Top Description Methods
jakarta.servlet

public Interface ServletRequest

Known Direct Subinterfaces
jakarta.servlet.http.HttpServletRequest
Known Direct Implementers
jakarta.servlet.ServletRequestWrapper
Imports
java.io.*, java.util.*

Defines an object to provide client request information to a servlet. The servlet container creates a ServletRequest object and passes it as an argument to the servlet's service method.

A ServletRequest object provides data including parameter name and values, attributes, and an input stream. Interfaces that extend ServletRequest can provide additional protocol-specific data (for example, HTTP data is provided by jakarta.servlet.http.HttpServletRequest.

Author
Various
See Also
jakarta.servlet.http.HttpServletRequest

Method Summary

Modifier and TypeMethod and Description
public AsyncContext

Returns:

the AsyncContext that was created or reinitialized by the most recent invocation of startAsync or startAsync(ServletRequest, ServletResponse) on this request
getAsyncContext
()

Gets the AsyncContext that was created or reinitialized by the most recent invocation of startAsync or startAsync(ServletRequest, ServletResponse) on this request.

public Object

Returns:

an Object containing the value of the attribute, or null if the attribute does not exist
getAttribute
(String
a String specifying the name of the attribute
name
)

Returns the value of the named attribute as an Object, or null if no attribute of the given name exists.

public Enumeration<String>

Returns:

an Enumeration of strings containing the names of the request's attributes
getAttributeNames
()

Returns an Enumeration containing the names of the attributes available to this request.

public String

Returns:

a String containing the name of the character encoding, or null if the request does not specify a character encoding
getCharacterEncoding
()

Returns the name of the character encoding used in the body of this request.

public int

Returns:

an integer containing the length of the request body or -1 if the length is not known or is greater than Integer.MAX_VALUE.
getContentLength
()

Returns the length, in bytes, of the request body and made available by the input stream, or -1 if the length is not known or is greater than Integer.MAX_VALUE.

public long

Returns:

a long containing the length of the request body or -1L if the length is not known
getContentLengthLong
()

Returns the length, in bytes, of the request body and made available by the input stream, or -1 if the length is not known.

public String

Returns:

a String containing the name of the MIME type of the request, or null if the type is not known
getContentType
()

Returns the MIME type of the body of the request, or null if the type is not known.

public DispatcherType

Returns:

the dispatcher type of this request
getDispatcherType
()

Gets the dispatcher type of this request.

public ServletInputStream

Returns:

a ServletInputStream object containing the body of the request
getInputStream
()

Retrieves the body of the request as binary data using a ServletInputStream.

public String

Returns:

a String containing an IP address.
getLocalAddr
()

Returns the Internet Protocol (IP) address representing the interface on which the request was received.

public Locale

Returns:

the preferred Locale for the client
getLocale
()

Returns the preferred Locale that the client will accept content in, based on the Accept-Language header.

public Enumeration<Locale>

Returns:

an Enumeration of preferred Locale objects for the client
getLocales
()

Returns an Enumeration of Locale objects indicating, in decreasing order starting with the preferred locale, the locales that are acceptable to the client based on the Accept-Language header.

public String

Returns:

a String containing the host name of the IP on which the request was received.
getLocalName
()

Returns the fully qualified name of the address returned by getLocalAddr().

public int

Returns:

an integer specifying a port number
getLocalPort
()

Returns the Internet Protocol (IP) port number representing the interface on which the request was received.

public String

Returns:

a String representing the single value of the parameter
getParameter
(String
a String specifying the name of the parameter
name
)

Returns the value of a request parameter as a String, or null if the parameter does not exist.

public Map<String, String[]>

Returns:

an immutable java.util.Map containing parameter names as keys and parameter values as map values. The keys in the parameter map are of type String. The values in the parameter map are of type String array.
getParameterMap
()

Returns a java.util.Map of the parameters of this request.

