGenerator(boolean restrictDefaultSupportedMethods)
Create a new WebContentGenerator.WebContentGenerator(String... supportedMethods)
Create a new WebContentGenerator.
Method Summary
All Methods Instance Methods Concrete Methods Deprecated Methods Modifier and Type Method Description protected void
applyCacheControl(HttpServletResponse response, CacheControl cacheControl)
Set the HTTP Cache-Control header according to the given settings.protected void
applyCacheSeconds(HttpServletResponse response, int cacheSeconds)
Apply the given cache seconds and generate corresponding HTTP headers, i.e.protected void
applyCacheSeconds(HttpServletResponse response, int cacheSeconds, boolean mustRevalidate)
Deprecated.protected void
cacheForSeconds(HttpServletResponse response, int seconds)
Deprecated.protected void
cacheForSeconds(HttpServletResponse response, int seconds, boolean mustRevalidate)
Deprecated.protected void
checkAndPrepare(HttpServletRequest request, HttpServletResponse response, boolean lastModified)
Deprecated.as of 4.2, since thelastModified
flag is effectively ignored, with a must-revalidate header only generated if explicitly configuredprotected void
checkAndPrepare(HttpServletRequest request, HttpServletResponse response, int cacheSeconds, boolean lastModified)
Deprecated.as of 4.2, since thelastModified
flag is effectively ignored, with a must-revalidate header only generated if explicitly configuredprotected void
checkRequest(HttpServletRequest request)
Check the given request for supported methods and a required session, if any.protected String
getAllowHeader()
Return the "Allow" header value to use in response to an HTTP OPTIONS request based on the configuredsupported methods
also automatically adding "OPTIONS" to the list even if not present as a supported method.CacheControl
getCacheControl()
Get theCacheControl
instance that builds the Cache-Control HTTP response header.int
getCacheSeconds()
Return the number of seconds that content is cached.String[]
getSupportedMethods()
Return the HTTP methods that this content generator supports.String[]
getVaryByRequestHeaders()
Return the configured request header names for the "Vary" response header.boolean
isAlwaysMustRevalidate()
Deprecated.as of 4.2, in favor ofgetCacheControl()
boolean
isRequireSession()
Return whether a session is required to handle requests.boolean
isUseCacheControlHeader()
Deprecated.as of 4.2, in favor ofgetCacheControl()
boolean
isUseCacheControlNoStore()
Deprecated.as of 4.2, in favor ofgetCacheControl()
boolean
isUseExpiresHeader()
Deprecated.as of 4.2, in favor ofgetCacheControl()
protected void
prepareResponse(HttpServletResponse response)
Prepare the given response according to the settings of this generator.protected void
preventCaching(HttpServletResponse response)
Deprecated.void
setAlwaysMustRevalidate(boolean mustRevalidate)
Deprecated.as of 4.2, in favor ofsetCacheControl(org.springframework.http.CacheControl)
void
setCacheControl(CacheControl cacheControl)
Set theCacheControl
instance to build the Cache-Control HTTP response header.void
setCacheSeconds(int seconds)
Cache content for the given number of seconds, by writing cache-related HTTP headers to the response: seconds== -1 (default value): no generation cache-related headers seconds== 0: "Cache-Control: no-store" will prevent caching seconds > 0: "Cache-Control: max-age=seconds" will ask to cache contentvoid
setRequireSession(boolean requireSession)
Set whether a session should be required to handle requests.void
setSupportedMethods(String... methods)
Set the HTTP methods that this content generator should support.void
setUseCacheControlHeader(boolean useCacheControlHeader)
Deprecated.as of 4.2, since going forward, the HTTP 1.1 cache-control header will be required, with the HTTP 1.0 headers disappearingvoid
setUseCacheControlNoStore(boolean useCacheControlNoStore)
Deprecated.as of 4.2, in favor ofsetCacheControl(org.springframework.http.CacheControl)
void
setUseExpiresHeader(boolean useExpiresHeader)
Deprecated.as of 4.2, since going forward, the HTTP 1.1 cache-control header will be required, with the HTTP 1.0 headers disappearingvoid
setVaryByRequestHeaders(String... varyByRequestHeaders)
Configure one or more request header names (e.g.Methods inherited from class org.springframework.web.context.support.WebApplicationObjectSupport
getServletContext, getTempDir, getWebApplicationContext, initApplicationContext, initServletContext, isContextRequired, setServletContext
Methods inherited from class org.springframework.context.support.ApplicationObjectSupport
getApplicationContext, getMessageSourceAccessor, initApplicationContext, requiredContextClass, setApplicationContext
Field Detail
METHOD_GET
public static final String METHOD_GET
HTTP method "GET"- See Also:
- Constant Field Values
METHOD_HEAD
public static final String METHOD_HEAD
HTTP method "HEAD"- See Also:
- Constant Field Values
METHOD_POST
public static final String METHOD_POST
HTTP method "POST"- See Also:
- Constant Field Values
HEADER_CACHE_CONTROL
protected static final String HEADER_CACHE_CONTROL
- See Also:
- Constant Field Values
Constructor Detail
WebContentGenerator
public WebContentGenerator()
Create a new WebContentGenerator which supports HTTP methods GET, HEAD and POST by default.
