HttpServletRequest (Java Servlet API 3.1.0 API)

All Superinterfaces:

ServletRequest

All Known Implementing Classes:

HttpServletRequestWrapper
```
public interface HttpServletRequest
extends ServletRequest
```
Extends the 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

Field Summary

Fields
Modifier and Type	Field and Description
`static String`	`BASIC_AUTH` String identifier for Basic authentication.
`static String`	`CLIENT_CERT_AUTH` String identifier for Client Certificate authentication.
`static String`	`DIGEST_AUTH` String identifier for Digest authentication.
`static String`	`FORM_AUTH` String identifier for Form authentication.

Method Summary

Methods
Modifier and Type	Method and Description
`boolean`	`authenticate(HttpServletResponse response)` Use the container login mechanism configured for the `ServletContext` to authenticate the user making this request.
`String`	`changeSessionId()` Change the session id of the current session associated with this request and return the new session id.
`String`	`getAuthType()` Returns the name of the authentication scheme used to protect the servlet.
`String`	`getContextPath()` Returns the portion of the request URI that indicates the context of the request.
`Cookie[]`	`getCookies()` Returns an array containing all of the `Cookie` objects the client sent with this request.
`long`	`getDateHeader(String name)` Returns the value of the specified request header as a `long` value that represents a `Date` object.
`String`	`getHeader(String name)` Returns the value of the specified request header as a `String`.
`Enumeration<String>`	`getHeaderNames()` Returns an enumeration of all the header names this request contains.
`Enumeration<String>`	`getHeaders(String name)` Returns all the values of the specified request header as an `Enumeration` of `String` objects.
`int`	`getIntHeader(String name)` Returns the value of the specified request header as an `int`.
`String`	`getMethod()` Returns the name of the HTTP method with which this request was made, for example, GET, POST, or PUT.
`Part`	`getPart(String name)` Gets the `Part` with the given name.
`Collection<Part>`	`getParts()` Gets all the `Part` components of this request, provided that it is of type `multipart/form-data`.
`String`	`getPathInfo()` Returns any extra path information associated with the URL the client sent when it made this request.
`String`	`getPathTranslated()` Returns any extra path information after the servlet name but before the query string, and translates it to a real path.
`String`	`getQueryString()` Returns the query string that is contained in the request URL after the path.
`String`	`getRemoteUser()` Returns the login of the user making this request, if the user has been authenticated, or `null` if the user has not been authenticated.
`String`	`getRequestedSessionId()` Returns the session ID specified by the client.
`String`	`getRequestURI()` 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.
`StringBuffer`	`getRequestURL()` Reconstructs the URL the client used to make the request.
`String`	`getServletPath()` Returns the part of this request's URL that calls the servlet.
`HttpSession`	`getSession()` Returns the current session associated with this request, or if the request does not have a session, creates one.
`HttpSession`	`getSession(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.
`Principal`	`getUserPrincipal()` Returns a `java.security.Principal` object containing the name of the current authenticated user.
`boolean`	`isRequestedSessionIdFromCookie()` Checks whether the requested session ID came in as a cookie.
`boolean`	`isRequestedSessionIdFromUrl()` Deprecated. As of Version 2.1 of the Java Servlet API, use `isRequestedSessionIdFromURL()` instead.
`boolean`	`isRequestedSessionIdFromURL()` Checks whether the requested session ID came in as part of the request URL.
`boolean`	`isRequestedSessionIdValid()` Checks whether the requested session ID is still valid.
`boolean`	`isUserInRole(String role)` Returns a boolean indicating whether the authenticated user is included in the specified logical "role".
`void`	`login(String username, String password)` Validate the provided username and password in the password validation realm used by the web container login mechanism configured for the `ServletContext`.
`void`	`logout()` Establish `null` as the value returned when `getUserPrincipal`, `getRemoteUser`, and `getAuthType` is called on the request.
`<T extends HttpUpgradeHandler> T`	`upgrade(Class<T> handlerClass)` Create an instance of `HttpUpgradeHandler` for an given class and uses it for the http protocol upgrade processing.

