Top Description Methods
javax.servlet

public Interface ServletRequest

Known Direct Subinterfaces
javax.servlet.http.HttpServletRequest
Known Direct Implementers
javax.servlet.ServletRequestWrapper
Imports
java.io.BufferedReader, .IOException, java.util.Enumeration, .Locale, .Map

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 javax.servlet.http.HttpServletRequest.

Version
$Rev: 46019 $ $Date: 2004-09-14 04:56:06 -0500 (Tue, 14 Sep 2004) $
See Also
javax.servlet.http.HttpServletRequest

Method Summary

Modifier and TypeMethod and Description
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<E>

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 chararacter 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
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.

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 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 the IP address on which the request was received.
getLocalAddr
()

Returns the Internet Protocol (IP) address of 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<E>

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 host name of the Internet Protocol (IP) interface on which the request was received.

public int

Returns:

an integer specifying the port number
getLocalPort
()

Returns the Internet Protocol (IP) port number of 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<K, V>

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<E>

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 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
getRealPath(String path)

Deprecated As of Version 2.1 of the Java Servlet API, use ServletContext#getRealPath instead.
public String

Returns:

a String containing the IP address of the client that sent the request
getRemoteAddr
()

Returns the Internet Protocol (IP) address of the client or last proxy that sent the request.

public String

Returns:

a String containing the fully qualified name of the client
getRemoteHost
()

Returns the fully qualified name of the client or the last proxy that sent the request.

public int
getRemotePort()

Returns the Internet Protocol (IP) source port of the client or last proxy that sent the request.

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 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 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
a String containing the name of the chararacter encoding.
env
)

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

Method Detail

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 javax.servlet.request.X509Certificate can be used to retrieve information on the certificate of the client. Attributes can also be set programatically 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<E> 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<E>

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 the request does not specify a character encoding

Returns:String

a String containing the name of the chararacter 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. For HTTP servlets, same as the value of the CGI variable CONTENT_LENGTH.

Returns:int

an integer containing the length of the request body or -1 if the length is not known

getContentTypeback to summary
public String getContentType()

Returns the MIME type of the body of the request, or null if the type is not known. For HTTP servlets, same as the value of the CGI variable CONTENT_TYPE.

Returns:String

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

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 of the interface on which the request was received.

Returns:String

a String containing the IP address on which the request was received.

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<E> 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<E>

an Enumeration of preferred Locale objects for the client

getLocalNameback to summary
public String getLocalName()

Returns the host name of the Internet Protocol (IP) interface on which the request was received.

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 of the interface on which the request was received.

Returns:int

an integer specifying the 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<K, V> 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<K, V>

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<E> 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<E>

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. For HTTP servlets, the value returned is the same as the value of the CGI variable SERVER_PROTOCOL.

Returns:String

a String containing the protocol name and version number

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
getRealPathback to summary
public String getRealPath(String path)

Deprecated

As of Version 2.1 of the Java Servlet API, use ServletContext#getRealPath instead.

getRemoteAddrback to summary
public 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 variable REMOTE_ADDR.

Returns:String

a String containing the IP address of the client that sent the request

getRemoteHostback to summary
public 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 variable REMOTE_HOST.

Returns:String

a String containing the fully qualified name of the client

getRemotePortback to summary
public int getRemotePort()

Returns the Internet Protocol (IP) source port of the client or last proxy that sent the request.

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.

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
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 is the value of the part before ":" in the Host header, if any, or 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 is the value of the part after ":" in the Host header, if any, or the server port where the client connection was accepted on.

Returns:int

an integer specifying the port number

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. Names beginning with java.*, javax.*, and com.sun.*, are reserved for use by Sun Microsystems.
If the object passed in is null, the effect is the same as calling removeAttribute.

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().

Parameters
env:String

a String containing the name of the chararacter encoding.

Exceptions
UnsupportedEncodingException:
if this is not a valid encoding