javax.servlet

Interface ServletRequest

All Known Subinterfaces:

HttpServletRequest

All Known Implementing Classes:

HttpServletRequestWrapper, ServletRequestWrapper

public interface ServletRequest

Whenever the server receives a request it creates a ServletRequest object, puts all the request information in it and passes this along with a ServletResponse object to the approriate servlet.

Since:

1.0

Method Summary

Methods

Modifier and Type	Method and Description
AsyncContext	getAsyncContext() Returns the current context for asynchronous operation.
java.lang.Object	getAttribute(java.lang.String name) Gets a named attribute's value.
java.util.Enumeration	getAttributeNames() Gets an Enumeration of all the attribute names.
java.lang.String	getCharacterEncoding() Gets the character encoding of the request data.
int	getContentLength() Gets the size in bytes of the request
java.lang.String	getContentType() Gets the mime type of the request
DispatcherType	getDispatcherType() Returns the dispatcher type of this request.
ServletInputStream	getInputStream() Creates an inputstream for servlets to read client request data from.
java.lang.String	getLocalAddr() Returns the IP address of the interface on which the request was received.
java.util.Locale	getLocale() get the locale associated with the request.
java.util.Enumeration	getLocales() get all the locales associated with the request.
java.lang.String	getLocalName() Returns the DNS hostname of the IP interface on which the request was received.
int	getLocalPort() Returns the port number of the interface on which the request was received.
java.lang.String	getParameter(java.lang.String name) Gets the value of a named requestparameter.
java.util.Map	getParameterMap() Gets a Map of all the parameters contained within this request
java.util.Enumeration	getParameterNames() Gets all parameter names.
java.lang.String[]	getParameterValues(java.lang.String name) Gets an array of Strings containing all the request parameter's values whose name matches name.
java.lang.String	getProtocol() Gets the protocol of the request as Proto/Major.Minor ("HTTP/1.1").
java.io.BufferedReader	getReader() Creates an BufferedReader for servlets to read client request data from.
java.lang.String	getRealPath(java.lang.String path) Deprecated. Should use getRealPath from the current ServletContext.
java.lang.String	getRemoteAddr() Gets the ip address of the client that sent the request
java.lang.String	getRemoteHost() Gets the hostname of the client that sent the request.
int	getRemotePort() Returns the IP source port of the client that sent the request.
RequestDispatcher	getRequestDispatcher(java.lang.String path) get a means of dispatching to the specified path.
java.lang.String	getScheme() Gets the scheme of the request as defined by RFC 1783 ("ftp", "http", "gopher", "news").
java.lang.String	getServerName() Get the name of the server receiving the request
int	getServerPort() Gets the portnumber the server reveiving the request is running on.
ServletContext	getServletContext() Returns the context to which this request was last dispatched.
boolean	isAsyncStarted() Indicates whether this request has been put into asynchronous mode.
boolean	isAsyncSupported() Indicates whether asynchronous mode is supported for this request.
boolean	isSecure() has the request arrived under secure conditions? A secure condition might be an encrypted channel, for example SSL.
void	removeAttribute(java.lang.String name) remove the specified attribute.
void	setAttribute(java.lang.String name, java.lang.Object o) Puts a named object into the ServletRequest.
void	setCharacterEncoding(java.lang.String enc) Sets the name of the character encoding used for the body of this request
AsyncContext	startAsync() Put this request into asynchronous mode.
AsyncContext	startAsync(ServletRequest request, ServletResponse response) Put this request into asynchronous mode using the specified request/response pair.

Method Detail

getAttribute

java.lang.Object getAttribute(java.lang.String name)

Gets a named attribute's value. This gives one of the initialization attribute values.

Note that the Servlet 2.1 API Documentation mentions some predefined attribute names, but the Servlet Spec does not mention them. I (MJW) am not sure if they are platform specific (JWS) or not.

Parameters:

name - the attribute name

Returns:

The value of the attribute, null if not found.

getAttributeNames

java.util.Enumeration getAttributeNames()

Gets an Enumeration of all the attribute names.

Returns:

The Enumeration of all attribute names set in this request.

Since:

2.1

getCharacterEncoding

java.lang.String getCharacterEncoding()

Gets the character encoding of the request data.

Returns:

Character encoding or null if the encoding is unavailable

Since:

2.0

setCharacterEncoding

void setCharacterEncoding(java.lang.String enc)
                          throws java.io.UnsupportedEncodingException

Sets the name of the character encoding used for the body of this request

Parameters:

enc - a String containing the name of the character encoding

Throws:

java.io.UnsupportedEncodingException - if the provided name is not a valid encoding scheme

Since:

2.3

getContentLength

int getContentLength()

Gets the size in bytes of the request

Returns:

the number of bytes in the request or -1 if not known

getContentType

java.lang.String getContentType()

Gets the mime type of the request

Returns:

a String containing the mime type of the request or null if not known

getInputStream

ServletInputStream getInputStream()
                                  throws java.io.IOException

Creates an inputstream for servlets to read client request data from.

Returns:

The created InputStreams

Throws:

java.io.IOException - if an i/o related error occured

java.lang.IllegalStateException - if getReader was already called on this request.

See Also:

getReader()

getParameter

java.lang.String getParameter(java.lang.String name)

Gets the value of a named requestparameter. If the parameter can have more than one value getParameterValues should be used. If there are more than one values associated with the parameter this method will only return the first value as return by getParameterValues is returned. see javax.servlet.ServletRequest.getParameterValues()

Parameters:

name - the name of the parameter whose value we want

Returns:

the (first) value of the parameter or null if not present

getParameterNames

java.util.Enumeration getParameterNames()

Gets all parameter names.