public Enumeration<String>

Returns:

an Enumeration of String objects, each String containing the name of a request parameter; or an empty Enumeration if the request has no parameters
getParameterNames
()

Returns an Enumeration of String objects containing the names of the parameters contained in this request.

public String[]

Returns:

an array of String objects containing the parameter's values
getParameterValues
(String
a String containing the name of the parameter whose value is requested
name
)

Returns an array of String objects containing all of the values the given request parameter has, or null if the parameter does not exist.

public String

Returns:

a String containing the protocol name and version number
getProtocol
()

Returns the name and version of the protocol the request uses in the form protocol/majorVersion.minorVersion, for example, HTTP/1.1.

public String

Returns:

The request identifier if one is defined, otherwise an empty string
getProtocolRequestId
()

Obtain the request identifier for this request as defined by the protocol in use.

public BufferedReader

Returns:

a BufferedReader containing the body of the request
getReader
()

Retrieves the body of the request as character data using a BufferedReader.

public String

Returns:

a String containing an IP address
getRemoteAddr
()

Returns the Internet Protocol (IP) of the remote end of the connection on which the request was received.

public String

Returns:

a String containing a fully qualified name or IP address.
getRemoteHost
()

Returns the fully qualified name of the address returned by getRemoteAddr().

public int

Returns:

an integer specifying the port number
getRemotePort
()

Returns the Internet Protocol (IP) source port the remote end of the connection on which the request was received.

public RequestDispatcher

Returns:

a RequestDispatcher object that acts as a wrapper for the resource at the specified path, or null if the servlet container cannot return a RequestDispatcher
getRequestDispatcher
(String
a String specifying the pathname to the resource. If it is relative, it must be relative against the current servlet.
path
)

Returns a RequestDispatcher object that acts as a wrapper for the resource located at the given path.

public String

Returns:

A unique identifier for the request
getRequestId
()

Obtain a unique (within the lifetime of the Servlet container) identifier string for this request.

public String

Returns:

a String containing the name of the scheme used to make this request
getScheme
()

Returns the name of the scheme used to make this request, for example, http, https, or ftp.

public String

Returns:

a String containing the name of the server
getServerName
()

Returns the host name of the server to which the request was sent.

public int

Returns:

an integer specifying the port number
getServerPort
()

Returns the port number to which the request was sent.

public ServletConnection

Returns:

The network connection details.
getServletConnection
()

Obtain details of the network connection to the Servlet container that is being used by this request.

public ServletContext

Returns:

the servlet context to which this ServletRequest was last dispatched
getServletContext
()

Gets the servlet context to which this ServletRequest was last dispatched.

public boolean

Returns:

true if this request has been put into asynchronous mode, false otherwise
isAsyncStarted
()

Checks if this request has been put into asynchronous mode.

public boolean

Returns:

true if this request supports asynchronous operation, false otherwise
isAsyncSupported
()

Checks if this request supports asynchronous operation.

public boolean

Returns:

a boolean indicating if the request was made using a secure channel
isSecure
()

Returns a boolean indicating whether this request was made using a secure channel, such as HTTPS.

public void
removeAttribute(String
a String specifying the name of the attribute to remove
name
)

Removes an attribute from this request.

public void
setAttribute(String
a String specifying the name of the attribute
name
,
Object
the Object to be stored
o
)

Stores an attribute in this request.

public void
setCharacterEncoding(String
String containing the name of the character encoding.
env
)

Overrides the name of the character encoding used in the body of this request.

public AsyncContext

Returns:

the (re)initialized AsyncContext
startAsync
()

Puts this request into asynchronous mode, and initializes its AsyncContext with the original (unwrapped) ServletRequest and ServletResponse objects.

public AsyncContext

Returns:

the (re)initialized AsyncContext
startAsync
(ServletRequest
the ServletRequest used to initialize the AsyncContext
servletRequest
,
ServletResponse
the ServletResponse used to initialize the AsyncContext
servletResponse
)

Puts this request into asynchronous mode, and initializes its AsyncContext with the given request and response objects.

