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HttpServletRequest.javaAPI DocApache Tomcat 6.0.1419504Fri Jul 20 04:20:34 BST 2007javax.servlet.http

HttpServletRequest

public interface HttpServletRequest implements ServletRequest
Extends the {@link javax.servlet.ServletRequest} interface to provide request information for HTTP servlets.

The servlet container creates an HttpServletRequest object and passes it as an argument to the servlet's service methods (doGet, doPost, etc).

author
Various
version
$Version$

Fields Summary
public static final String
BASIC_AUTH
String identifier for Basic authentication. Value "BASIC"
public static final String
FORM_AUTH
String identifier for Form authentication. Value "FORM"
public static final String
CLIENT_CERT_AUTH
String identifier for Client Certificate authentication. Value "CLIENT_CERT"
public static final String
DIGEST_AUTH
String identifier for Digest authentication. Value "DIGEST"
Constructors Summary
Methods Summary
public java.lang.StringgetAuthType()
Returns the name of the authentication scheme used to protect the servlet. All servlet containers support basic, form and client certificate authentication, and may additionally support digest authentication. If the servlet is not authenticated null is returned.

Same as the value of the CGI variable AUTH_TYPE.

return
one of the static members BASIC_AUTH, FORM_AUTH, CLIENT_CERT_AUTH, DIGEST_AUTH (suitable for == comparison) or the container-specific string indicating the authentication scheme, or null if the request was not authenticated.

public java.lang.StringgetContextPath()
Returns the portion of the request URI that indicates the context of the request. The context path always comes first in a request URI. The path starts with a "/" character but does not end with a "/" character. For servlets in the default (root) context, this method returns "". The container does not decode this string.

return
a String specifying the portion of the request URI that indicates the context of the request

public javax.servlet.http.Cookie[]getCookies()
Returns an array containing all of the Cookie objects the client sent with this request. This method returns null if no cookies were sent.

return
an array of all the Cookies included with this request, or null if the request has no cookies

public longgetDateHeader(java.lang.String name)
Returns the value of the specified request header as a long value that represents a Date object. Use this method with headers that contain dates, such as If-Modified-Since.

The date is returned as the number of milliseconds since January 1, 1970 GMT. The header name is case insensitive.

If the request did not have a header of the specified name, this method returns -1. If the header can't be converted to a date, the method throws an IllegalArgumentException.

param
name a String specifying the name of the header
return
a long value representing the date specified in the header expressed as the number of milliseconds since January 1, 1970 GMT, or -1 if the named header was not included with the request
exception
IllegalArgumentException If the header value can't be converted to a date

public java.lang.StringgetHeader(java.lang.String name)
Returns the value of the specified request header as a String. If the request did not include a header of the specified name, this method returns null. If there are multiple headers with the same name, this method returns the first head in the request. The header name is case insensitive. You can use this method with any request header.

param
name a String specifying the header name
return
a String containing the value of the requested header, or null if the request does not have a header of that name

public java.util.EnumerationgetHeaderNames()
Returns an enumeration of all the header names this request contains. If the request has no headers, this method returns an empty enumeration.

Some servlet containers do not allow servlets to access headers using this method, in which case this method returns null

return
an enumeration of all the header names sent with this request; if the request has no headers, an empty enumeration; if the servlet container does not allow servlets to use this method, null

public java.util.EnumerationgetHeaders(java.lang.String name)
Returns all the values of the specified request header as an Enumeration of String objects.

Some headers, such as Accept-Language can be sent by clients as several headers each with a different value rather than sending the header as a comma separated list.

If the request did not include any headers of the specified name, this method returns an empty Enumeration. The header name is case insensitive. You can use this method with any request header.

param
name a String specifying the header name
return
an Enumeration containing the values of the requested header. If the request does not have any headers of that name return an empty enumeration. If the container does not allow access to header information, return null

public intgetIntHeader(java.lang.String name)
Returns the value of the specified request header as an int. If the request does not have a header of the specified name, this method returns -1. If the header cannot be converted to an integer, this method throws a NumberFormatException.

The header name is case insensitive.

param
name a String specifying the name of a request header
return
an integer expressing the value of the request header or -1 if the request doesn't have a header of this name
exception
NumberFormatException If the header value can't be converted to an int

public java.lang.StringgetMethod()
Returns the name of the HTTP method with which this request was made, for example, GET, POST, or PUT. Same as the value of the CGI variable REQUEST_METHOD.

return
a String specifying the name of the method with which this request was made

public java.lang.StringgetPathInfo()
Returns any extra path information associated with the URL the client sent when it made this request. The extra path information follows the servlet path but precedes the query string and will start with a "/" character.

This method returns null if there was no extra path information.

