Interface ServletRequest
- All Known Subinterfaces:
HttpServletRequest
- All Known Implementing Classes:
HttpServletRequestWrapper
,ServletRequestWrapper
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 HttpServletRequest
.
- See Also:
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Method Summary
Modifier and TypeMethodDescriptionGet the current AsyncContext.getAttribute
(String name) Returns the value of the named attribute as anObject
, ornull
if no attribute of the given name exists.Returns anEnumeration
containing the names of the attributes available to this request.Returns the name of the character encoding used in the body of this request.int
Returns the length, in bytes, of the request body and made available by the input stream, or -1 if the length is not known.long
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 the MIME type of the body of the request, ornull
if the type is not known.Retrieves the body of the request as binary data using aServletInputStream
.Returns the Internet Protocol (IP) address of the interface on which the request was received.Returns the preferredLocale
that the client will accept content in, based on the Accept-Language header.Returns anEnumeration
ofLocale
objects indicating, in decreasing order starting with the preferred locale, the locales that are acceptable to the client based on the Accept-Language header.Returns the host name of the Internet Protocol (IP) interface on which the request was received.int
Returns the Internet Protocol (IP) port number of the interface on which the request was received.getParameter
(String name) Returns the value of a request parameter as aString
, ornull
if the parameter does not exist.Returns a java.util.Map of the parameters of this request.Returns anEnumeration
ofString
objects containing the names of the parameters contained in this request.String[]
getParameterValues
(String name) Returns an array ofString
objects containing all of the values the given request parameter has, ornull
if the parameter does not exist.Returns the name and version of the protocol the request uses in the form protocol/majorVersion.minorVersion, for example, HTTP/1.1.Obtain the request identifier for this request as defined by the protocol in use.Retrieves the body of the request as character data using aBufferedReader
.Returns the Internet Protocol (IP) address of the client or last proxy that sent the request.Returns the fully qualified name of the client or the last proxy that sent the request.int
Returns the Internet Protocol (IP) source port of the client or last proxy that sent the request.getRequestDispatcher
(String path) Returns aRequestDispatcher
object that acts as a wrapper for the resource located at the given path.Obtain a unique (within the lifetime of the Servlet container) identifier string for this request.Returns the name of the scheme used to make this request, for example,http
,https
, orftp
.Returns the host name of the server to which the request was sent.int
Returns the port number to which the request was sent.Obtain details of the network connection to the Servlet container that is being used by this request.boolean
boolean
boolean
isSecure()
Returns a boolean indicating whether this request was made using a secure channel, such as HTTPS.void
removeAttribute
(String name) Removes an attribute from this request.void
setAttribute
(String name, Object o) Stores an attribute in this request.void
setCharacterEncoding
(String encoding) Overrides the name of the character encoding used in the body of this request.startAsync
(ServletRequest servletRequest, ServletResponse servletResponse)
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Method Details
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getAttribute
Returns the value of the named attribute as anObject
, ornull
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 usingsetAttribute(java.lang.String, java.lang.Object)
. This allows information to be embedded into a request before aRequestDispatcher
call.Attribute names should follow the same conventions as package names. Names beginning with
jakarta.*
are reserved for use by the Jakarta EE platform.- Parameters:
name
- aString
specifying the name of the attribute- Returns:
- an
Object
containing the value of the attribute, ornull
if the attribute does not exist
-
getAttributeNames
Enumeration<String> getAttributeNames()Returns anEnumeration
containing the names of the attributes available to this request. This method returns an emptyEnumeration
if the request has no attributes available to it.- Returns:
- an
Enumeration
of strings containing the names of the request's attributes
-
getCharacterEncoding
String getCharacterEncoding()Returns the name of the character encoding used in the body of this request. This method returnsnull
if the no character encoding has been specified. The following priority order is used to determine the specified encoding:- per request
- web application default via the deployment descriptor or
ServletContext.setRequestCharacterEncoding(String)
- container default via container specific configuration
- Returns:
- a
String
containing the name of the character encoding, ornull
if the request does not specify a character encoding
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setCharacterEncoding
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().- Parameters:
encoding
- aString
containing the name of the character encoding- Throws:
UnsupportedEncodingException
- if this is not a valid encoding
-
getContentLength
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. For HTTP servlets, same as the value of the CGI variable CONTENT_LENGTH.- 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