Method Detail

getAsyncContextback to summary
public AsyncContext getAsyncContext()

Gets the AsyncContext that was created or reinitialized by the most recent invocation of startAsync or startAsync(ServletRequest, ServletResponse) on this request.

Returns:AsyncContext

the AsyncContext that was created or reinitialized by the most recent invocation of startAsync or startAsync(ServletRequest, ServletResponse) on this request

Exceptions
IllegalStateException:
if this request has not been put into asynchronous mode, i.e., if neither startAsync nor startAsync(ServletRequest, ServletResponse) has been called
Since
Servlet 3.0
getAttributeback to summary
public Object getAttribute(String name)

Returns the value of the named attribute as an Object, or null if no attribute of the given name exists.

Attributes can be set two ways. The servlet container may set attributes to make available custom information about a request. For example, for requests made using HTTPS, the attribute jakarta.servlet.request.X509Certificate can be used to retrieve information on the certificate of the client. Attributes can also be set programmatically using ServletRequest#setAttribute. This allows information to be embedded into a request before a RequestDispatcher call.

Attribute names should follow the same conventions as package names. This specification reserves names matching java.*, javax.*, and sun.*.

Parameters
name:String

a String specifying the name of the attribute

Returns:Object

an Object containing the value of the attribute, or null if the attribute does not exist

getAttributeNamesback to summary
public Enumeration<String> getAttributeNames()

Returns an Enumeration containing the names of the attributes available to this request. This method returns an empty Enumeration if the request has no attributes available to it.

Returns:Enumeration<String>

an Enumeration of strings containing the names of the request's attributes

getCharacterEncodingback to summary
public String getCharacterEncoding()

Returns the name of the character encoding used in the body of this request. This method returns null if no request encoding character encoding has been specified. The following methods for specifying the request character encoding are consulted, in decreasing order of priority: per request, per web app (using ServletContext#setRequestCharacterEncoding, deployment descriptor), and per container (for all web applications deployed in that container, using vendor specific configuration).

Returns:String

a String containing the name of the character encoding, or null if the request does not specify a character encoding

getContentLengthback to summary
public int getContentLength()

Returns the length, in bytes, of the request body and made available by the input stream, or -1 if the length is not known or is greater than Integer.MAX_VALUE.

Returns:int

an integer containing the length of the request body or -1 if the length is not known or is greater than Integer.MAX_VALUE.

getContentLengthLongback to summary
public long getContentLengthLong()

Returns the length, in bytes, of the request body and made available by the input stream, or -1 if the length is not known.

Returns:long

a long containing the length of the request body or -1L if the length is not known

Since
Servlet 3.1
getContentTypeback to summary
public String getContentType()

Returns the MIME type of the body of the request, or null if the type is not known.

Returns:String

a String containing the name of the MIME type of the request, or null if the type is not known

getDispatcherTypeback to summary
public DispatcherType getDispatcherType()

Gets the dispatcher type of this request.

The dispatcher type of a request is used by the container to select the filters that need to be applied to the request: Only filters with matching dispatcher type and url patterns will be applied.

Allowing a filter that has been configured for multiple dispatcher types to query a request for its dispatcher type allows the filter to process the request differently depending on its dispatcher type.

The initial dispatcher type of a request is defined as DispatcherType.REQUEST. The dispatcher type of a request dispatched via RequestDispatcher#forward(ServletRequest, ServletResponse) or RequestDispatcher#include(ServletRequest, ServletResponse) is given as DispatcherType.FORWARD or DispatcherType.INCLUDE, respectively, while the dispatcher type of an asynchronous request dispatched via one of the AsyncContext#dispatch methods is given as DispatcherType.ASYNC. Finally, the dispatcher type of a request dispatched to an error page by the container's error handling mechanism is given as DispatcherType.ERROR.

