public interface HttpServletResponse extends ServletResponse
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 an HttpServletResponse
object and passes it as an argument to the
servlet's service methods (doGet
, doPost
, etc).
ServletResponse
Modifier and Type | Field and Description |
---|---|
static int |
SC_ACCEPTED
Status code (202) indicating that a request was accepted for processing, but was not completed.
|
static int |
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.
|
static int |
SC_BAD_REQUEST
Status code (400) indicating the request sent by the client was syntactically incorrect.
|
static int |
SC_CONFLICT
Status code (409) indicating that the request could not be completed due to a conflict with the current state of the
resource.
|
static int |
SC_CONTINUE
Status code (100) indicating the client can continue.
|
static int |
SC_CREATED
Status code (201) indicating the request succeeded and created a new resource on the server.
|
static int |
SC_EXPECTATION_FAILED
Status code (417) indicating that the server could not meet the expectation given in the Expect request header.
|
static int |
SC_FORBIDDEN
Status code (403) indicating the server understood the request but refused to fulfill it.
|
static int |
SC_FOUND
Status code (302) indicating that the resource reside temporarily under a different URI.
|
static int |
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.
|
static int |
SC_GONE
Status code (410) indicating that the resource is no longer available at the server and no forwarding address is
known.
|
static int |
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.
|
static int |
SC_INTERNAL_SERVER_ERROR
Status code (500) indicating an error inside the HTTP server which prevented it from fulfilling the request.
|
static int |
SC_LENGTH_REQUIRED
Status code (411) indicating that the request cannot be handled without a defined
Content-Length . |
static int |
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 . |
static int |
SC_MOVED_PERMANENTLY
Status code (301) indicating that the resource has permanently moved to a new location, and that future references
should use a new URI with their requests.
|
static int |
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.
|
static int |
SC_MULTIPLE_CHOICES
Status code (300) indicating that the requested resource corresponds to any one of a set of representations, each
with its own specific location.
|
static int |
SC_NO_CONTENT
Status code (204) indicating that the request succeeded but that there was no new information to return.
|
static int |
SC_NON_AUTHORITATIVE_INFORMATION
Status code (203) indicating that the meta information presented by the client did not originate from the server.
|
static int |
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.
|
static int |
SC_NOT_FOUND
Status code (404) indicating that the requested resource is not available.
|
static int |
SC_NOT_IMPLEMENTED
Status code (501) indicating the HTTP server does not support the functionality needed to fulfill the request.
|
static int |
SC_NOT_MODIFIED
Status code (304) indicating that a conditional GET operation found that the resource was available and not modified.
|
static int |
SC_OK
Status code (200) indicating the request succeeded normally.
|
static int |
SC_PARTIAL_CONTENT
Status code (206) indicating that the server has fulfilled the partial GET request for the resource.
|
static int |
SC_PAYMENT_REQUIRED
Status code (402) reserved for future use.
|
static int |
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.
|
static int |
SC_PROXY_AUTHENTICATION_REQUIRED
Status code (407) indicating that the client MUST first authenticate itself with the proxy.
|
static int |
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.
|
static int |
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.
|
static int |
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. |
static int |
SC_REQUESTED_RANGE_NOT_SATISFIABLE
Status code (416) indicating that the server cannot serve the requested byte range.
|
static int |
SC_RESET_CONTENT
Status code (205) indicating that the agent SHOULD reset the document view which caused the request to be
sent.
|
static int |
SC_SEE_OTHER
Status code (303) indicating that the response to the request can be found under a different URI.
|
static int |
SC_SERVICE_UNAVAILABLE
Status code (503) indicating that the HTTP server is temporarily overloaded, and unable to handle the request.
|
static int |
SC_SWITCHING_PROTOCOLS
Status code (101) indicating the server is switching protocols according to Upgrade header.
|
static int |
SC_TEMPORARY_REDIRECT
Status code (307) indicating that the requested resource resides temporarily under a different URI.
|
static int |
SC_UNAUTHORIZED
Status code (401) indicating that the request requires HTTP authentication.
|
static int |
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.
