org.mortbay.jetty.servlet
Class ServletHttpResponse

java.lang.Object
  org.mortbay.jetty.servlet.ServletHttpResponse

All Implemented Interfaces:

HttpServletResponse, ServletResponse

public class ServletHttpResponse

extends java.lang.Object

implements HttpServletResponse

Servlet Response Wrapper. This class wraps a Jetty HTTP response as a 2.2 Servlet response. Note that this wrapper is not synchronized and if a response is to be operated on by multiple threads, then higher level synchronizations may be required.

Version:

$Id: ServletHttpResponse.java,v 1.64 2005/10/07 11:52:59 gregwilkins Exp $

Author:

Greg Wilkins (gregw)

Field Summary

static int	DISABLED
static int	NO_OUT
static int	OUTPUTSTREAM_OUT
static int	WRITER_OUT

Fields inherited from interface javax.servlet.http.HttpServletResponse

SC_ACCEPTED, SC_BAD_GATEWAY, SC_BAD_REQUEST, SC_CONFLICT, SC_CONTINUE, SC_CREATED, SC_EXPECTATION_FAILED, SC_FORBIDDEN, SC_FOUND, SC_GATEWAY_TIMEOUT, SC_GONE, SC_HTTP_VERSION_NOT_SUPPORTED, SC_INTERNAL_SERVER_ERROR, SC_LENGTH_REQUIRED, SC_METHOD_NOT_ALLOWED, SC_MOVED_PERMANENTLY, SC_MOVED_TEMPORARILY, SC_MULTIPLE_CHOICES, SC_NO_CONTENT, SC_NON_AUTHORITATIVE_INFORMATION, SC_NOT_ACCEPTABLE, SC_NOT_FOUND, SC_NOT_IMPLEMENTED, SC_NOT_MODIFIED, SC_OK, SC_PARTIAL_CONTENT, SC_PAYMENT_REQUIRED, SC_PRECONDITION_FAILED, SC_PROXY_AUTHENTICATION_REQUIRED, SC_REQUEST_ENTITY_TOO_LARGE, SC_REQUEST_TIMEOUT, SC_REQUEST_URI_TOO_LONG, SC_REQUESTED_RANGE_NOT_SATISFIABLE, SC_RESET_CONTENT, SC_SEE_OTHER, SC_SERVICE_UNAVAILABLE, SC_SWITCHING_PROTOCOLS, SC_TEMPORARY_REDIRECT, SC_UNAUTHORIZED, SC_UNSUPPORTED_MEDIA_TYPE, SC_USE_PROXY

Constructor Summary

ServletHttpResponse(ServletHttpRequest request, HttpResponse response)

Method Summary

void	addCookie(Cookie cookie) Adds the specified cookie to the response.
void	addDateHeader(java.lang.String name, long value) 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) Deprecated. As of version 2.1, use encodeRedirectURL(String url) instead
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) Deprecated. As of version 2.1, use encodeURL(String url) instead
java.lang.String	encodeURL(java.lang.String url) Encodes the specified URL by including the session ID in it, or, if encoding is not needed, returns the URL unchanged.
void	flushBuffer() Forces any content in the buffer to be written to the client.
int	getBufferSize() Returns the actual buffer size used for the response.
java.lang.String	getCharacterEncoding() Returns the name of the character encoding (MIME charset) used for the body sent in this response.
java.lang.String	getContentType() Returns the content type used for the MIME body sent in this response.
java.util.Locale	getLocale() Returns the locale specified for this response using the setLocale(java.util.Locale) method.
ServletOutputStream	getOutputStream() Returns a ServletOutputStream suitable for writing binary data in the response.
java.io.PrintWriter	getWriter() Returns a PrintWriter object that can send character text to the client.
boolean	isCommitted() Returns a boolean indicating if the response has been committed.
void	reset() Clears any data that exists in the buffer as well as the status code and headers.
void	resetBuffer() Clears the content of the underlying buffer in the response without clearing headers or status code.
void	sendError(int status) Sends an error response to the client using the specified status code and clearing the buffer.
void	sendError(int status, java.lang.String message) Sends an error response to the client using the specified status.
void	sendRedirect(java.lang.String url) Sends a temporary redirect response to the client using the specified redirect location URL.
void	setBufferSize(int size) Sets the preferred buffer size for the body of the response.
void	setCharacterEncoding(java.lang.String encoding) Sets the character encoding (MIME charset) of the response being sent to the client, for example, to UTF-8.
void	setContentLength(int len) Sets the length of the content body in the response In HTTP servlets, this method sets the HTTP Content-Length header.
void	setContentType(java.lang.String contentType) Sets the content type of the response being sent to the client, if the response has not been committed yet.
void	setDateHeader(java.lang.String name, long value) 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	setLocale(java.util.Locale locale) Sets the locale of the response, setting the headers (including the Content-Type's charset) as appropriate.
void	setStatus(int status) Sets the status code for this response.
void	setStatus(int status, java.lang.String message) Deprecated. As of version 2.1 of the Servlet spec. To set a status code use setStatus(int), to send an error with a description use sendError(int, String). Sets the status code and message for this response.
java.lang.String	toString()
static ServletHttpResponse	unwrap(ServletResponse response) Unwrap a ServletResponse.

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, wait, wait, wait

Field Detail

DISABLED

public static final int DISABLED

See Also:

Constant Field Values

NO_OUT

public static final int NO_OUT

See Also:

Constant Field Values

OUTPUTSTREAM_OUT

public static final int OUTPUTSTREAM_OUT

See Also:

Constant Field Values

WRITER_OUT

public static final int WRITER_OUT

See Also:

Constant Field Values

Constructor Detail

ServletHttpResponse

public ServletHttpResponse(ServletHttpRequest request,
                           HttpResponse response)

Method Detail

isCommitted

public boolean isCommitted()

Description copied from interface: ServletResponse

Returns a boolean indicating if the response has been committed. A commited response has already had its status code and headers written.