Returns:DispatcherType

the dispatcher type of this request

Since
Servlet 3.0
See Also
DispatcherType
getInputStreamback to summary
public ServletInputStream getInputStream() throws IOException

Retrieves the body of the request as binary data using a ServletInputStream. Either this method or getReader may be called to read the body, not both.

Returns:ServletInputStream

a ServletInputStream object containing the body of the request

Exceptions
IOException:
if an input or output exception occurred
IllegalStateException:
if the getReader method has already been called for this request
getLocalAddrback to summary
public String getLocalAddr()

Returns the Internet Protocol (IP) address representing the interface on which the request was received. In some cases a protocol specific mechanism, such as RFC 7239, may be used to obtain an address different to that of the actual TCP/IP connection.

Returns:String

a String containing an IP address.

Since
Servlet 2.4
getLocaleback to summary
public Locale getLocale()

Returns the preferred Locale that the client will accept content in, based on the Accept-Language header. If the client request doesn't provide an Accept-Language header, this method returns the default locale for the server.

Returns:Locale

the preferred Locale for the client

getLocalesback to summary
public Enumeration<Locale> getLocales()

Returns an Enumeration of Locale objects indicating, in decreasing order starting with the preferred locale, the locales that are acceptable to the client based on the Accept-Language header. If the client request doesn't provide an Accept-Language header, this method returns an Enumeration containing one Locale, the default locale for the server.

Returns:Enumeration<Locale>

an Enumeration of preferred Locale objects for the client

getLocalNameback to summary
public String getLocalName()

Returns the fully qualified name of the address returned by getLocalAddr(). If the engine cannot or chooses not to resolve the hostname (to improve performance), this method returns the IP address.

Returns:String

a String containing the host name of the IP on which the request was received.

Since
Servlet 2.4
getLocalPortback to summary
public int getLocalPort()

Returns the Internet Protocol (IP) port number representing the interface on which the request was received. In some cases, a protocol specific mechanism such as RFC 7239 may be used to obtain an address different to that of the actual TCP/IP connection.

Returns:int

an integer specifying a port number

Since
Servlet 2.4
getParameterback to summary
public String getParameter(String name)

Returns the value of a request parameter as a String, or null if the parameter does not exist. Request parameters are extra information sent with the request. For HTTP servlets, parameters are contained in the query string or posted form data.

You should only use this method when you are sure the parameter has only one value. If the parameter might have more than one value, use getParameterValues.

If you use this method with a multivalued parameter, the value returned is equal to the first value in the array returned by getParameterValues.

If the parameter data was sent in the request body, such as occurs with an HTTP POST request, then reading the body directly via getInputStream or getReader can interfere with the execution of this method.

Parameters
name:String

a String specifying the name of the parameter

Returns:String

a String representing the single value of the parameter

See Also
getParameterValues
getParameterMapback to summary
public Map<String, String[]> getParameterMap()

Returns a java.util.Map of the parameters of this request.

Request parameters are extra information sent with the request. For HTTP servlets, parameters are contained in the query string or posted form data.

Returns:Map<String, String[]>

an immutable java.util.Map containing parameter names as keys and parameter values as map values. The keys in the parameter map are of type String. The values in the parameter map are of type String array.

getParameterNamesback to summary
public Enumeration<String> getParameterNames()

Returns an Enumeration of String objects containing the names of the parameters contained in this request. If the request has no parameters, the method returns an empty Enumeration.

Returns:Enumeration<String>

an Enumeration of String objects, each String containing the name of a request parameter; or an empty Enumeration if the request has no parameters

getParameterValuesback to summary
public String[] getParameterValues(String name)

Returns an array of String objects containing all of the values the given request parameter has, or null if the parameter does not exist.

If the parameter has a single value, the array has a length of 1.