|
static int |
SC_USE_PROXY
Status code (305) indicating that the requested resource MUST be accessed through the proxy given by the
Location field. |
Modifier and Type | Method and Description |
---|---|
void |
addCookie(Cookie cookie)
Adds the specified cookie to the response.
|
void |
addDateHeader(java.lang.String name,
long date)
Adds a response header with the given name and date-value.
|
void |
addHeader(java.lang.String name,
java.lang.String value)
Adds a response header with the given name and value.
|
void |
addIntHeader(java.lang.String name,
int value)
Adds a response header with the given name and integer value.
|
boolean |
containsHeader(java.lang.String name)
Returns a boolean indicating whether the named response header has already been set.
|
java.lang.String |
encodeRedirectURL(java.lang.String url)
Encodes the specified URL for use in the
sendRedirect method or, if encoding is not needed, returns the
URL unchanged. |
java.lang.String |
encodeURL(java.lang.String url)
Encodes the specified URL by including the session ID, or, if encoding is not needed, returns the URL unchanged.
|
java.lang.String |
getHeader(java.lang.String name)
Gets the value of the response header with the given name.
|
java.util.Collection<java.lang.String> |
getHeaderNames()
Gets the names of the headers of this response.
|
java.util.Collection<java.lang.String> |
getHeaders(java.lang.String name)
Gets the values of the response header with the given name.
|
int |
getStatus()
Gets the current status code of this response.
|
default java.util.function.Supplier<java.util.Map<java.lang.String,java.lang.String>> |
getTrailerFields()
Gets the supplier of trailer headers.
|
void |
sendError(int sc)
Sends an error response to the client using the specified status code and clears the buffer.
|
void |
sendError(int sc,
java.lang.String msg)
Sends an error response to the client using the specified status and clears the buffer.
|
void |
sendRedirect(java.lang.String location)
Sends a temporary redirect response to the client using the specified redirect location URL and clears the buffer.
|
void |
setDateHeader(java.lang.String name,
long date)
Sets a response header with the given name and date-value.
|
void |
setHeader(java.lang.String name,
java.lang.String value)
Sets a response header with the given name and value.
|
void |
setIntHeader(java.lang.String name,
int value)
Sets a response header with the given name and integer value.
|
void |
setStatus(int sc)
Sets the status code for this response.
|
default void |
setTrailerFields(java.util.function.Supplier<java.util.Map<java.lang.String,java.lang.String>> supplier)
Sets the supplier of trailer headers.
|
flushBuffer, getBufferSize, getCharacterEncoding, getContentType, getLocale, getOutputStream, getWriter, isCommitted, reset, resetBuffer, setBufferSize, setCharacterEncoding, setContentLength, setContentLengthLong, setContentType, setLocale
static final int SC_CONTINUE
static final int SC_SWITCHING_PROTOCOLS
static final int SC_OK
static final int SC_CREATED
static final int SC_ACCEPTED
static final int SC_NON_AUTHORITATIVE_INFORMATION
static final int SC_NO_CONTENT
static final int SC_RESET_CONTENT
static final int SC_PARTIAL_CONTENT
static final int SC_MULTIPLE_CHOICES
static final int SC_MOVED_PERMANENTLY
static final int SC_MOVED_TEMPORARILY
static final int SC_FOUND
static final int SC_SEE_OTHER
static final int SC_NOT_MODIFIED
static final int SC_USE_PROXY
Location
field.static final int SC_TEMPORARY_REDIRECT
Location
field in the response.static final int SC_BAD_REQUEST
static final int SC_UNAUTHORIZED
static final int SC_PAYMENT_REQUIRED
static final int SC_FORBIDDEN
static final int SC_NOT_FOUND
static final int SC_METHOD_NOT_ALLOWED
Request-Line
is not allowed for
the resource identified by the Request-URI
.static final int SC_NOT_ACCEPTABLE
static final int SC_PROXY_AUTHENTICATION_REQUIRED
static final int SC_REQUEST_TIMEOUT
static final int SC_CONFLICT
static final int SC_GONE
static final int SC_LENGTH_REQUIRED
Content-Length
.static final int SC_PRECONDITION_FAILED
static final int SC_REQUEST_ENTITY_TOO_LARGE
static final int SC_REQUEST_URI_TOO_LONG
Request-URI
is longer than the server is willing to interpret.static final int SC_UNSUPPORTED_MEDIA_TYPE
static final int SC_REQUESTED_RANGE_NOT_SATISFIABLE
static final int SC_EXPECTATION_FAILED
static final int SC_INTERNAL_SERVER_ERROR
static final int SC_NOT_IMPLEMENTED
static final int SC_BAD_GATEWAY
static final int SC_SERVICE_UNAVAILABLE
static final int SC_GATEWAY_TIMEOUT
static final int SC_HTTP_VERSION_NOT_SUPPORTED
void addCookie(Cookie cookie)
cookie
- the Cookie to return to the clientboolean containsHeader(java.lang.String name)
name
- the header nametrue
if the named response header has already been set; false
otherwisejava.lang.String encodeURL(java.lang.String url)
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.