- Field Detail
  - BASIC_AUTH
```
static final String BASIC_AUTH
```
    String identifier for Basic authentication. Value "BASIC"
    
    See Also:
    Constant Field Values
  - FORM_AUTH
```
static final String FORM_AUTH
```
    String identifier for Form authentication. Value "FORM"
    
    See Also:
    Constant Field Values
  - CLIENT_CERT_AUTH
```
static final String CLIENT_CERT_AUTH
```
    String identifier for Client Certificate authentication. Value "CLIENT_CERT"
    
    See Also:
    Constant Field Values
  - DIGEST_AUTH
```
static final String DIGEST_AUTH
```
    String identifier for Digest authentication. Value "DIGEST"
    
    See Also:
    Constant Field Values
- Method Detail
  - getAuthType
```
String getAuthType()
```
    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.
    
    Returns:
    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.
  - getCookies
```
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.
    
    Returns:
    an array of all the Cookies included with this request, or null if the request has no cookies
  - getDateHeader
```
long getDateHeader(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.
    
    Parameters:
    name - a String specifying the name of the header
    
    Returns:
    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
    
    Throws:
    
    IllegalArgumentException - If the header value can't be converted to a date
  - getHeader
```
String getHeader(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.
    
    Parameters:
    name - a String specifying the header name
    
    Returns:
    a String containing the value of the requested header, or null if the request does not have a header of that name
  - getHeaders
```
Enumeration<String> getHeaders(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.
    
    Parameters:
    name - a String specifying the header name
    
    Returns:
    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
  - getHeaderNames
```
Enumeration<String> getHeaderNames()
```
    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
    
    Returns:
    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
  - getIntHeader
```
int getIntHeader(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.
    
    Parameters:
    name - a String specifying the name of a request header
    
    Returns:
    an integer expressing the value of the request header or -1 if the request doesn't have a header of this name
    
    Throws:
    
    NumberFormatException - If the header value can't be converted to an int
  - getMethod
```
String getMethod()
```
    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.
    
    Returns:
    a String specifying the name of the method with which this request was made
  - getPathInfo
```
String getPathInfo()
```
    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.
    
    Returns:
    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
  - getPathTranslated
```
String getPathTranslated()
```
    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.
    
    Returns:
    a String specifying the real path, or null if the URL does not have any extra path information
  - getContextPath
```
String getContextPath()
```
    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.
    It is possible that a servlet container may match a context by more than one context path. In such cases this method will return the actual context path used by the request and it may differ from the path returned by the ServletContext.getContextPath() method. The context path returned by ServletContext.getContextPath() should be considered as the prime or preferred context path of the application.
    
    Returns:
    a String specifying the portion of the request URI that indicates the context of the request
    See Also:
    ServletContext.getContextPath()
  - getQueryString
```
String getQueryString()
```
    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.
    
    Returns:
    a String containing the query string or null if the URL contains no query string. The value is not decoded by the container.
  - getRemoteUser
```
String getRemoteUser()
```
    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.
    
    Returns:
    a String specifying the login of the user making this request, or null if the user login is not known
  - isUserInRole
```
boolean isUserInRole(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.
    The role name “*” should never be used as an argument in calling isUserInRole. Any call to isUserInRole with “*” must return false. If the role-name of the security-role to be tested is “**”, and the application has NOT declared an application security-role with role-name “**”, isUserInRole must only return true if the user has been authenticated; that is, only when getRemoteUser() and getUserPrincipal() would both return a non-null value. Otherwise, the container must check the user for membership in the application role.
    
    Parameters:
    role - a String specifying the name of the role
    
    Returns:
    a boolean indicating whether the user making this request belongs to a given role; false if the user has not been authenticated
  - getUserPrincipal
```
Principal getUserPrincipal()
```
    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.
    
    Returns:
    a java.security.Principal containing the name of the user making this request; null if the user has not been authenticated
  - getRequestedSessionId
```
String getRequestedSessionId()
```
    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.
    