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getContentLengthLong
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. For HTTP servlets, same as the value of the CGI variable CONTENT_LENGTH.- Returns:
- a long integer containing the length of the request body or -1 if the length is not known
- Since:
- Servlet 3.1
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getContentType
String getContentType()Returns the MIME type of the body of the request, ornull
if the type is not known. For HTTP servlets, same as the value of the CGI variable CONTENT_TYPE.- Returns:
- a
String
containing the name of the MIME type of the request, or null if the type is not known
-
getInputStream
Retrieves the body of the request as binary data using aServletInputStream
. Either this method orgetReader()
may be called to read the body, not both.- Returns:
- a
ServletInputStream
object containing the body of the request - Throws:
IllegalStateException
- if thegetReader()
method has already been called for this requestIOException
- if an input or output exception occurred
-
getParameter
Returns the value of a request parameter as aString
, ornull
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(java.lang.String)
.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()
orgetReader()
can interfere with the execution of this method.- Parameters:
name
- aString
specifying the name of the parameter- Returns:
- a
String
representing the single value of the parameter - See Also:
-
getParameterNames
Enumeration<String> getParameterNames()Returns anEnumeration
ofString
objects containing the names of the parameters contained in this request. If the request has no parameters, the method returns an emptyEnumeration
.- Returns:
- an
Enumeration
ofString
objects, eachString
containing the name of a request parameter; or an emptyEnumeration
if the request has no parameters
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getParameterValues
Returns an array ofString
objects containing all of the values the given request parameter has, ornull
if the parameter does not exist.If the parameter has a single value, the array has a length of 1.
- Parameters:
name
- aString
containing the name of the parameter whose value is requested- Returns:
- an array of
String
objects containing the parameter's values - See Also:
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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:
- 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.
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getProtocol
String getProtocol()Returns the name and version of the protocol the request uses in the form protocol/majorVersion.minorVersion, for example, HTTP/1.1. For HTTP servlets, the value returned is the same as the value of the CGI variableSERVER_PROTOCOL
.- Returns:
- a
String
containing the protocol name and version number
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getScheme
String getScheme()Returns the name of the scheme used to make this request, for example,http
,https
, orftp
. Different schemes have different rules for constructing URLs, as noted in RFC 1738.- Returns:
- a
String
containing the name of the scheme used to make this request
-
getServerName
String getServerName()Returns the host name of the server to which the request was sent. It is the value of the part before ":" in theHost
header value, if any, or the resolved server name, or the server IP address.- Returns:
- a
String
containing the name of the server
-
getServerPort
int getServerPort()Returns the port number to which the request was sent. It is the value of the part after ":" in theHost
header value, if any, or the server port where the client connection was accepted on.- Returns:
- an integer specifying the port number
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getReader
Retrieves the body of the request as character data using aBufferedReader
. The reader translates the character data according to the character encoding used on the body. Either this method orgetInputStream()
may be called to read the body, not both.- Returns:
- a
BufferedReader
containing the body of the request - Throws:
UnsupportedEncodingException
- if the character set encoding used is not supported and the text cannot be decodedIllegalStateException
- ifgetInputStream()
method has been called on this requestIOException
- if an input or output exception occurred- See Also:
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getRemoteAddr
String getRemoteAddr()Returns the Internet Protocol (IP) address of the client or last proxy that sent the request. For HTTP servlets, same as the value of the CGI variableREMOTE_ADDR
.- Returns:
- a
String
containing the IP address of the client that sent the request
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getRemoteHost
String getRemoteHost()Returns the fully qualified name of the client or the last proxy that sent the request. If the engine cannot or chooses not to resolve the hostname (to improve performance), this method returns the dotted-string form of the IP address. For HTTP servlets, same as the value of the CGI variableREMOTE_HOST
.- Returns:
- a
String
containing the fully qualified name of the client
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setAttribute
Stores an attribute in this request. Attributes are reset between requests. This method is most often used in conjunction withRequestDispatcher
.Attribute names should follow the same conventions as package names. Names beginning with
jakarta.*
are reserved for use by the Jakarta EE platform.If the object passed in is null, the effect is the same as calling
removeAttribute(java.lang.String)
.