Parameters
name:String

a String containing the name of the parameter whose value is requested

Returns:String[]

an array of String objects containing the parameter's values

See Also
getParameter
getProtocolback to summary
public String getProtocol()

Returns the name and version of the protocol the request uses in the form protocol/majorVersion.minorVersion, for example, HTTP/1.1.

Returns:String

a String containing the protocol name and version number

getProtocolRequestIdback to summary
public String getProtocolRequestId()

Obtain the request identifier for this request as defined by the protocol in use. Note that some protocols do not define such an identifier.

Examples of protocol provided request identifiers include:

HTTP 1.x
None, so the empty string should be returned
HTTP 2
The stream identifier
HTTP 3
The stream identifier
AJP
None, so the empty string should be returned
Returns:String

The request identifier if one is defined, otherwise an empty string

Since
Servlet 6.0
getReaderback to summary
public BufferedReader getReader() throws IOException

Retrieves the body of the request as character data using a BufferedReader. The reader translates the character data according to the character encoding used on the body. Either this method or getInputStream may be called to read the body, not both.

Returns:BufferedReader

a BufferedReader containing the body of the request

Exceptions
IOException:
if an input or output exception occurred
UnsupportedEncodingException:
if the character set encoding used is not supported and the text cannot be decoded
IllegalStateException:
if getInputStream method has been called on this request
See Also
getInputStream
getRemoteAddrback to summary
public String getRemoteAddr()

Returns the Internet Protocol (IP) of the remote end of the connection on which the request was received. By default this is either the address of the client or last proxy that sent the request. In some cases a protocol specific mechanism, such as RFC 7239, may be used to obtain an address different to that of the actual TCP/IP connection.

Returns:String

a String containing an IP address

getRemoteHostback to summary
public String getRemoteHost()

Returns the fully qualified name of the address returned by getRemoteAddr(). If the engine cannot or chooses not to resolve the hostname (to improve performance), this method returns the IP address.

Returns:String

a String containing a fully qualified name or IP address.

getRemotePortback to summary
public int getRemotePort()

Returns the Internet Protocol (IP) source port the remote end of the connection on which the request was received. By default this is either the port of the client or last proxy that sent the request. In some cases, protocol specific mechanisms such as RFC 7239 may be used to obtain a port different to that of the actual TCP/IP connection.

Returns:int

an integer specifying the port number

Since
Servlet 2.4
getRequestDispatcherback to summary
public RequestDispatcher getRequestDispatcher(String path)

Returns a RequestDispatcher object that acts as a wrapper for the resource located at the given path. A RequestDispatcher object can be used to forward a request to the resource or to include the resource in a response. The resource can be dynamic or static.

The pathname specified may be relative, although it cannot extend outside the current servlet context. If the path begins with a "/" it is interpreted as relative to the current context root. This method returns null if the servlet container cannot return a RequestDispatcher.

Using a RequestDispatcher, requests may be dispatched to any part of the web application bypassing both implicit (no direct access to WEB-INF or META-INF) and explicit (defined by the web application) security constraints. Unsanitized user provided data must not be used to construct the path passed to the RequestDispatcher as it is very likely to create a security vulnerability in the application.

The difference between this method and ServletContext#getRequestDispatcher is that this method can take a relative path.

Parameters
path:String

a String specifying the pathname to the resource. If it is relative, it must be relative against the current servlet.

Returns:RequestDispatcher

a RequestDispatcher object that acts as a wrapper for the resource at the specified path, or null if the servlet container cannot return a RequestDispatcher

See Also
RequestDispatcher, ServletContext#getRequestDispatcher
getRequestIdback to summary
public String getRequestId()

Obtain a unique (within the lifetime of the Servlet container) identifier string for this request.

There is no defined format for this string. The format is implementation dependent.

Returns:String

A unique identifier for the request

Since
Servlet 6.0
getSchemeback to summary
public String getScheme()

Returns the name of the scheme used to make this request, for example, http, https, or ftp. Different schemes have different rules for constructing URLs, as noted in RFC 1738.

