public interface ServletRequest
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.
HttpServletRequest| Modifier and Type | Method and Description |
|---|---|
AsyncContext |
getAsyncContext()
Get the current AsyncContext.
|
java.lang.Object |
getAttribute(java.lang.String name)
Returns the value of the named attribute as an
Object, or
null if no attribute of the given name exists. |
java.util.Enumeration<java.lang.String> |
getAttributeNames()
Returns an
Enumeration containing the names of the
attributes available to this request. |
java.lang.String |
getCharacterEncoding()
Returns the name of the character encoding used in the body of this
request.
|
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.
|
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.
|
java.lang.String |
getContentType()
Returns the MIME type of the body of the request, or
null if
the type is not known. |
DispatcherType |
getDispatcherType() |
ServletInputStream |
getInputStream()
Retrieves the body of the request as binary data using a
ServletInputStream. |
java.lang.String |
getLocalAddr()
Returns the Internet Protocol (IP) address of the interface on which the
request was received.
|
java.util.Locale |
getLocale()
Returns the preferred
Locale that the client will accept
content in, based on the Accept-Language header. |
java.util.Enumeration<java.util.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. |
java.lang.String |
getLocalName()
Returns the host name of the Internet Protocol (IP) interface on which
the request was received.
|
int |
getLocalPort()
Returns the Internet Protocol (IP) port number of the interface on which
the request was received.
|
java.lang.String |
getParameter(java.lang.String name)
Returns the value of a request parameter as a
String, or
null if the parameter does not exist. |
java.util.Map<java.lang.String,java.lang.String[]> |
getParameterMap()
Returns a java.util.Map of the parameters of this request.
|
java.util.Enumeration<java.lang.String> |
getParameterNames()
Returns an
Enumeration of String objects
containing the names of the parameters contained in this request. |
java.lang.String[] |
getParameterValues(java.lang.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. |
java.lang.String |
getProtocol()
Returns the name and version of the protocol the request uses in the form
protocol/majorVersion.minorVersion, for example, HTTP/1.1.
|
java.io.BufferedReader |
getReader()
Retrieves the body of the request as character data using a
BufferedReader. |
java.lang.String |
getRealPath(java.lang.String path)
Deprecated.
As of Version 2.1 of the Java Servlet API, use
ServletContext.getRealPath(java.lang.String) instead. |
java.lang.String |
getRemoteAddr()
Returns the Internet Protocol (IP) address of the client or last proxy
that sent the request.
|
java.lang.String |
getRemoteHost()
Returns the fully qualified name of the client or the last proxy that
sent the request.
|
int |
getRemotePort()
Returns the Internet Protocol (IP) source port of the client or last
proxy that sent the request.
|
RequestDispatcher |
getRequestDispatcher(java.lang.String path)
Returns a
RequestDispatcher object that acts as a wrapper for the
resource located at the given path. |
java.lang.String |
getScheme()
Returns the name of the scheme used to make this request, for example,
http, https, or ftp. |
java.lang.String |
getServerName()
Returns the host name of the server to which the request was sent.
|
int |
getServerPort()
Returns the port number to which the request was sent.
|
ServletContext |
getServletContext() |
boolean |
isAsyncStarted() |
boolean |
isAsyncSupported() |
boolean |
isSecure()
Returns a boolean indicating whether this request was made using a secure
channel, such as HTTPS.
|
void |
removeAttribute(java.lang.String name)
Removes an attribute from this request.
|
void |
setAttribute(java.lang.String name,
java.lang.Object o)
Stores an attribute in this request.
|
void |
setCharacterEncoding(java.lang.String env)
Overrides the name of the character encoding used in the body of this
request.
|
AsyncContext |
startAsync() |
AsyncContext |
startAsync(ServletRequest servletRequest,
ServletResponse servletResponse) |
java.lang.Object getAttribute(java.lang.String name)
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
javax.servlet.request.X509Certificate can be used to
retrieve information on the certificate of the client. Attributes can
also be set programmatically using setAttribute(java.lang.String, java.lang.Object).
This allows information to be embedded into a request before a
RequestDispatcher call.
Attribute names should follow the same conventions as package names.
Names beginning with java.* and javax.* are
reserved for use by the Servlet specification. Names beginning with
sun.*, com.sun.*, oracle.* and
com.oracle.*) are reserved for use by Oracle Corporation.