If the URL is relative, it is always relative to the current HttpServletRequest.
url
- the url to be encoded.java.lang.IllegalArgumentException
- if the url is not validjava.lang.String encodeRedirectURL(java.lang.String url)
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. For example, if the browser supports cookies, or session tracking is turned off, URL encoding is
unnecessary. Because the rules for making this determination can differ from those used to decide whether to encode a
normal link, this method is separated from the encodeURL
method.
All URLs sent to the HttpServletResponse.sendRedirect
method should be run through this method.
Otherwise, URL rewriting cannot be used with browsers which do not support cookies.
If the URL is relative, it is always relative to the current HttpServletRequest.
url
- the url to be encoded.java.lang.IllegalArgumentException
- if the url is not validsendRedirect(java.lang.String)
void sendError(int sc, java.lang.String msg) throws java.io.IOException
Sends an error response to the client using the specified status and clears the buffer. The server defaults to creating the response to look like an HTML-formatted server error page containing the specified message, setting the content type to "text/html". The caller is not responsible for escaping or re-encoding the message to ensure it is safe with respect to the current response encoding and content type. This aspect of safety is the responsibility of the container, as it is generating the error page containing the message. The server will preserve cookies and may clear or update any headers needed to serve the error page as a valid response.
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 suggested msg parameter and the msg parameter will be ignored.
If the response has already been committed, this method throws an IllegalStateException. After using this method, the response should be considered to be committed and should not be written to.
sc
- the error status codemsg
- the descriptive messagejava.io.IOException
- If an input or output exception occursjava.lang.IllegalStateException
- If the response was committedvoid sendError(int sc) throws java.io.IOException
If the response has already been committed, this method throws an IllegalStateException. After using this method, the response should be considered to be committed and should not be written to.
sc
- the error status codejava.io.IOException
- If an input or output exception occursjava.lang.IllegalStateException
- If the response was committed before this method callvoid sendRedirect(java.lang.String location) throws java.io.IOException
SC_FOUND
302 (Found). 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. If the location is relative with two leading
'/' the container interprets it as a network-path reference (see RFC
3986: Uniform Resource Identifier (URI): Generic Syntax, section 4.2 "Relative Reference").
If the response has already been committed, this method throws an IllegalStateException. After using this method, the response should be considered to be committed and should not be written to.