WebContentGenerator
public WebContentGenerator(boolean restrictDefaultSupportedMethods)
Create a new WebContentGenerator.- Parameters:
restrictDefaultSupportedMethods
-true
if this generator should support HTTP methods GET, HEAD and POST by default, orfalse
if it should be unrestricted
WebContentGenerator
public WebContentGenerator(String... supportedMethods)
Create a new WebContentGenerator.- Parameters:
supportedMethods
- the supported HTTP methods for this content generator
Method Detail
setSupportedMethods
public final void setSupportedMethods(String... methods)
Set the HTTP methods that this content generator should support.Default is GET, HEAD and POST for simple form controller types; unrestricted for general controllers and interceptors.
getSupportedMethods
public final String[] getSupportedMethods()
Return the HTTP methods that this content generator supports.
getAllowHeader
protected String getAllowHeader()
Return the "Allow" header value to use in response to an HTTP OPTIONS request based on the configuredsupported methods
also automatically adding "OPTIONS" to the list even if not present as a supported method. This means subclasses don't have to explicitly list "OPTIONS" as a supported method as long as HTTP OPTIONS requests are handled before making a call tocheckRequest(HttpServletRequest)
.- Since:
- 4.3
setRequireSession
public final void setRequireSession(boolean requireSession)
Set whether a session should be required to handle requests.
isRequireSession
public final boolean isRequireSession()
Return whether a session is required to handle requests.
setCacheControl
public final void setCacheControl(CacheControl cacheControl)
Set theCacheControl
instance to build the Cache-Control HTTP response header.- Since:
- 4.2
getCacheControl
public final CacheControl getCacheControl()
Get theCacheControl
instance that builds the Cache-Control HTTP response header.- Since:
- 4.2
setCacheSeconds
public final void setCacheSeconds(int seconds)
Cache content for the given number of seconds, by writing cache-related HTTP headers to the response:- seconds == -1 (default value): no generation cache-related headers
- seconds == 0: "Cache-Control: no-store" will prevent caching
- seconds > 0: "Cache-Control: max-age=seconds" will ask to cache content
For more specific needs, a custom
CacheControl
should be used.
getCacheSeconds
public final int getCacheSeconds()
Return the number of seconds that content is cached.
setVaryByRequestHeaders
public final void setVaryByRequestHeaders(String... varyByRequestHeaders)
Configure one or more request header names (e.g. "Accept-Language") to add to the "Vary" response header to inform clients that the response is subject to content negotiation and variances based on the value of the given request headers. The configured request header names are added only if not already present in the response "Vary" header.Note: This property is only supported on Servlet 3.0+ which allows checking existing response header values.
- Parameters:
varyByRequestHeaders
- one or more request header names- Since:
- 4.3
getVaryByRequestHeaders
public final String[] getVaryByRequestHeaders()
Return the configured request header names for the "Vary" response header.- Since:
- 4.3
setUseExpiresHeader
@Deprecated public final void setUseExpiresHeader(boolean useExpiresHeader)
Deprecated.as of 4.2, since going forward, the HTTP 1.1 cache-control header will be required, with the HTTP 1.0 headers disappearingSet whether to use the HTTP 1.0 expires header. Default is "false", as of 4.2.Note: Cache headers will only get applied if caching is enabled (or explicitly prevented) for the current request.
isUseExpiresHeader
@Deprecated public final boolean isUseExpiresHeader()
Deprecated.as of 4.2, in favor ofgetCacheControl()
Return whether the HTTP 1.0 expires header is used.
setUseCacheControlHeader
@Deprecated public final void setUseCacheControlHeader(boolean useCacheControlHeader)
Deprecated.as of 4.2, since going forward, the HTTP 1.1 cache-control header will be required, with the HTTP 1.0 headers disappearingSet whether to use the HTTP 1.1 cache-control header. Default is "true".Note: Cache headers will only get applied if caching is enabled (or explicitly prevented) for the current request.
isUseCacheControlHeader
@Deprecated public final boolean isUseCacheControlHeader()
Deprecated.as of 4.2, in favor ofgetCacheControl()
Return whether the HTTP 1.1 cache-control header is used.
