Class CorsFilter
- All Implemented Interfaces:
Filter
,FilterConfig
,Serializable
A Filter
that enable client-side cross-origin requests by implementing W3C's CORS
(Cross-Origin Resource Sharing) specification for resources. Each
HttpServletRequest
request is inspected as per specification, and appropriate response headers are added to
HttpServletResponse
.
By default, it also sets following request attributes, that help to determine the nature of the request downstream.
- cors.isCorsRequest: Flag to determine if the request is a CORS request. Set to
true
if a CORS request;false
otherwise. - cors.request.origin: The Origin URL, i.e. the URL of the page from where the request is originated.
- cors.request.type: Type of request. Possible values:
- SIMPLE: A request which is not preceded by a pre-flight request.
- ACTUAL: A request which is preceded by a pre-flight request.
- PRE_FLIGHT: A pre-flight request.
- NOT_CORS: A normal same-origin request.
- INVALID_CORS: A cross-origin request which is invalid.
- cors.request.headers: Request headers sent as 'Access-Control-Request-Headers' header, for pre-flight request.
doFilter(ServletRequest, ServletResponse, FilterChain)
and add appropriate locking so that the
doFilter()
method executes with a consistent configuration.- See Also:
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Nested Class Summary
Modifier and TypeClassDescriptionprotected static enum
Enumerates varies types of CORS requests. -
Field Summary
Modifier and TypeFieldDescriptionstatic final String
By default, following headers are supported: Origin,Accept,X-Requested-With, Content-Type, Access-Control-Request-Method, and Access-Control-Request-Headers.static final String
By default, following methods are supported: GET, POST, HEAD and OPTIONS.static final String
By default, no origins are allowed to make requests.static final String
By default, request is decorated with CORS attributes.static final String
By default, none of the headers are exposed in response.static final String
By default, time duration to cache pre-flight response is 30 mins.static final String
By default, support credentials is disabled.static final String
Boolean value, suggesting if the request is a CORS request or not.static final String
Attribute that contains the origin of the request.static final String
The prefix to a CORS request attribute.static final String
Request headers sent as 'Access-Control-Request-Headers' header, for pre-flight request.static final String
Type of CORS request, of typeCorsFilter.CORSRequestType
.static final String
Key to retrieve allowed headers fromFilterConfig
.static final String
Key to retrieve allowed methods fromFilterConfig
.static final String
Key to retrieve allowed origins fromFilterConfig
.static final String
Key to retrieve exposed headers fromFilterConfig
.static final String
Key to retrieve preflight max age fromFilterConfig
.static final String
Key to determine if request should be decorated.static final String
Key to retrieve support credentials fromFilterConfig
.static final String
The Access-Control-Request-Headers header indicates which headers will be used in the actual request as part of the preflight request.static final String
The Access-Control-Request-Method header indicates which method will be used in the actual request as part of the preflight request.static final String
The Origin header indicates where the cross-origin request or preflight request originates from.static final String
The Access-Control-Allow-Credentials header indicates whether the response to request can be exposed when the omit credentials flag is unset.static final String
The Access-Control-Allow-Headers header indicates, as part of the response to a preflight request, which header field names can be used during the actual request.static final String
The Access-Control-Allow-Methods header indicates, as part of the response to a preflight request, which methods can be used during the actual request.static final String
The Access-Control-Allow-Origin header indicates whether a resource can be shared based by returning the value of the Origin request header in the response.static final String
The Access-Control-Expose-Headers header indicates which headers are safe to expose to the API of a CORS API specificationstatic final String
The Access-Control-Max-Age header indicates how long the results of a preflight request can be cached in a preflight result cache.static final Collection
<String> Collection
of media type values for the Content-Type header that will be treated as 'simple'. -
Constructor Summary
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Method Summary
Modifier and TypeMethodDescriptionprotected CorsFilter.CORSRequestType
checkRequestType
(HttpServletRequest request) Determines the request type.protected static void
decorateCORSProperties
(HttpServletRequest request, CorsFilter.CORSRequestType corsRequestType) Decorates theHttpServletRequest
, with CORS attributes.void
doFilter
(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain filterChain) ThedoFilter
method of the Filter is called by the container each time a request/response pair is passed through the chain due to a client request for a resource at the end of the chain.Returns aSet
of headers support by resource.Returns aSet
of HTTP methods that are allowed to make requests.Returns theSet
of allowed origins that are allowed to make requests.Obtain the headers to expose.long
Returns the preflight response cache time in seconds.protected void
handlePreflightCORS
(HttpServletRequest request, HttpServletResponse response, FilterChain filterChain) Handles CORS pre-flight request.protected void
handleSimpleCORS
(HttpServletRequest request, HttpServletResponse response, FilterChain filterChain) Handles a CORS request of typeCorsFilter.CORSRequestType
.SIMPLE.void
init()