name - a String specifying the name of the attributeObject containing the value of the attribute, or
null if the attribute does not existjava.util.Enumeration<java.lang.String> getAttributeNames()
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.Enumeration of strings containing the names of the
request's attributesjava.lang.String getCharacterEncoding()
null if the request does not
specify a character encodingString containing the name of the character
encoding, or null if the request does not specify a
character encodingvoid setCharacterEncoding(java.lang.String env)
throws java.io.UnsupportedEncodingException
env - a String containing the name of the character
encoding.java.io.UnsupportedEncodingException - if this is not a valid encodingint getContentLength()
Integer.MAX_VALUElong getContentLengthLong()
java.lang.String getContentType()
null if
the type is not known. For HTTP servlets, same as the value of the CGI
variable CONTENT_TYPE.String containing the name of the MIME type of the
request, or null if the type is not knownServletInputStream getInputStream() throws java.io.IOException
ServletInputStream. Either this method or getReader() may
be called to read the body, not both.ServletInputStream object containing the body of the
requestjava.lang.IllegalStateException - if the getReader() method has already been called
for this requestjava.io.IOException - if an input or output exception occurredjava.lang.String getParameter(java.lang.String name)
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(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() or getReader() can interfere with the
execution of this method.
name - a String specifying the name of the parameterString representing the single value of the
parametergetParameterValues(java.lang.String)java.util.Enumeration<java.lang.String> getParameterNames()
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.Enumeration of String objects, each
String containing the name of a request parameter;
or an empty Enumeration if the request has no
parametersjava.lang.String[] getParameterValues(java.lang.String name)
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.
name - a String containing the name of the parameter
whose value is requestedString objects containing the parameter's
valuesgetParameter(java.lang.String)java.util.Map<java.lang.String,java.lang.String[]> getParameterMap()
java.lang.String getProtocol()
SERVER_PROTOCOL.String containing the protocol name and version
numberjava.lang.String getScheme()
http, https, or ftp. Different
schemes have different rules for constructing URLs, as noted in RFC 1738.String containing the name of the scheme used to
make this requestjava.lang.String getServerName()
Host header value,
if any, or the resolved server name, or the server IP address.String containing the name of the serverint getServerPort()
Host header value, if any, or the
server port where the client connection was accepted on.java.io.BufferedReader getReader()
throws java.io.IOException
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.BufferedReader containing the body of the requestjava.io.UnsupportedEncodingException - if the character set encoding used is not supported and
the text cannot be decodedjava.lang.IllegalStateException - if getInputStream() method has been called on this
requestjava.io.IOException - if an input or output exception occurredgetInputStream()java.lang.String getRemoteAddr()
REMOTE_ADDR.String containing the IP address of the client
that sent the requestjava.lang.String getRemoteHost()
REMOTE_HOST.String containing the fully qualified name of the
clientvoid setAttribute(java.lang.String name,
java.lang.Object o)
RequestDispatcher.
Attribute names should follow the same conventions as package names.
Names beginning with java.* and javax.* are
reserved for use by the Servlet specification. Names beginning with
sun.*, com.sun.*, oracle.* and
com.oracle.*) are reserved for use by Oracle Corporation.
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 by RequestDispatcher, the
object set by this method may not be correctly retrieved in the caller
servlet.
name - a String specifying the name of the attributeo - the Object to be storedvoid removeAttribute(java.lang.String name)
Attribute names should follow the same conventions as package names.
Names beginning with java.* and javax.* are
reserved for use by the Servlet specification. Names beginning with
sun.*, com.sun.*, oracle.* and
com.oracle.*) are reserved for use by Oracle Corporation.
name - a String specifying the name of the attribute to
removejava.util.Locale getLocale()
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.Locale for the clientjava.util.Enumeration<java.util.Locale> getLocales()
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.Enumeration of preferred Locale
objects for the clientboolean isSecure()
RequestDispatcher getRequestDispatcher(java.lang.String path)
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.
The difference between this method and
ServletContext.getRequestDispatcher(java.lang.String) is that this method can take
a relative path.
path - a String specifying the pathname to the resource.
If it is relative, it must be relative against the current
servlet.RequestDispatcher object that acts as a wrapper for
the resource at the specified path, or null if the
servlet container cannot return a RequestDispatcherRequestDispatcher,
ServletContext.getRequestDispatcher(java.lang.String)java.lang.String getRealPath(java.lang.String path)
ServletContext.getRealPath(java.lang.String) instead.path - The virtual path to be converted to a real pathServletContext.getRealPath(String)int getRemotePort()
java.lang.String getLocalName()
String containing the host name of the IP on which
the request was received.java.lang.String getLocalAddr()
String containing the IP address on which the
request was received.int getLocalPort()
ServletContext getServletContext()
AsyncContext startAsync() throws java.lang.IllegalStateException
java.lang.IllegalStateException - If async is not supported for this requestAsyncContext startAsync(ServletRequest servletRequest, ServletResponse servletResponse) throws java.lang.IllegalStateException
servletRequest - The ServletRequest with which to initialise the
asynchronous contextservletResponse - The ServletResponse with which to initialise the
asynchronous contextjava.lang.IllegalStateException - If async is not supported for this requestboolean isAsyncStarted()
boolean isAsyncSupported()
AsyncContext getAsyncContext()
java.lang.IllegalStateException - if the request is not in asynchronous mode
(i.e. @link #isAsyncStarted() is false)DispatcherType getDispatcherType()
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