Class CorsFilter
- java.lang.Object
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- jakarta.servlet.GenericFilter
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- org.apache.catalina.filters.CorsFilter
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- All Implemented Interfaces:
Filter
,FilterConfig
,Serializable
public class CorsFilter extends GenericFilter
A
Filter
that enable client-side cross-origin requests by implementing W3C's CORS (Cross-Origin Resource Sharing) specification for resources. EachHttpServletRequest
request is inspected as per specification, and appropriate response headers are added toHttpServletResponse
.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 thedoFilter()
method executes with a consistent configuration.- See Also:
- CORS specification, Serialized Form
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Nested Class Summary
Nested Classes Modifier and Type Class Description protected static class
CorsFilter.CORSRequestType
Enumerates varies types of CORS requests.
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Field Summary
Fields Modifier and Type Field Description static String
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.static String
DEFAULT_ALLOWED_HTTP_METHODS
By default, following methods are supported: GET, POST, HEAD and OPTIONS.static String
DEFAULT_ALLOWED_ORIGINS
By default, no origins are allowed to make requests.static String
DEFAULT_DECORATE_REQUEST
By default, request is decorated with CORS attributes.static String
DEFAULT_EXPOSED_HEADERS
By default, none of the headers are exposed in response.static String
DEFAULT_PREFLIGHT_MAXAGE
By default, time duration to cache pre-flight response is 30 mins.static String
DEFAULT_SUPPORTS_CREDENTIALS
By default, support credentials is disabled.static String
HTTP_REQUEST_ATTRIBUTE_IS_CORS_REQUEST
Boolean value, suggesting if the request is a CORS request or not.static String
HTTP_REQUEST_ATTRIBUTE_ORIGIN
Attribute that contains the origin of the request.static String
HTTP_REQUEST_ATTRIBUTE_PREFIX
The prefix to a CORS request attribute.static String
HTTP_REQUEST_ATTRIBUTE_REQUEST_HEADERS
Request headers sent as 'Access-Control-Request-Headers' header, for pre-flight request.static String
HTTP_REQUEST_ATTRIBUTE_REQUEST_TYPE
Type of CORS request, of typeCorsFilter.CORSRequestType
.static String
PARAM_CORS_ALLOWED_HEADERS
Key to retrieve allowed headers fromFilterConfig
.static String
PARAM_CORS_ALLOWED_METHODS
Key to retrieve allowed methods fromFilterConfig
.static String
PARAM_CORS_ALLOWED_ORIGINS
Key to retrieve allowed origins fromFilterConfig
.static String
PARAM_CORS_EXPOSED_HEADERS
Key to retrieve exposed headers fromFilterConfig
.static String
PARAM_CORS_PREFLIGHT_MAXAGE
Key to retrieve preflight max age fromFilterConfig
.static String
PARAM_CORS_REQUEST_DECORATE
Key to determine if request should be decorated.static String
PARAM_CORS_SUPPORT_CREDENTIALS
Key to retrieve support credentials fromFilterConfig
.static String
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.static String
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.static String
REQUEST_HEADER_ORIGIN
The Origin header indicates where the cross-origin request or preflight request originates from.static String
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.static String
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.static String
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.static String
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.static String
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 specificationstatic String
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.static Collection<String>
SIMPLE_HTTP_REQUEST_CONTENT_TYPE_VALUES
Collection
of media type values for the Content-Type header that will be treated as 'simple'.
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Constructor Summary
Constructors Constructor Description CorsFilter()
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Method Summary
All Methods Static Methods Instance Methods Concrete Methods Modifier and Type Method Description protected 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.Collection<String>
getAllowedHttpHeaders()
Returns aSet
of headers support by resource.Collection<String>
getAllowedHttpMethods()
Returns aSet
of HTTP methods that are allowed to make requests.Collection<String>
getAllowedOrigins()
Returns theSet
of allowed origins that are allowed to make requests.Collection<String>
getExposedHeaders()
Obtain the headers to expose.long
getPreflightMaxAge()
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
isAnyOriginAllowed()
Determines if any origin is allowed to make CORS request.boolean
isDecorateRequest()
Should CORS specific attributes be added to the request.boolean
isSupportsCredentials()
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 Detail
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RESPONSE_HEADER_ACCESS_CONTROL_ALLOW_ORIGIN
public static final String 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:
- Constant Field Values
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RESPONSE_HEADER_ACCESS_CONTROL_ALLOW_CREDENTIALS
public static final String 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:
- Constant Field Values
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RESPONSE_HEADER_ACCESS_CONTROL_EXPOSE_HEADERS
public static final String 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:
- Constant Field Values
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RESPONSE_HEADER_ACCESS_CONTROL_MAX_AGE
public static final String 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:
- Constant Field Values
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RESPONSE_HEADER_ACCESS_CONTROL_ALLOW_METHODS
public static final String 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:
- Constant Field Values
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RESPONSE_HEADER_ACCESS_CONTROL_ALLOW_HEADERS
public static final String 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:
- Constant Field Values
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REQUEST_HEADER_ORIGIN
public static final String REQUEST_HEADER_ORIGIN
The Origin header indicates where the cross-origin request or preflight request originates from.- See Also:
- Constant Field Values
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REQUEST_HEADER_ACCESS_CONTROL_REQUEST_METHOD