Same as the value of the CGI variable PATH_INFO.

return
a String, decoded by the web container, specifying extra path information that comes after the servlet path but before the query string in the request URL; or null if the URL does not have any extra path information

public java.lang.StringgetPathTranslated()
Returns any extra path information after the servlet name but before the query string, and translates it to a real path. Same as the value of the CGI variable PATH_TRANSLATED.

If the URL does not have any extra path information, this method returns null or the servlet container cannot translate the virtual path to a real path for any reason (such as when the web application is executed from an archive). The web container does not decode this string.

return
a String specifying the real path, or null if the URL does not have any extra path information

public java.lang.StringgetQueryString()
Returns the query string that is contained in the request URL after the path. This method returns null if the URL does not have a query string. Same as the value of the CGI variable QUERY_STRING.

return
a String containing the query string or null if the URL contains no query string. The value is not decoded by the container.

public java.lang.StringgetRemoteUser()
Returns the login of the user making this request, if the user has been authenticated, or null if the user has not been authenticated. Whether the user name is sent with each subsequent request depends on the browser and type of authentication. Same as the value of the CGI variable REMOTE_USER.

return
a String specifying the login of the user making this request, or null if the user login is not known

public java.lang.StringgetRequestURI()
Returns the part of this request's URL from the protocol name up to the query string in the first line of the HTTP request. The web container does not decode this String. For example:
First line of HTTP request Returned Value
POST /some/path.html HTTP/1.1/some/path.html
GET http://foo.bar/a.html HTTP/1.0 /a.html
HEAD /xyz?a=b HTTP/1.1/xyz

To reconstruct an URL with a scheme and host, use {@link HttpUtils#getRequestURL}.

return
a String containing the part of the URL from the protocol name up to the query string
see
HttpUtils#getRequestURL

public java.lang.StringBuffergetRequestURL()
Reconstructs the URL the client used to make the request. The returned URL contains a protocol, server name, port number, and server path, but it does not include query string parameters.

Because this method returns a StringBuffer, not a string, you can modify the URL easily, for example, to append query parameters.

This method is useful for creating redirect messages and for reporting errors.

return
a StringBuffer object containing the reconstructed URL

public java.lang.StringgetRequestedSessionId()
Returns the session ID specified by the client. This may not be the same as the ID of the current valid session for this request. If the client did not specify a session ID, this method returns null.

return
a String specifying the session ID, or null if the request did not specify a session ID
see
#isRequestedSessionIdValid

public java.lang.StringgetServletPath()
Returns the part of this request's URL that calls the servlet. This path starts with a "/" character and includes either the servlet name or a path to the servlet, but does not include any extra path information or a query string. Same as the value of the CGI variable SCRIPT_NAME.

This method will return an empty string ("") if the servlet used to process this request was matched using the "/*" pattern.

return
a String containing the name or path of the servlet being called, as specified in the request URL, decoded, or an empty string if the servlet used to process the request is matched using the "/*" pattern.

public javax.servlet.http.HttpSessiongetSession(boolean create)
Returns the current HttpSession associated with this request or, if there is no current session and create is true, returns a new session.

If create is false and the request has no valid HttpSession, this method returns null.

To make sure the session is properly maintained, you must call this method before the response is committed. If the container is using cookies to maintain session integrity and is asked to create a new session when the response is committed, an IllegalStateException is thrown.

param
create true to create a new session for this request if necessary; false to return null if there's no current session
return
the HttpSession associated with this request or null if create is false and the request has no valid session
see
#getSession()

public javax.servlet.http.HttpSessiongetSession()
Returns the current session associated with this request, or if the request does not have a session, creates one.

return
the HttpSession associated with this request
see
#getSession(boolean)

public java.security.PrincipalgetUserPrincipal()
Returns a java.security.Principal object containing the name of the current authenticated user. If the user has not been authenticated, the method returns null.

return
a java.security.Principal containing the name of the user making this request; null if the user has not been authenticated

public booleanisRequestedSessionIdFromCookie()
Checks whether the requested session ID came in as a cookie.

return
true if the session ID came in as a cookie; otherwise, false
see
#getSession

public booleanisRequestedSessionIdFromURL()
Checks whether the requested session ID came in as part of the request URL.

return
true if the session ID came in as part of a URL; otherwise, false
see
#getSession

public booleanisRequestedSessionIdFromUrl()

deprecated
As of Version 2.1 of the Java Servlet API, use {@link #isRequestedSessionIdFromURL} instead.

public booleanisRequestedSessionIdValid()
Checks whether the requested session ID is still valid.

return
true if this request has an id for a valid session in the current session context; false otherwise
see
#getRequestedSessionId
see
#getSession
see
HttpSessionContext

public booleanisUserInRole(java.lang.String role)
Returns a boolean indicating whether the authenticated user is included in the specified logical "role". Roles and role membership can be defined using deployment descriptors. If the user has not been authenticated, the method returns false.

param
role a String specifying the name of the role
return
a boolean indicating whether the user making this request belongs to a given role; false if the user has not been authenticated