    Returns:
    a String specifying the session ID, or null if the request did not specify a session ID
    See Also:
    isRequestedSessionIdValid()
  - getRequestURI
```
String getRequestURI()
```
    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 HttpUtils.getRequestURL(javax.servlet.http.HttpServletRequest).
    
    Returns:
    a String containing the part of the URL from the protocol name up to the query string
    See Also:
    HttpUtils.getRequestURL(javax.servlet.http.HttpServletRequest)
  - getRequestURL
```
StringBuffer getRequestURL()
```
    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.
    If this request has been forwarded using RequestDispatcher.forward(javax.servlet.ServletRequest, javax.servlet.ServletResponse), the server path in the reconstructed URL must reflect the path used to obtain the RequestDispatcher, and not the server path specified by the client.
    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.
    
    Returns:
    a StringBuffer object containing the reconstructed URL
  - getServletPath
```
String getServletPath()
```
    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.
    
    Returns:
    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.
  - getSession
```
HttpSession getSession(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.
    
    Parameters:
    create - true to create a new session for this request if necessary; false to return null if there's no current session
    
    Returns:
    the HttpSession associated with this request or null if create is false and the request has no valid session
    See Also:
    getSession()
  - getSession
```
HttpSession getSession()
```
    Returns the current session associated with this request, or if the request does not have a session, creates one.
    
    Returns:
    the HttpSession associated with this request
    See Also:
    getSession(boolean)
  - changeSessionId
```
String changeSessionId()
```
    Change the session id of the current session associated with this request and return the new session id.
    
    Returns:
    the new session id
    
    Throws:
    
    IllegalStateException - if there is no session associated with the request
    Since:
    
    Servlet 3.1
  - isRequestedSessionIdValid
```
boolean isRequestedSessionIdValid()
```
    Checks whether the requested session ID is still valid.
    If the client did not specify any session ID, this method returns false.
    
    Returns:
    true if this request has an id for a valid session in the current session context; false otherwise
    See Also:
    getRequestedSessionId(), getSession(boolean), HttpSessionContext
  - isRequestedSessionIdFromCookie
```
boolean isRequestedSessionIdFromCookie()
```
    Checks whether the requested session ID came in as a cookie.
    
    Returns:
    true if the session ID came in as a cookie; otherwise, false
    See Also:
    getSession(boolean)
  - isRequestedSessionIdFromURL
```
boolean isRequestedSessionIdFromURL()
```
    Checks whether the requested session ID came in as part of the request URL.
    
    Returns:
    true if the session ID came in as part of a URL; otherwise, false
    See Also:
    getSession(boolean)
  - isRequestedSessionIdFromUrl
```
boolean isRequestedSessionIdFromUrl()
```
    Deprecated. As of Version 2.1 of the Java Servlet API, use isRequestedSessionIdFromURL() instead.
  - authenticate
```
boolean authenticate(HttpServletResponse response)
                     throws IOException,
                            ServletException
```
    Use the container login mechanism configured for the ServletContext to authenticate the user making this request.
    This method may modify and commit the argument HttpServletResponse.
    
    Parameters:
    response - The HttpServletResponse associated with this HttpServletRequest
    
    Returns:
    true when non-null values were or have been established as the values returned by getUserPrincipal, getRemoteUser, and getAuthType. Return false if authentication is incomplete and the underlying login mechanism has committed, in the response, the message (e.g., challenge) and HTTP status code to be returned to the user.
    
    Throws:
    
    IOException - if an input or output error occurred while reading from this request or writing to the given response
    
    IllegalStateException - if the login mechanism attempted to modify the response and it was already committed
    
    ServletException - if the authentication failed and the caller is responsible for handling the error (i.e., the underlying login mechanism did NOT establish the message and HTTP status code to be returned to the user)
    Since:
    
    Servlet 3.0
  - login
```
void login(String username,
         String password)
           throws ServletException
```
    Validate the provided username and password in the password validation realm used by the web container login mechanism configured for the ServletContext.