Note that the Servlet API 2.1 documentation says that this returns an empty Enumeration if the input stream is empty, but this is not mandated by the Servlet Spec.

Returns:

an enumeration containing all parameter names

getParameterValues

java.lang.String[] getParameterValues(java.lang.String name)

Gets an array of Strings containing all the request parameter's values whose name matches name.

Parameters:

name - the parameter name

Returns:

the array containing all the values or null if not present

getParameterMap

java.util.Map getParameterMap()

Gets a Map of all the parameters contained within this request

Returns:

java.util.Map containing key value pairs of the request parameters, where the key is a String containing the parameter name, and the value is an array of Strings containing the parameter values

Since:

2.3

getProtocol

java.lang.String getProtocol()

Gets the protocol of the request as Proto/Major.Minor ("HTTP/1.1").

Returns:

A string containing the protocol name

getScheme

java.lang.String getScheme()

Gets the scheme of the request as defined by RFC 1783 ("ftp", "http", "gopher", "news").

Returns:

A String containing the scheme

getServerName

java.lang.String getServerName()

Get the name of the server receiving the request

Returns:

The name of the server.

getServerPort

int getServerPort()

Gets the portnumber the server reveiving the request is running on.

Returns:

the portnumber

getReader

java.io.BufferedReader getReader()
                                 throws java.io.IOException

Creates an BufferedReader for servlets to read client request data from.

Returns:

The created BufferedReader

Throws:

java.io.IOException - if an i/o related error occured

java.lang.IllegalStateException - if getInputStream was already called on this request.

java.io.UnsupportedEncodingException - if the character encoding cannot be decoded.

Since:

2.0

See Also:

getInputStream()

getRemoteAddr

java.lang.String getRemoteAddr()

Gets the ip address of the client that sent the request

Returns:

the client's ip address

getRemoteHost

java.lang.String getRemoteHost()

Gets the hostname of the client that sent the request. This is either a fully qualified host name or a string representing the remote IP address.

Returns:

the client's hostname

setAttribute

void setAttribute(java.lang.String name,
                java.lang.Object o)

Puts a named object into the ServletRequest. Can be used to communicate with other servlets if this ServletRequest is passed to another servlet through a RequestDispatcher. The names used must follow the conventions used for naming java packages.

Parameters:

name - - which is used to refer to this object

object - - which should be returned when somebody calls getAttribute(name)

Since:

2.1

See Also:

getAttribute(java.lang.String), RequestDispatcher

removeAttribute

void removeAttribute(java.lang.String name)

remove the specified attribute.

Parameters:

name - the name of the attribute to be removed

Since:

2.1

getLocale

java.util.Locale getLocale()

get the locale associated with the request.

Returns:

the international locale of the request

Since:

2.2

getLocales

java.util.Enumeration getLocales()

get all the locales associated with the request.

Since:

2.2

isSecure

boolean isSecure()

has the request arrived under secure conditions? A secure condition might be an encrypted channel, for example SSL.

Since:

2.2

getRequestDispatcher

RequestDispatcher getRequestDispatcher(java.lang.String path)

get a means of dispatching to the specified path. Relative path resolution is performed.

Parameters:

path - if relative it will be resolved

Returns:

the means if dispatching to the path

Since:

2.2

getRealPath

java.lang.String getRealPath(java.lang.String path)

Deprecated. Should use getRealPath from the current ServletContext.

Translates the given path to the real path on the servers filesystem, using the servers documentroot.

Parameters:

path - the path which requires translating

Returns:

the translated path

See Also:

ServletContext.getRealPath(java.lang.String)

getRemotePort

int getRemotePort()

Returns the IP source port of the client that sent the request.

Since:

2.4

getLocalName

java.lang.String getLocalName()
                              throws java.io.IOException

Returns the DNS hostname of the IP interface on which the request was received.

Throws:

java.io.IOException

Since:

2.4

getLocalAddr

java.lang.String getLocalAddr()
                              throws java.io.IOException

Returns the IP address of the interface on which the request was received.

Throws:

java.io.IOException

Since:

2.4

getLocalPort

int getLocalPort()
                 throws java.io.IOException

Returns the port number of the interface on which the request was received.

Throws:

java.io.IOException

Since:

2.4

getServletContext

ServletContext getServletContext()

Returns the context to which this request was last dispatched.

Since:

3.0

startAsync

AsyncContext startAsync()
                        throws java.lang.IllegalStateException

Put this request into asynchronous mode. The associated response will not be committed until AsyncContext.complete() has been called.

Returns:

the context for the asynchronous operation

Throws:

java.lang.IllegalStateException

Since:

3.0

startAsync

AsyncContext startAsync(ServletRequest request,
                      ServletResponse response)
                        throws java.lang.IllegalStateException

Put this request into asynchronous mode using the specified request/response pair. The associated response will not be committed until AsyncContext.complete() has been called.

Returns:

the context for the asynchronous operation

Throws:

java.lang.IllegalStateException

Since:

3.0

isAsyncStarted

boolean isAsyncStarted()

Indicates whether this request has been put into asynchronous mode.

Since:

3.0

isAsyncSupported

boolean isAsyncSupported()

Indicates whether asynchronous mode is supported for this request.

Since:

3.0

getAsyncContext

AsyncContext getAsyncContext()

Returns the current context for asynchronous operation.

Throws:

java.lang.IllegalStateException - if this request has not been put into asynchronous mode.

Since:

3.0

getDispatcherType

DispatcherType getDispatcherType()

Returns the dispatcher type of this request.

Since:

3.0