Returns:String

a String containing the name of the scheme used to make this request

getServerNameback to summary
public String getServerName()

Returns the host name of the server to which the request was sent. It may be derived from a protocol specific mechanism, such as the Host header, or the HTTP/2 authority, or RFC 7239, otherwise the resolved server name or the server IP address.

Returns:String

a String containing the name of the server

getServerPortback to summary
public int getServerPort()

Returns the port number to which the request was sent. It may be derived from a protocol specific mechanism, such as the Host header, or HTTP authority, or RFC 7239, otherwise the server port where the client connection was accepted on.

Returns:int

an integer specifying the port number

getServletConnectionback to summary
public ServletConnection getServletConnection()

Obtain details of the network connection to the Servlet container that is being used by this request. The information presented may differ from information presented elsewhere in the Servlet API as raw information is presented without adjustments for, example, use of reverse proxies that may be applied elsewhere in the Servlet API.

Returns:ServletConnection

The network connection details.

Since
Servlet 6.0
getServletContextback to summary
public ServletContext getServletContext()

Gets the servlet context to which this ServletRequest was last dispatched.

Returns:ServletContext

the servlet context to which this ServletRequest was last dispatched

Since
Servlet 3.0
isAsyncStartedback to summary
public boolean isAsyncStarted()

Checks if this request has been put into asynchronous mode.

A ServletRequest is put into asynchronous mode by calling startAsync or startAsync(ServletRequest, ServletResponse) on it.

This method returns false if this request was put into asynchronous mode, but has since been dispatched using one of the AsyncContext#dispatch methods or released from asynchronous mode via a call to AsyncContext#complete. If AsyncContext#dispatch or AsyncContext#complete is called before the container-initiated dispatch that called ServletRequest#startAsync() has returned to the container then this method must return true until the container-initiated dispatch that called ServletRequest#startAsync() has returned to the container.

Returns:boolean

true if this request has been put into asynchronous mode, false otherwise

Since
Servlet 3.0
isAsyncSupportedback to summary
public boolean isAsyncSupported()

Checks if this request supports asynchronous operation.

Asynchronous operation is disabled for this request if this request is within the scope of a filter or servlet that has not been annotated or flagged in the deployment descriptor as being able to support asynchronous handling.

Returns:boolean

true if this request supports asynchronous operation, false otherwise

Since
Servlet 3.0
isSecureback to summary
public boolean isSecure()

Returns a boolean indicating whether this request was made using a secure channel, such as HTTPS.

Returns:boolean

a boolean indicating if the request was made using a secure channel

removeAttributeback to summary
public void removeAttribute(String name)

Removes an attribute from this request. This method is not generally needed as attributes only persist as long as the request is being handled.

Attribute names should follow the same conventions as package names. Names beginning with java.*, javax.*, and com.sun.*, are reserved for use by Sun Microsystems.

Parameters
name:String

a String specifying the name of the attribute to remove

setAttributeback to summary
public void setAttribute(String name, Object o)

Stores an attribute in this request. Attributes are reset between requests. This method is most often used in conjunction with RequestDispatcher.

Attribute names should follow the same conventions as package names.
If the object passed in is null, the effect is the same as calling removeAttribute.
It is warned that when the request is dispatched from the servlet resides in a different web application by RequestDispatcher, the object set by this method may not be correctly retrieved in the caller servlet.

Parameters
name:String

a String specifying the name of the attribute

o:Object

the Object to be stored

setCharacterEncodingback to summary
public void setCharacterEncoding(String env) throws UnsupportedEncodingException

Overrides the name of the character encoding used in the body of this request. This method must be called prior to reading request parameters or reading input using getReader(). Otherwise, it has no effect.

Parameters
env:String

String containing the name of the character encoding.