location
- the redirect location URLjava.io.IOException
- If an input or output exception occursjava.lang.IllegalStateException
- If the response was committed or if a partial URL is given and cannot be converted
into a valid URLvoid setDateHeader(java.lang.String name, long date)
containsHeader
method can be used to test for the presence of a header before setting its value.name
- the name of the header to setdate
- the assigned date valuecontainsHeader(java.lang.String)
,
addDateHeader(java.lang.String, long)
void addDateHeader(java.lang.String name, long date)
name
- the name of the header to setdate
- the additional date valuesetDateHeader(java.lang.String, long)
void setHeader(java.lang.String name, java.lang.String value)
containsHeader
method can be used to test for the presence of a header before
setting its value.name
- the name of the headervalue
- the header value If it contains octet string, it should be encoded according to RFC 2047
(http://www.ietf.org/rfc/rfc2047.txt)containsHeader(java.lang.String)
,
addHeader(java.lang.String, java.lang.String)
void addHeader(java.lang.String name, java.lang.String value)
name
- the name of the headervalue
- the additional header value If it contains octet string, it should be encoded according to RFC 2047
(http://www.ietf.org/rfc/rfc2047.txt)setHeader(java.lang.String, java.lang.String)
void setIntHeader(java.lang.String name, int value)
containsHeader
method can be used to test for the presence of a header
before setting its value.name
- the name of the headervalue
- the assigned integer valuecontainsHeader(java.lang.String)
,
addIntHeader(java.lang.String, int)
void addIntHeader(java.lang.String name, int value)
name
- the name of the headervalue
- the assigned integer valuesetIntHeader(java.lang.String, int)
void setStatus(int sc)
This method is used to set the return status code when there is no error (for example, for the SC_OK or SC_MOVED_TEMPORARILY status codes).
If this method is used to set an error code, then the container's error page mechanism will not be triggered. If
there is an error and the caller wishes to invoke an error page defined in the web application, then
sendError(int, java.lang.String)
must be used instead.
This method preserves any cookies and other response headers.
Valid status codes are those in the 2XX, 3XX, 4XX, and 5XX ranges. Other status codes are treated as container specific.
sc
- the status codesendError(int, java.lang.String)
int getStatus()
java.lang.String getHeader(java.lang.String name)
If a response header with the given name exists and contains multiple values, the value that was added first will be returned.
This method considers only response headers set or added via setHeader(java.lang.String, java.lang.String)
, addHeader(java.lang.String, java.lang.String)
,
setDateHeader(java.lang.String, long)
, addDateHeader(java.lang.String, long)
, setIntHeader(java.lang.String, int)
, or addIntHeader(java.lang.String, int)
, respectively.
name
- the name of the response header whose value to returnjava.util.Collection<java.lang.String> getHeaders(java.lang.String name)
This method considers only response headers set or added via setHeader(java.lang.String, java.lang.String)
, addHeader(java.lang.String, java.lang.String)
,
setDateHeader(java.lang.String, long)
, addDateHeader(java.lang.String, long)
, setIntHeader(java.lang.String, int)
, or addIntHeader(java.lang.String, int)
, respectively.
Any changes to the returned Collection
must not affect this HttpServletResponse
.
name
- the name of the response header whose values to returnCollection
of the values of the response header with the given namejava.util.Collection<java.lang.String> getHeaderNames()
This method considers only response headers set or added via setHeader(java.lang.String, java.lang.String)
, addHeader(java.lang.String, java.lang.String)
,
setDateHeader(java.lang.String, long)
, addDateHeader(java.lang.String, long)
, setIntHeader(java.lang.String, int)
, or addIntHeader(java.lang.String, int)
, respectively.
Any changes to the returned Collection
must not affect this HttpServletResponse
.
Collection
of the names of the headers of this responsedefault void setTrailerFields(java.util.function.Supplier<java.util.Map<java.lang.String,java.lang.String>> supplier)
The trailer header field value is defined as a comma-separated list (see Section 3.2.2 and Section 4.1.2 of RFC 7230).
The supplier will be called within the scope of whatever thread/call causes the response content to be completed. Typically this will be any thread calling close() on the output stream or writer.
The trailers that run afoul of the provisions of section 4.1.2 of RFC 7230 are ignored.
The RFC requires the name of every key that is to be in the supplied Map is included in the comma separated list that is the value of the "Trailer" response header. The application is responsible for ensuring this requirement is met. Failure to do so may lead to interoperability failures.
supplier
- the supplier of trailer headersjava.lang.IllegalStateException
- if it is invoked after the response has has been committed, or the trailer is not
supported in the request, for instance, the underlying protocol is HTTP 1.0, or the response is not in chunked
encoding in HTTP 1.1.default java.util.function.Supplier<java.util.Map<java.lang.String,java.lang.String>> getTrailerFields()
Supplier
of trailer headers