setUseCacheControlNoStore
@Deprecated public final void setUseCacheControlNoStore(boolean useCacheControlNoStore)
Deprecated.as of 4.2, in favor ofsetCacheControl(org.springframework.http.CacheControl)
Set whether to use the HTTP 1.1 cache-control header value "no-store" when preventing caching. Default is "true".
isUseCacheControlNoStore
@Deprecated public final boolean isUseCacheControlNoStore()
Deprecated.as of 4.2, in favor ofgetCacheControl()
Return whether the HTTP 1.1 cache-control header value "no-store" is used.
setAlwaysMustRevalidate
@Deprecated public final void setAlwaysMustRevalidate(boolean mustRevalidate)
Deprecated.as of 4.2, in favor ofsetCacheControl(org.springframework.http.CacheControl)
An option to add 'must-revalidate' to every Cache-Control header. This may be useful with annotated controller methods, which can programmatically do a last-modified calculation as described inWebRequest.checkNotModified(long)
.Default is "false".
isAlwaysMustRevalidate
@Deprecated public final boolean isAlwaysMustRevalidate()
Deprecated.as of 4.2, in favor ofgetCacheControl()
Return whether 'must-revalidate' is added to every Cache-Control header.
checkRequest
protected final void checkRequest(HttpServletRequest request) throws ServletException
Check the given request for supported methods and a required session, if any.- Parameters:
request
- current HTTP request- Throws:
ServletException
- if the request cannot be handled because a check failed- Since:
- 4.2
prepareResponse
protected final void prepareResponse(HttpServletResponse response)
Prepare the given response according to the settings of this generator. Applies the number of cache seconds specified for this generator.- Parameters:
response
- current HTTP response- Since:
- 4.2
applyCacheControl
protected final void applyCacheControl(HttpServletResponse response, CacheControl cacheControl)
Set the HTTP Cache-Control header according to the given settings.- Parameters:
response
- current HTTP responsecacheControl
- the pre-configured cache control settings- Since:
- 4.2
applyCacheSeconds
protected final void applyCacheSeconds(HttpServletResponse response, int cacheSeconds)
Apply the given cache seconds and generate corresponding HTTP headers, i.e. allow caching for the given number of seconds in case of a positive value, prevent caching if given a 0 value, do nothing else. Does not tell the browser to revalidate the resource.- Parameters:
response
- current HTTP responsecacheSeconds
- positive number of seconds into the future that the response should be cacheable for, 0 to prevent caching
checkAndPrepare
@Deprecated protected final void checkAndPrepare(HttpServletRequest request, HttpServletResponse response, boolean lastModified) throws ServletException
Deprecated.as of 4.2, since thelastModified
flag is effectively ignored, with a must-revalidate header only generated if explicitly configured
checkAndPrepare
@Deprecated protected final void checkAndPrepare(HttpServletRequest request, HttpServletResponse response, int cacheSeconds, boolean lastModified) throws ServletException
Deprecated.as of 4.2, since thelastModified
flag is effectively ignored, with a must-revalidate header only generated if explicitly configured
applyCacheSeconds
@Deprecated protected final void applyCacheSeconds(HttpServletResponse response, int cacheSeconds, boolean mustRevalidate)
Deprecated.Apply the given cache seconds and generate respective HTTP headers.That is, allow caching for the given number of seconds in the case of a positive value, prevent caching if given a 0 value, else do nothing (i.e. leave caching to the client).
- Parameters:
response
- the current HTTP responsecacheSeconds
- the (positive) number of seconds into the future that the response should be cacheable for; 0 to prevent caching; and a negative value to leave caching to the client.mustRevalidate
- whether the client should revalidate the resource (typically only necessary for controllers with last-modified support)
cacheForSeconds
@Deprecated protected final void cacheForSeconds(HttpServletResponse response, int seconds)
Deprecated.Set HTTP headers to allow caching for the given number of seconds. Does not tell the browser to revalidate the resource.- Parameters:
response
- current HTTP responseseconds
- number of seconds into the future that the response should be cacheable for
cacheForSeconds
@Deprecated protected final void cacheForSeconds(HttpServletResponse response, int seconds, boolean mustRevalidate)
Deprecated.Set HTTP headers to allow caching for the given number of seconds. Tells the browser to revalidate the resource if mustRevalidate istrue
.- Parameters:
response
- the current HTTP responseseconds
- number of seconds into the future that the response should be cacheable formustRevalidate
- whether the client should revalidate the resource (typically only necessary for controllers with last-modified support)
preventCaching
@Deprecated protected final void preventCaching(HttpServletResponse response)
Deprecated.Prevent the response from being cached. Only called in HTTP 1.0 compatibility mode.See
https://www.mnot.net/cache_docs
.