It is warned that when the request is dispatched from the servlet resides in a different web application byRequestDispatcher
, the object set by this method may not be correctly retrieved in the caller servlet.- Parameters:
name
- aString
specifying the name of the attributeo
- theObject
to be stored
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removeAttribute
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
jakarta.*
are reserved for use by the Jakarta EE platform.- Parameters:
name
- aString
specifying the name of the attribute to remove
-
getLocale
Locale getLocale()Returns the preferredLocale
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:
- the preferred
Locale
for the client
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getLocales
Enumeration<Locale> getLocales()Returns anEnumeration
ofLocale
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 anEnumeration
containing oneLocale
, the default locale for the server.- Returns:
- an
Enumeration
of preferredLocale
objects for the client
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isSecure
boolean isSecure()Returns a boolean indicating whether this request was made using a secure channel, such as HTTPS.- Returns:
- a boolean indicating if the request was made using a secure channel
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getRequestDispatcher
Returns aRequestDispatcher
object that acts as a wrapper for the resource located at the given path. ARequestDispatcher
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 aRequestDispatcher
.The difference between this method and
ServletContext.getRequestDispatcher(java.lang.String)
is that this method can take a relative path.- Parameters:
path
- aString
specifying the pathname to the resource. If it is relative, it must be relative against the current servlet.- Returns:
- a
RequestDispatcher
object that acts as a wrapper for the resource at the specified path, ornull
if the servlet container cannot return aRequestDispatcher
- See Also:
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getRemotePort
int getRemotePort()Returns the Internet Protocol (IP) source port of the client or last proxy that sent the request.- Returns:
- an integer specifying the port number
- Since:
- Servlet 2.4
-
getLocalName
String getLocalName()Returns the host name of the Internet Protocol (IP) interface on which the request was received.- Returns:
- a
String
containing the host name of the IP on which the request was received. - Since:
- Servlet 2.4
-
getLocalAddr
String getLocalAddr()Returns the Internet Protocol (IP) address of the interface on which the request was received.- Returns:
- a
String
containing the IP address on which the request was received. - Since:
- Servlet 2.4
-
getLocalPort
int getLocalPort()Returns the Internet Protocol (IP) port number of the interface on which the request was received.- Returns:
- an integer specifying the port number
- Since:
- Servlet 2.4
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getServletContext
ServletContext getServletContext()- Returns:
- TODO
- Since:
- Servlet 3.0 TODO SERVLET3 - Add comments
-
startAsync
- Returns:
- TODO
- Throws:
IllegalStateException
- If async is not supported for this request- Since:
- Servlet 3.0 TODO SERVLET3 - Add comments
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startAsync
AsyncContext startAsync(ServletRequest servletRequest, ServletResponse servletResponse) throws IllegalStateException - Parameters:
servletRequest
- The ServletRequest with which to initialise the asynchronous contextservletResponse
- The ServletResponse with which to initialise the asynchronous context- Returns:
- TODO
- Throws:
IllegalStateException
- If async is not supported for this request- Since:
- Servlet 3.0 TODO SERVLET3 - Add comments
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isAsyncStarted
boolean isAsyncStarted()- Returns:
- TODO
- Since:
- Servlet 3.0 TODO SERVLET3 - Add comments
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isAsyncSupported
boolean isAsyncSupported()- Returns:
- TODO
- Since:
- Servlet 3.0 TODO SERVLET3 - Add comments
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getAsyncContext
AsyncContext getAsyncContext()Get the current AsyncContext.- Returns:
- The current AsyncContext
- Throws:
IllegalStateException
- if the request is not in asynchronous mode (i.e. @link #isAsyncStarted() isfalse
)- Since:
- Servlet 3.0
-
getDispatcherType
DispatcherType getDispatcherType()- Returns:
- TODO
- Since:
- Servlet 3.0 TODO SERVLET3 - Add comments
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getRequestId
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:
- A unique identifier for the request
- Since:
- Servlet 6.0
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getProtocolRequestId
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:
- The request identifier if one is defined, otherwise an empty string
- Since:
- Servlet 6.0
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getServletConnection
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:
- The network connection details.
- Since:
- Servlet 6.0
-