Convenience method for sub-classes to save them having to callsuper.init(config)
.boolean
Determines if any origin is allowed to make CORS request.boolean
Should CORS specific attributes be added to the request.boolean
Determines is supports credentials is enabled.protected static String
join
(Collection<String> elements, String joinSeparator) Joins elements ofSet
into a string, where each element is separated by the provided separator.Methods inherited from class jakarta.servlet.GenericFilter
getFilterConfig, getFilterName, getInitParameter, getInitParameterNames, getServletContext, init
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Field Details
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RESPONSE_HEADER_ACCESS_CONTROL_ALLOW_ORIGIN
The Access-Control-Allow-Origin header indicates whether a resource can be shared based by returning the value of the Origin request header in the response.- See Also:
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RESPONSE_HEADER_ACCESS_CONTROL_ALLOW_CREDENTIALS
The Access-Control-Allow-Credentials header indicates whether the response to request can be exposed when the omit credentials flag is unset. When part of the response to a preflight request it indicates that the actual request can include user credentials.- See Also:
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RESPONSE_HEADER_ACCESS_CONTROL_EXPOSE_HEADERS
The Access-Control-Expose-Headers header indicates which headers are safe to expose to the API of a CORS API specification- See Also:
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RESPONSE_HEADER_ACCESS_CONTROL_MAX_AGE
The Access-Control-Max-Age header indicates how long the results of a preflight request can be cached in a preflight result cache.- See Also:
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RESPONSE_HEADER_ACCESS_CONTROL_ALLOW_METHODS
The Access-Control-Allow-Methods header indicates, as part of the response to a preflight request, which methods can be used during the actual request.- See Also:
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RESPONSE_HEADER_ACCESS_CONTROL_ALLOW_HEADERS
The Access-Control-Allow-Headers header indicates, as part of the response to a preflight request, which header field names can be used during the actual request.- See Also:
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REQUEST_HEADER_ORIGIN
The Origin header indicates where the cross-origin request or preflight request originates from.- See Also:
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REQUEST_HEADER_ACCESS_CONTROL_REQUEST_METHOD
The Access-Control-Request-Method header indicates which method will be used in the actual request as part of the preflight request.- See Also:
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REQUEST_HEADER_ACCESS_CONTROL_REQUEST_HEADERS
The Access-Control-Request-Headers header indicates which headers will be used in the actual request as part of the preflight request.- See Also:
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HTTP_REQUEST_ATTRIBUTE_PREFIX
The prefix to a CORS request attribute.- See Also:
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HTTP_REQUEST_ATTRIBUTE_ORIGIN
Attribute that contains the origin of the request.- See Also:
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HTTP_REQUEST_ATTRIBUTE_IS_CORS_REQUEST
Boolean value, suggesting if the request is a CORS request or not.- See Also:
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HTTP_REQUEST_ATTRIBUTE_REQUEST_TYPE
Type of CORS request, of typeCorsFilter.CORSRequestType
.- See Also:
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HTTP_REQUEST_ATTRIBUTE_REQUEST_HEADERS
Request headers sent as 'Access-Control-Request-Headers' header, for pre-flight request.- See Also:
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SIMPLE_HTTP_REQUEST_CONTENT_TYPE_VALUES
Collection
of media type values for the Content-Type header that will be treated as 'simple'. Note media-type values are compared ignoring parameters and in a case-insensitive manner.- See Also:
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DEFAULT_ALLOWED_ORIGINS
By default, no origins are allowed to make requests.- See Also:
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DEFAULT_ALLOWED_HTTP_METHODS
By default, following methods are supported: GET, POST, HEAD and OPTIONS.- See Also:
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DEFAULT_PREFLIGHT_MAXAGE
By default, time duration to cache pre-flight response is 30 mins.- See Also:
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DEFAULT_SUPPORTS_CREDENTIALS
By default, support credentials is disabled.- See Also:
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DEFAULT_ALLOWED_HTTP_HEADERS
By default, following headers are supported: Origin,Accept,X-Requested-With, Content-Type, Access-Control-Request-Method, and Access-Control-Request-Headers.- See Also:
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DEFAULT_EXPOSED_HEADERS
By default, none of the headers are exposed in response.- See Also:
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DEFAULT_DECORATE_REQUEST
By default, request is decorated with CORS attributes.- See Also:
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PARAM_CORS_ALLOWED_ORIGINS
Key to retrieve allowed origins fromFilterConfig
.- See Also:
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PARAM_CORS_SUPPORT_CREDENTIALS
Key to retrieve support credentials fromFilterConfig
.- See Also:
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PARAM_CORS_EXPOSED_HEADERS
Key to retrieve exposed headers fromFilterConfig
.- See Also:
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PARAM_CORS_ALLOWED_HEADERS
Key to retrieve allowed headers fromFilterConfig
.- See Also:
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PARAM_CORS_ALLOWED_METHODS
Key to retrieve allowed methods fromFilterConfig