public static final String 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:
- Constant Field Values
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REQUEST_HEADER_ACCESS_CONTROL_REQUEST_HEADERS
public static final String 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:
- Constant Field Values
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HTTP_REQUEST_ATTRIBUTE_PREFIX
public static final String HTTP_REQUEST_ATTRIBUTE_PREFIX
The prefix to a CORS request attribute.- See Also:
- Constant Field Values
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HTTP_REQUEST_ATTRIBUTE_ORIGIN
public static final String HTTP_REQUEST_ATTRIBUTE_ORIGIN
Attribute that contains the origin of the request.- See Also:
- Constant Field Values
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HTTP_REQUEST_ATTRIBUTE_IS_CORS_REQUEST
public static final String HTTP_REQUEST_ATTRIBUTE_IS_CORS_REQUEST
Boolean value, suggesting if the request is a CORS request or not.- See Also:
- Constant Field Values
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HTTP_REQUEST_ATTRIBUTE_REQUEST_TYPE
public static final String HTTP_REQUEST_ATTRIBUTE_REQUEST_TYPE
Type of CORS request, of typeCorsFilter.CORSRequestType
.- See Also:
- Constant Field Values
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HTTP_REQUEST_ATTRIBUTE_REQUEST_HEADERS
public static final String HTTP_REQUEST_ATTRIBUTE_REQUEST_HEADERS
Request headers sent as 'Access-Control-Request-Headers' header, for pre-flight request.- See Also:
- Constant Field Values
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SIMPLE_HTTP_REQUEST_CONTENT_TYPE_VALUES
public static final Collection<String> 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:
- http://www.w3.org/TR/cors/#terminology
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DEFAULT_ALLOWED_ORIGINS
public static final String DEFAULT_ALLOWED_ORIGINS
By default, no origins are allowed to make requests.- See Also:
- Constant Field Values
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DEFAULT_ALLOWED_HTTP_METHODS
public static final String DEFAULT_ALLOWED_HTTP_METHODS
By default, following methods are supported: GET, POST, HEAD and OPTIONS.- See Also:
- Constant Field Values
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DEFAULT_PREFLIGHT_MAXAGE
public static final String DEFAULT_PREFLIGHT_MAXAGE
By default, time duration to cache pre-flight response is 30 mins.- See Also:
- Constant Field Values
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DEFAULT_SUPPORTS_CREDENTIALS
public static final String DEFAULT_SUPPORTS_CREDENTIALS
By default, support credentials is disabled.- See Also:
- Constant Field Values
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DEFAULT_ALLOWED_HTTP_HEADERS
public static final String 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:
- Constant Field Values
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DEFAULT_EXPOSED_HEADERS
public static final String DEFAULT_EXPOSED_HEADERS
By default, none of the headers are exposed in response.- See Also:
- Constant Field Values
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DEFAULT_DECORATE_REQUEST
public static final String DEFAULT_DECORATE_REQUEST
By default, request is decorated with CORS attributes.- See Also:
- Constant Field Values
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PARAM_CORS_ALLOWED_ORIGINS
public static final String PARAM_CORS_ALLOWED_ORIGINS
Key to retrieve allowed origins fromFilterConfig
.- See Also:
- Constant Field Values
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PARAM_CORS_SUPPORT_CREDENTIALS
public static final String PARAM_CORS_SUPPORT_CREDENTIALS
Key to retrieve support credentials fromFilterConfig
.- See Also:
- Constant Field Values
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PARAM_CORS_EXPOSED_HEADERS
public static final String PARAM_CORS_EXPOSED_HEADERS
Key to retrieve exposed headers fromFilterConfig
.- See Also:
- Constant Field Values
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PARAM_CORS_ALLOWED_HEADERS
public static final String PARAM_CORS_ALLOWED_HEADERS
Key to retrieve allowed headers fromFilterConfig
.- See Also:
- Constant Field Values
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PARAM_CORS_ALLOWED_METHODS
public static final String PARAM_CORS_ALLOWED_METHODS
Key to retrieve allowed methods fromFilterConfig
.- See Also:
- Constant Field Values
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PARAM_CORS_PREFLIGHT_MAXAGE
public static final String PARAM_CORS_PREFLIGHT_MAXAGE
Key to retrieve preflight max age fromFilterConfig
.- See Also:
- Constant Field Values
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PARAM_CORS_REQUEST_DECORATE
public static final String PARAM_CORS_REQUEST_DECORATE
Key to determine if request should be decorated.- See Also:
- Constant Field Values
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Method Detail
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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
public void init() throws ServletException
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:
- Simple Cross-Origin Request, Actual Request, and Redirects
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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
protected static String join(Collection<String> elements, String joinSeparator)
Joins elements ofSet
into a string, where each element is separated by the provided separator.
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checkRequestType
protected CorsFilter.CORSRequestType checkRequestType(HttpServletRequest request)
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
public Collection<String> 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
public Collection<String> getAllowedOrigins()
Returns theSet
of allowed origins that are allowed to make requests.- Returns:
Set
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getAllowedHttpMethods
public Collection<String> getAllowedHttpMethods()
Returns aSet
of HTTP methods that are allowed to make requests.- Returns:
Set
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getAllowedHttpHeaders
public Collection<String> getAllowedHttpHeaders()
Returns aSet
of headers support by resource.- Returns:
Set
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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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