HttpServletResponse Class

Used to generate a response to an HTTP request. This class implements the javax.servlet.http.HttpServletResponse interface defined in Version 2.5 of the Java Servlet API.

Constructors

HttpServletResponse( HttpServletRequest request, javax.servlet.http.HttpServletResponse response )

Properties

SC_CONTINUE
Status code (100) indicating the client can continue.
SC_SWITCHING_PROTOCOLS
Status code (101) indicating the server is switching protocols according to Upgrade header.
SC_OK
Status code (200) indicating the request succeeded normally.
SC_CREATED
Status code (201) indicating the request succeeded and created a new resource on the server.
SC_ACCEPTED
Status code (202) indicating that a request was accepted for processing, but was not completed.
SC_NON_AUTHORITATIVE_INFORMATION
Status code (203) indicating that the meta information presented by the client did not originate from the server.
SC_NO_CONTENT
Status code (204) indicating that the request succeeded but that there was no new information to return.
SC_RESET_CONTENT
Status code (205) indicating that the agent SHOULD reset the document view which caused the request to be sent.
SC_PARTIAL_CONTENT
Status code (206) indicating that the server has fulfilled the partial GET request for 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 specific location.
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.
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. This definition is being retained for backwards compatibility. SC_FOUND is now the preferred definition.
SC_FOUND
Status code (302) indicating that the resource reside temporarily under a different URI. Since the redirection might be altered on occasion, the client should continue to use the Request-URI for future requests. (HTTP/1.1) To represent the status code (302), it is recommended to use this variable.
SC_SEE_OTHER
Status code (303) indicating that the response to the request can be found under a different URI.
SC_NOT_MODIFIED
Status code (304) indicating that a conditional GET operation found that the resource was available and not modified.
SC_USE_PROXY
Status code (305) indicating that the requested resource MUST be accessed through the proxy given by the Location field.
SC_TEMPORARY_REDIRECT
Status code (307) indicating that the requested resource resides temporarily under a different URI. The temporary URI SHOULD be given by the Location field in the response.
SC_BAD_REQUEST
Status code (400) indicating the request sent by the client was syntactically incorrect.
SC_UNAUTHORIZED
Status code (401) indicating that the request requires HTTP authentication.
SC_PAYMENT_REQUIRED
Status code (402) reserved for future use.
SC_FORBIDDEN
Status code (403) indicating the server understood the request but refused to fulfill it.
SC_NOT_FOUND
Status code (404) indicating that the requested resource is not available.
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_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_PROXY_AUTHENTICATION_REQUIRED
Status code (407) indicating that the client MUST first authenticate itself with the proxy.
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_CONFLICT
Status code (409) indicating that the request could not be completed due to a conflict with the current state of the resource.
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_LENGTH_REQUIRED
Status code (411) indicating that the request cannot be handled without a defined Content-Length.
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_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_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_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_REQUESTED_RANGE_NOT_SATISFIABLE
Status code (416) indicating that the server cannot serve the requested byte range.
SC_EXPECTATION_FAILED
Status code (417) indicating that the server could not meet the expectation given in the Expect request header.
SC_INTERNAL_SERVER_ERROR
Status code (500) indicating an error inside the HTTP server which prevented it from fulfilling the request.
SC_NOT_IMPLEMENTED
Status code (501) indicating the HTTP server does not support the functionality needed to fulfill the request.
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_SERVICE_UNAVAILABLE
Status code (503) indicating that the HTTP server is temporarily overloaded, and unable to handle the request.
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_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.

Public Methods

addCookie( Cookie cookie ) returns void
Adds the specified cookie to the response.
setContentLength( int contentLength ) returns void
Sets the "Content-Length" in the response header. Note that the "Content-Length" header is set automatically by most of the write() methods. So unless you're writing directly to the ServletOutputStream, you do not need to set this header.
setContentLength( long contentLength ) returns void
Sets the "Content-Length" in the response header. Note that the "Content-Length" header is set automatically by most of the write() methods. So unless you're writing directly to the ServletOutputStream, you do not need to set this header.
getContentLength( ) returns Long
Returns the "Content-Length" defined in the response header. Returns null if the "Content-Length" is not defined or is less than zero.
setContentType( String contentType ) returns void
Used to set/update the "Content-Type" response header (e.g. "text/html; charset=utf-8").
getContentType( ) returns String
Returns the "Content-Type" defined in the response header (e.g. "text/html; charset=utf-8").
setCharacterEncoding( String charset ) returns void
Sets the name of the character encoding used in the response. Default is "UTF-8".
charsetString specifying the character set defined by IANA.
getCharacterEncoding( ) returns String
Returns the name of the character encoding used in the response.
setLocale( java.util.Locale locale ) returns void
Sets the locale of the response. The locale is communicated via the "Content-Language" header and the character encoding in the "Content-Type" header.
getLocale( ) returns java.util.Locale
Returns the locale specified for this response using the setLocale() method.
addHeader( String name, String value ) returns void
Adds a response header with the given name and value. According to spec, http response headers should be allowed to have multiple values. However, this implementation does not currently allow response headers to have multiple values.
setHeader( String name, String value ) returns void
Sets a response header with the given name and value.
getHeader( String name ) returns String
containsHeader( String name ) returns boolean
Returns a boolean indicating whether the named response header has already been set.
setDateHeader( String name, long date ) returns void
Sets a response header with the given name and date-value.
addDateHeader( String name, long date ) returns void
Adds a response header with the given name and date-value. According to spec, http response headers should be allowed to have multiple values. However, this implementation does not currently allow response headers to have multiple values.
setIntHeader( String name, int value ) returns void
Sets a response header with the given name and integer value.
addIntHeader( String name, int value ) returns void
Adds a response header with the given name and integer value. According to spec, http response headers should be allowed to have multiple values. However, this implementation does not currently allow response headers to have multiple values.
setBufferSize( int size ) returns void
Sets the preferred buffer size for the body of the response. A larger buffer allows more content to be sent to the client at a time. A smaller buffer decreases server memory load and allows the client to start receiving data more quickly.

