Servlet::Http::HttpServletResponse - HTTP servlet response interface

- NAME
- SYNOPSIS
- DESCRIPTION
- FIELDS
- METHODS
- SEE ALSO
- AUTHOR

# NAME

Servlet::Http::HttpServletResponse - HTTP servlet response interface

# SYNOPSIS

      $response->addCookie($cookie);

      $response->addDateHeader($name, $date);

      $response->addHeader($name, $value);

      $bool = $response->containsHeader($name);

      $response->encodeRedirectURL($url);

      $response->encodeURL($url);

      $response->sendError($sc, $msg);

      $response->sendRedirect($location);

      $response->setDateHeader($name, $date);

      $response->setHeader($name, $value);

      $response->setStatus($sc);

# DESCRIPTION

Extends the Servlet::ServletResponse interface to provide HTTP-specific functionality in sending a response. For example, it has methods to access HTTP headers and cookies.

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

# FIELDS

SC_ACCEPTED
  Status code (202) indicating that a request was accepted for processing, but was not completed.

SC_BAD_GATEWAY
  Status code (502) indicating that the HTTP server received an invalid response from a server it consulted when acting as a proxy or gateway.

SC_BAD_REQUEST
  Status code (400) indicating the request sent by the client was syntactically incorrect.

SC_CONFLICT
  Status code (409) indicating that the request could not be completed due to a conflict with the current state of the resource.

SC_CONTINUE
  Status code (100) indicating the client can continue.

SC_CREATED
  Status code (201) indicating the request succeeded and created a new resource on the server.

SC_EXPECTATION_FAILED
  Status code (417) indicating that the server could not meet the expectation given in the Expect request header.

SC_FORBIDDEN
  Status code (403) indicating the server understood the request but refused to fulfill it.

SC_GATEWAY_TIMEOUT
  Status code (504) indicating that the server did not receive a timely response from the upstream server while acting as a gateway or proxy.

SC_GONE
  Status code (410) indicating that the resource is no longer available at the server and no forwarding address is known. This condition SHOULD be considered permanent.

SC_HTTP_VERSION_NOT_SUPPORTED
  Status code (505) indicating that the server does not support or refuses to support the HTTP protocol version that was used in the request message.

SC_INTERNAL_SERER_ERROR
  Status code (500) indicating an error inside the HTTP server which prevented it from fulfilling the request.

SC_LENGTH_REQUIRED
  Status code (411) indicating that the requst cannot be handled without a defined Content-Length.

SC_METHOD_NOT_ALLOWED
  Status code (405) indicating that the method specified in the Request-Line is not allowed for the resource identified by the Request-URI.

SC_MOVED_PERMANENTLY
  Status code (301) indicating that the resource has permanently moved to a new location, and that future references shoud use a new URI with their requests.

SC_MOVED_TEMPORARILY
  Status code (302) indicating that the resource has temporarily moved to another location, but that future references should still use the original URI to access the resource.

SC_MULTIPLE_CHOICES
  Status code (300) indicating that the requested resource corresponds to any one of a set of representations, each with its own specified location.

SC_NO_CONTENT
  Status code (204) indicating that the request succeeded but that there was no new information to return.

SC_NON_AUTHORITATIVE_INFORMATION
  Status code (203) indicating that the meta information presented by the client did not originate from th server.

SC_NOT_ACCEPTABLE
  Status code (406) indicating that the resource identified by the request is only capable of generating response entities which have content characteristics not acceptable according to the Accept headers sent in the request.

SC_NOT_FOUND
  Status code (404) indicating that the requested resource is not available.

SC_NOT_IMPLEMENTED
  Status code (501) indicating that the HTTP server does not support the functionality needed to fulfill the request.

SC_NOT_MODIFIED
  Status code (304) indicating that a conditional GET operation found that the resource was available and not modified.

SC_OK
  Status code (200) indicating the request succeeded normally.

SC_PARTIAL_CONTENT
  Status code (206) indicating that the server has fulfilled the partial GET request for the resource.

SC_PAYMENT_REQUIRED
  Status code (402) reserved for future use.

SC_PRECONDITION_FAILED
  Status code (412) indicating that the precondition given in one or more of the request header fields evaluated to false when it was tested on the server.

SC_PROXY_AUTHENTICATION_REQUIRED
  Status code (407) indicating that the client MUST first authenticate itself with the proxy.

SC_REQUEST_ENTITY_TOO_LARGE
  Status code (413) indicating that the server is refusing to process the request because the request entity is larger than the server is willing or able to process.

SC_REQUEST_TIMEOUT
  Status code (408) indicating that the client did not produce a request within the time that the server was prepared to wait.

SC_REQUEST_URI_TOO_LONG
  Status code (414) indicating that the server is refusing to service the request because the Request-URI is longer than the server is willing to interpret.

SC_REQUESTED_RANGE_NOT_SATISFIABLE
  Status code (416) indicating that the server cannot serve the requested byte range.

SC_RESET_CONTENT
  Status code (205) indicating that the agent SHOULD reset the document view which caused the request to be sent.