.- See Also:
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PARAM_CORS_PREFLIGHT_MAXAGE
Key to retrieve preflight max age fromFilterConfig
.- See Also:
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PARAM_CORS_REQUEST_DECORATE
Key to determine if request should be decorated.- See Also:
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Constructor Details
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CorsFilter
public CorsFilter()
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Method Details
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doFilter
public void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain filterChain) throws IOException, ServletException Description copied from interface:jakarta.servlet.Filter
ThedoFilter
method of the Filter is called by the container each time a request/response pair is passed through the chain due to a client request for a resource at the end of the chain. The FilterChain passed in to this method allows the Filter to pass on the request and response to the next entity in the chain.A typical implementation of this method would follow the following pattern:-
1. Examine the request
2. Optionally wrap the request object with a custom implementation to filter content or headers for input filtering
3. Optionally wrap the response object with a custom implementation to filter content or headers for output filtering
4. a) Either invoke the next entity in the chain using the FilterChain object (chain.doFilter()
),
4. b) or not pass on the request/response pair to the next entity in the filter chain to block the request processing
5. Directly set headers on the response after invocation of the next entity in the filter chain.- Parameters:
servletRequest
- The request to processservletResponse
- The response associated with the requestfilterChain
- Provides access to the next filter in the chain for this filter to pass the request and response to for further processing- Throws:
IOException
- if an I/O error occurs during this filter's processing of the requestServletException
- if the processing fails for any other reason
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init
Description copied from class:jakarta.servlet.GenericFilter
Convenience method for sub-classes to save them having to callsuper.init(config)
. This is a NO-OP by default.- Overrides:
init
in classGenericFilter
- Throws:
ServletException
- If an exception occurs that interrupts the Filter's normal operation
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handleSimpleCORS
protected void handleSimpleCORS(HttpServletRequest request, HttpServletResponse response, FilterChain filterChain) throws IOException, ServletException Handles a CORS request of typeCorsFilter.CORSRequestType
.SIMPLE.- Parameters:
request
- TheHttpServletRequest
object.response
- TheHttpServletResponse
object.filterChain
- TheFilterChain
object.- Throws:
IOException
- an IO error occurredServletException
- Servlet error propagation- See Also:
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handlePreflightCORS
protected void handlePreflightCORS(HttpServletRequest request, HttpServletResponse response, FilterChain filterChain) throws IOException, ServletException Handles CORS pre-flight request.- Parameters:
request
- TheHttpServletRequest
object.response
- TheHttpServletResponse
object.filterChain
- TheFilterChain
object.- Throws:
IOException
- an IO error occurredServletException
- Servlet error propagation
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decorateCORSProperties
protected static void decorateCORSProperties(HttpServletRequest request, CorsFilter.CORSRequestType corsRequestType) Decorates theHttpServletRequest
, with CORS attributes.- cors.isCorsRequest: Flag to determine if request is a CORS request. Set to
true
if CORS request;false
otherwise. - cors.request.origin: The Origin URL.
- cors.request.type: Type of request. Values:
simple
orpreflight
ornot_cors
orinvalid_cors
- cors.request.headers: Request headers sent as 'Access-Control-Request-Headers' header, for pre-flight request.
- Parameters:
request
- TheHttpServletRequest
object.corsRequestType
- TheCorsFilter.CORSRequestType
object.
- cors.isCorsRequest: Flag to determine if request is a CORS request. Set to
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join
Joins elements ofSet
into a string, where each element is separated by the provided separator. -
checkRequestType
Determines the request type.- Parameters:
request
- The HTTP Servlet request- Returns:
- the CORS type
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isAnyOriginAllowed
public boolean isAnyOriginAllowed()Determines if any origin is allowed to make CORS request.- Returns:
true
if it's enabled; false otherwise.
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getExposedHeaders
Obtain the headers to expose.- Returns:
- the headers that should be exposed by browser.
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isSupportsCredentials
public boolean isSupportsCredentials()Determines is supports credentials is enabled.- Returns:
true
if the use of credentials is supported otherwisefalse
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getPreflightMaxAge
public long getPreflightMaxAge()Returns the preflight response cache time in seconds.- Returns:
- Time to cache in seconds.
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getAllowedOrigins
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getAllowedHttpMethods
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getAllowedHttpHeaders
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isDecorateRequest
public boolean isDecorateRequest()Should CORS specific attributes be added to the request.- Returns:
true
if the request should be decorated, otherwisefalse
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