Exceptions
UnsupportedEncodingException:
if this ServletRequest is still in a state where a character encoding may be set, but the specified encoding is invalid
startAsyncback to summary
public AsyncContext startAsync() throws IllegalStateException

Puts this request into asynchronous mode, and initializes its AsyncContext with the original (unwrapped) ServletRequest and ServletResponse objects.

Calling this method will cause committal of the associated response to be delayed until AsyncContext#complete is called on the returned AsyncContext, or the asynchronous operation has timed out.

Calling AsyncContext#hasOriginalRequestAndResponse() on the returned AsyncContext will return true. Any filters invoked in the outbound direction after this request was put into asynchronous mode may use this as an indication that any request and/or response wrappers that they added during their inbound invocation need not stay around for the duration of the asynchronous operation, and therefore any of their associated resources may be released.

This method clears the list of AsyncListener instances (if any) that were registered with the AsyncContext returned by the previous call to one of the startAsync methods, after calling each AsyncListener at its onStartAsync method.

Subsequent invocations of this method, or its overloaded variant, will return the same AsyncContext instance, reinitialized as appropriate.

Returns:AsyncContext

the (re)initialized AsyncContext

Exceptions
IllegalStateException:
if this request is within the scope of a filter or servlet that does not support asynchronous operations (that is, isAsyncSupported returns false), or if this method is called again without any asynchronous dispatch (resulting from one of the AsyncContext#dispatch methods), is called outside the scope of any such dispatch, or is called again within the scope of the same dispatch, or if the response has already been closed
Since
Servlet 3.0
See Also
AsyncContext#dispatch()
startAsyncback to summary
public AsyncContext startAsync(ServletRequest servletRequest, ServletResponse servletResponse) throws IllegalStateException

Puts this request into asynchronous mode, and initializes its AsyncContext with the given request and response objects.

The ServletRequest and ServletResponse arguments must be the same instances, or instances of ServletRequestWrapper and ServletResponseWrapper that wrap them, that were passed to the service method of the Servlet or the doFilter method of the Filter, respectively, in whose scope this method is being called.

Calling this method will cause committal of the associated response to be delayed until AsyncContext#complete is called on the returned AsyncContext, or the asynchronous operation has timed out.

Calling AsyncContext#hasOriginalRequestAndResponse() on the returned AsyncContext will return false, unless the passed in ServletRequest and ServletResponse arguments are the original ones or do not carry any application-provided wrappers. Any filters invoked in the outbound direction after this request was put into asynchronous mode may use this as an indication that some of the request and/or response wrappers that they added during their inbound invocation may need to stay in place for the duration of the asynchronous operation, and their associated resources may not be released. A ServletRequestWrapper applied during the inbound invocation of a filter may be released by the outbound invocation of the filter only if the given servletRequest, which is used to initialize the AsyncContext and will be returned by a call to AsyncContext#getRequest(), does not contain said ServletRequestWrapper. The same holds true for ServletResponseWrapper instances.

This method clears the list of AsyncListener instances (if any) that were registered with the AsyncContext returned by the previous call to one of the startAsync methods, after calling each AsyncListener at its onStartAsync method.

Subsequent invocations of this method, or its zero-argument variant, will return the same AsyncContext instance, reinitialized as appropriate. If a call to this method is followed by a call to its zero-argument variant, the specified (and possibly wrapped) request and response objects will remain locked in on the returned AsyncContext.

Parameters
servletRequest:ServletRequest

the ServletRequest used to initialize the AsyncContext

servletResponse:ServletResponse

the ServletResponse used to initialize the AsyncContext

Returns:AsyncContext

the (re)initialized AsyncContext

Exceptions
IllegalStateException:
if this request is within the scope of a filter or servlet that does not support asynchronous operations (that is, isAsyncSupported returns false), or if this method is called again without any asynchronous dispatch (resulting from one of the AsyncContext#dispatch methods), is called outside the scope of any such dispatch, or is called again within the scope of the same dispatch, or if the response has already been closed
Since
Servlet 3.0