SC_SEE_OTHER
  Status code (303) indicating that the response to the request can be found under a different URI.

SC_SERVICE_UNAVAILABLE
  Status code (503) indicating that the HTTP server is temporarily overloaded and unable to handle the reqeust.

SC_SWITCHING_PROTOCOLS
  Status code (101) indicating the server is switching protocols according to the Upgrade header.

SC_UNAUTHORIZED
  Status code (401) indicating that the request requires HTTP authentication.

SC_UNSUPPORTED_MEDIA_TYPE
  Status code (415) indicating that the server is refusing to service the request because the entity of the request is in a format not supported by the requested resource for the requested method.

SC_USE_PROXY
  Status code (305) indicating that the requested resource MUST be accessed through the proxy given by the Location field.

# METHODS

`addCookie($cookie)`
  Adds the specified cookie to the response. This method can be called multiple times to set more than one cookie.

  Parameters:

  $cookie
    the Servlet::Http::Cookie to return to the client

addDateHeader($name, $date)
  Adds a response header with the given name and date-value. The date is specified in terms of seconds since the epoch. This method allows respone headers to have multiple values.

  Parameters:

  $name
    the name of the header to add

  $date
    the additional header value

addHeader($name, $value)
  Adds a response header with the given name and value. This method allows response headers to have multiple values.

  Parameters:

  $name
    the name of the header to add

  $date
    the additional header value

`containsHeader($name)`
  Returns a boolean indicating whether the named response header has already been set.

  Parameters:

  $name
    the name of the header

`encodeRedirectURL($url)`
  Encodes the specified URL for use in the `sendRedirect()` method or, if encoding is not needed, returns the URL unchanged. The implementation of this method includes the logic to determine whether the session ID needs to be encoded in the URL. Because the rules for making this determination can differ from those used to decide whether to encode a normal link, this method is separate from the `encodeURL()` method.

  All URLs sent to the `sendRedirect()` method should be run through this method. Otherwise, URL rewriting cannot be used with browsers which do not support cookies.

  Parameters:

  $url
    the url to be encoded

`encodeURL($url)`
  Encodes the session ID into the specified URL or, if encoding is not needed, returns the URL unchanged. The implementation of this method includes the logic to determine whether the session ID needs to be encoded in the URL. For example, if the borwser supports cookies, or session tracking is turned off, URL encoding is unnecessary.

  For robust session tracking, all URLs emitted by a servlet should be run through this method. Otherwise, URL rewriting cannot be used with browsers which do not support cookies.

  Parameters:

  $url
    the url to be encoded

sendError($sc, [$msg])
  Sends an error response to the client using the specified status code and optional descriptive message, clearing the output buffer. The server defaults to creating the response to look like an HTML-formatted server error page, setting the content type to ``text/html'', leaving cookies and other headers unmodified. If an error-page declaration has been made for the web application corresponding to the status code passed in, it will be served back in preference to the server-generated page.

  After using this method, the response should be considered to be committed and should not be written to.

  Parameters:

  $sc
    the error status code

  msg
    the optional descriptive message; if unspecified, the standard message for the given status code will be used.

  Throws:

  Servlet::Util::IOException
    if an input or output exception occurs

  Servlet::Util::IllegalStateException
    if the response has already been committed

`sendRedirect($location)`
  Sends a temporary redirect response to the client using the specified redirect location URI. This method can accept relative URLs; the servlet container must convert the relative URL to an absolute URL before sending the response to the client. If the location is relative without a leading ``/'' the container interprets it as relative to the current request URI. If the location is relative with a leading ``/'' the container interprets it as relative to the servlet container root.

  After using this method, the response should be considered to be committed and should not be written to.

  Parameters:

  $location
    the redirect location URL

  Throws:

  Servlet::Util::IOException
    if an input or output exception occurs

  Servlet::Util::IllegalStateException
    if the response has already been committed

setDateHeader($name, $date)
  Sets a respone header with the given name and date-value. The date is specified in terms of seconds since the epoch. If the header has already been set, the new value overwrites the previous one. The `containsHeader()` method can be used to test for the presence of a header before setting its value.

  Parameters:

  $name
    the name of the header

  $date
    the header value

setHeader($name, $value)
  Sets a response header with the given name and value. If the header has already been set, the new value overwrites the previous one. The `containsHeader()` method can be used to test for the presence of a header before setting its value.

  Parameters:

  $name
    the name of the header

  $value
    the header value

`setStatus($sc)`
  Sets the status code for this response. This method is used to set the return status code when there is no error (for example, for the status codes SC_OK or SO_MOVED_TEMPORARILY). If there is an error, and the caller wishes to invoke an error-page defined in the web application, the `sendError()` method should be used instead.

  The container clears the output buffer and sets the Location header, preserving cookies and other headers.

  Parameters:

  $sc
    the status code

# SEE ALSO

the Servlet::ServletResponse manpage

# AUTHOR

Brian Moseley, bcm@maz.org