    This method returns without throwing a ServletException when the login mechanism configured for the ServletContext supports username password validation, and when, at the time of the call to login, the identity of the caller of the request had not been established (i.e, all of getUserPrincipal, getRemoteUser, and getAuthType return null), and when validation of the provided credentials is successful. Otherwise, this method throws a ServletException as described below.
    When this method returns without throwing an exception, it must have established non-null values as the values returned by getUserPrincipal, getRemoteUser, and getAuthType.
    
    Parameters:
    username - The String value corresponding to the login identifier of the user.
    password - The password String corresponding to the identified user.
    
    Throws:
    
    ServletException - if the configured login mechanism does not support username password authentication, or if a non-null caller identity had already been established (prior to the call to login), or if validation of the provided username and password fails.
    Since:
    
    Servlet 3.0
  - logout
```
void logout()
            throws ServletException
```
    Establish null as the value returned when getUserPrincipal, getRemoteUser, and getAuthType is called on the request.
    
    Throws:
    
    ServletException - if logout fails
    Since:
    
    Servlet 3.0
  - getParts
```
Collection<Part> getParts()
                          throws IOException,
                                 ServletException
```
    Gets all the Part components of this request, provided that it is of type multipart/form-data.
    If this request is of type multipart/form-data, but does not contain any Part components, the returned Collection will be empty.
    Any changes to the returned Collection must not affect this HttpServletRequest.
    
    Returns:
    a (possibly empty) Collection of the Part components of this request
    
    Throws:
    
    IOException - if an I/O error occurred during the retrieval of the Part components of this request
    
    ServletException - if this request is not of type multipart/form-data
    
    IllegalStateException - if the request body is larger than maxRequestSize, or any Part in the request is larger than maxFileSize, or there is no @MultipartConfig or multipart-config in deployment descriptors
    Since:
    
    Servlet 3.0
    
    See Also:
    MultipartConfig.maxFileSize(), MultipartConfig.maxRequestSize()
  - getPart
```
Part getPart(String name)
             throws IOException,
                    ServletException
```
    Gets the Part with the given name.
    
    Parameters:
    name - the name of the requested Part
    
    Returns:
    The Part with the given name, or null if this request is of type multipart/form-data, but does not contain the requested Part
    
    Throws:
    
    IOException - if an I/O error occurred during the retrieval of the requested Part
    
    ServletException - if this request is not of type multipart/form-data
    
    IllegalStateException - if the request body is larger than maxRequestSize, or any Part in the request is larger than maxFileSize, or there is no @MultipartConfig or multipart-config in deployment descriptors
    Since:
    
    Servlet 3.0
    
    See Also:
    MultipartConfig.maxFileSize(), MultipartConfig.maxRequestSize()
  - upgrade
```
<T extends HttpUpgradeHandler> T upgrade(Class<T> handlerClass)
                                     throws IOException,
                                            ServletException
```
    Create an instance of HttpUpgradeHandler for an given class and uses it for the http protocol upgrade processing.
    
    Parameters:
    handlerClass - The HttpUpgradeHandler class used for the upgrade.
    
    Returns:
    an instance of the HttpUpgradeHandler
    
    Throws:
    
    IOException - if an I/O error occurred during the upgrade
    
    ServletException - if the given handlerClass fails to be instantiated
    Since:
    
    Servlet 3.1
    
    See Also:
    HttpUpgradeHandler, WebConnection

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

Interface HttpServletRequest

Field Summary

Method Summary

Methods inherited from interface javax.servlet.ServletRequest

Field Detail

BASIC_AUTH

FORM_AUTH

CLIENT_CERT_AUTH

DIGEST_AUTH

Method Detail

getAuthType

getCookies

getDateHeader

getHeader

getHeaders

getHeaderNames

getIntHeader

getMethod

getPathInfo

getPathTranslated

getContextPath

getQueryString

getRemoteUser

isUserInRole

getUserPrincipal

getRequestedSessionId

getRequestURI

getRequestURL

getServletPath

getSession

getSession

changeSessionId

isRequestedSessionIdValid

isRequestedSessionIdFromCookie

isRequestedSessionIdFromURL

isRequestedSessionIdFromUrl

authenticate

login

logout

getParts

getPart

upgrade