This method must be called before any response body content is written.

getBufferSize( ) returns int
Returns the buffer size used for the response.
setStatus( int sc ) returns void
setStatus( int statusCode, String statusMessage ) returns void
getStatus( ) returns int
sendError( int sc, String msg ) returns void
Sends an error response to the client using the specified status. 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", leaving cookies and other headers unmodified.

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.

sendError( int sc ) returns void
Sends an error response to the client using the specified status code and clearing the buffer.

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.

sendRedirect( String location ) returns void
Sends a temporary redirect response to the client using the specified redirect location URL.
sendRedirect( String location, boolean movedPermanently ) returns void
Sends a temporary or permanent redirect response to the client using the specified redirect location URL.
write( String text, boolean compressOutput ) returns void
Used to write a block of text in the response body. You should only call this method once.
text
compressOutputSpecify whether to gzip compress the text. Note that this option will be applied only if "Accept-Encoding" supports gzip compression.
write( String text ) returns void
Used to write a block of text in the response body. Will automatically try to gzip compress the text if "Accept-Encoding" supports gzip compression. You should only call this method once.
write( byte[] bytes, boolean compressOutput ) returns void
Used to write bytes to the response body. You should only call this method once.
bytesInput byte array
compressOutputSpecify whether to gzip compress the byte array. Note that this option will be applied only if "Accept-Encoding" supports gzip compression. Do not use this option if your bytes are already gzip compressed.
write( byte[] bytes ) returns void
Used to write bytes to the response body. Will automatically try to compress the byte array if "Accept-Encoding" supports gzip compression. You should only call this method once.
write( java.io.File file, String contentType, boolean useCache ) returns void
Used to write contents of a file into the response body. Automatically compresses the file content if the client supports gzip compression. You should only call this method once.
write( java.io.File file, String fileName, String contentType, boolean useCache ) returns void
Used to write contents of a file into the response body. Automatically compresses the file content if the client supports gzip compression. You should only call this method once.
file
fileNameOptional file name used in the "Content-Disposition" header. If the fileName is null, the "Content-Disposition" header will not be set by this method.
contentType
useCache
write( ByteBuffer content ) returns void
write( java.io.InputStream inputStream, boolean compressOutput ) returns void
Used to transfer bytes from an input stream to the response body.
inputStreamjava.io.InputStream
compressOutputSpecify whether to gzip compress the byte array. Note that this option will be applied only if "Accept-Encoding" supports gzip compression. Do not use this option if your bytes are already gzip compressed.
getOutputStream( ) returns ServletOutputStream
Returns an output stream for writing the body of an http response. Automatically encrypts the data if the connection is SSL/TLS encrypted. Note that by default, if the request header includes a keep-alive directive, the response header will include a keep-alive response. As such, you must explicitely set the content length, set the "Connection" header to "Close", or chunk the output using chunked encoding. Example:
      //IMPORTANT: Set response headers before getting the output stream!
        response.setContentLength(54674);

      //Get output stream
        java.io.OutputStream outputStream = response.getOutputStream();

      //Transfer bytes from an input stream to the output stream
        byte[] b = new byte[1024];
        int x=0;
        while ( (x = inputStream.read(b)) != -1) {
            outputStream.write(b,0,x);
        }

      //Close the input and output streams
        outputStream.close();
        inputStream.close();    
getWriter( ) returns java.io.PrintWriter
Returns a PrintWriter object that can send character text to the client.
getHeader( ) returns String
Returns the raw HTTP response header.
toString( ) returns String
Returns the raw HTTP response header.
reset( ) returns void
Clears the status code and headers. This method is called automatically after each new http request to free up server resources. You do not need to call this method explicitly from your application.
flushBuffer( ) returns void
Forces any content in the buffer to be written to the client. A call to this method automatically commits the response, meaning the status code and headers will be written. This method is called automatically after each http request to free up server resources. You do not need to call this method explicitly from your application.
resetBuffer( ) returns void
According to spec, this method is supposed to clear the content buffer. However, this implementation doesn't use a content buffer. All content is written immediately.
isCommitted( ) returns boolean
Returns a boolean indicating if the response has been committed. A committed response has already had its status code and headers written.
encodeURL( String url ) returns String
According to spec, this method is supposed to encode the specified URL by including the session ID in it, or, if encoding is not needed, returns the URL unchanged. This is important for browsers that don't support cookies. In our case, sessions are maintained using cookies so we return the URL unchanged.
encodeRedirectURL( String url ) returns String
According to spec, this method is supposed to encode 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 logic to determine whether the session ID needs to be encoded in the URL. This is important for browsers that don't support cookies. In our case, sessions are maintained using cookies so we return the URL unchanged.
encodeUrl( String url ) returns String
encodeRedirectUrl( String url ) returns String