Specified by:

isCommitted in interface ServletResponse

Returns:

a boolean indicating if the response has been committed

See Also:

ServletResponse.setBufferSize(int), ServletResponse.getBufferSize(), ServletResponse.flushBuffer(), ServletResponse.reset()

setBufferSize

public void setBufferSize(int size)

Description copied from interface: ServletResponse

Sets the preferred buffer size for the body of the response. The servlet container will use a buffer at least as large as the size requested. The actual buffer size used can be found using getBufferSize.

A larger buffer allows more content to be written before anything is actually sent, thus providing the servlet with more time to set appropriate status codes and headers. 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; if content has been written or the response object has been committed, this method throws an IllegalStateException.

Specified by:

setBufferSize in interface ServletResponse

Parameters:

size - the preferred buffer size

See Also:

ServletResponse.getBufferSize(), ServletResponse.flushBuffer(), ServletResponse.isCommitted(), ServletResponse.reset()

getBufferSize

public int getBufferSize()

Description copied from interface: ServletResponse

Returns the actual buffer size used for the response. If no buffering is used, this method returns 0.

Specified by:

getBufferSize in interface ServletResponse

Returns:

the actual buffer size used

See Also:

ServletResponse.setBufferSize(int), ServletResponse.flushBuffer(), ServletResponse.isCommitted(), ServletResponse.reset()

flushBuffer

public void flushBuffer()
                 throws java.io.IOException

Description copied from interface: ServletResponse

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.

Specified by:

flushBuffer in interface ServletResponse

Throws:

java.io.IOException

See Also:

ServletResponse.setBufferSize(int), ServletResponse.getBufferSize(), ServletResponse.isCommitted(), ServletResponse.reset()

resetBuffer

public void resetBuffer()

Description copied from interface: ServletResponse

Clears the content of the underlying buffer in the response without clearing headers or status code. If the response has been committed, this method throws an IllegalStateException.

Specified by:

resetBuffer in interface ServletResponse

See Also:

ServletResponse.setBufferSize(int), ServletResponse.getBufferSize(), ServletResponse.isCommitted(), ServletResponse.reset()

reset

public void reset()

Description copied from interface: ServletResponse

Clears any data that exists in the buffer as well as the status code and headers. If the response has been committed, this method throws an IllegalStateException.

Specified by:

reset in interface ServletResponse

See Also:

ServletResponse.setBufferSize(int), ServletResponse.getBufferSize(), ServletResponse.flushBuffer(), ServletResponse.isCommitted()

setLocale

public void setLocale(java.util.Locale locale)

Sets the locale of the response, setting the headers (including the Content-Type's charset) as appropriate. This method should be called before a call to getWriter(). By default, the response locale is the default locale for the server.

Specified by:

setLocale in interface ServletResponse

Parameters:

locale - the Locale of the response

See Also:

getLocale()

getLocale

public java.util.Locale getLocale()

Description copied from interface: ServletResponse

Returns the locale specified for this response using the ServletResponse.setLocale(java.util.Locale) method. Calls made to setLocale after the response is committed have no effect. If no locale has been specified, the container's default locale is returned.

Specified by:

getLocale in interface ServletResponse

See Also:

ServletResponse.setLocale(java.util.Locale)

addCookie

public void addCookie(Cookie cookie)

Description copied from interface: HttpServletResponse

Adds the specified cookie to the response. This method can be called multiple times to set more than one cookie.

Specified by:

addCookie in interface HttpServletResponse

Parameters:

cookie - the Cookie to return to the client

containsHeader

public boolean containsHeader(java.lang.String name)

Description copied from interface: HttpServletResponse

Returns a boolean indicating whether the named response header has already been set.

Specified by:

containsHeader in interface HttpServletResponse

Parameters:

name - the header name

Returns:

true if the named response header has already been set; false otherwise

encodeURL

public java.lang.String encodeURL(java.lang.String url)

Description copied from interface: HttpServletResponse

Encodes the specified URL by including the session ID in it, 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.

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.

Specified by:

encodeURL in interface HttpServletResponse

Parameters:

url - the url to be encoded.

Returns:

the encoded URL if encoding is needed; the unchanged URL otherwise.

encodeRedirectURL

public java.lang.String encodeRedirectURL(java.lang.String url)

Description copied from interface: HttpServletResponse

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 separete 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.

Specified by:

encodeRedirectURL in interface HttpServletResponse

Parameters:

url - the url to be encoded.

Returns:

the encoded URL if encoding is needed; the unchanged URL otherwise.

See Also:

HttpServletResponse.sendRedirect(java.lang.String), HttpServletResponse.encodeUrl(java.lang.String)

encodeUrl

public java.lang.String encodeUrl(java.lang.String url)

Deprecated. As of version 2.1, use encodeURL(String url) instead

Specified by:

encodeUrl in interface HttpServletResponse

Parameters:

url - the url to be encoded.

Returns:

the encoded URL if encoding is needed; the unchanged URL otherwise.

encodeRedirectUrl

public java.lang.String encodeRedirectUrl(java.lang.String url)

Deprecated. As of version 2.1, use encodeRedirectURL(String url) instead

Specified by:

encodeRedirectUrl in interface HttpServletResponse

Parameters:

url - the url to be encoded.

Returns:

the encoded URL if encoding is needed; the unchanged URL otherwise.

sendError

public void sendError(int status,
                      java.lang.String message)
               throws java.io.IOException

Description copied from interface: HttpServletResponse

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 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.

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.

Specified by:

sendError in interface HttpServletResponse

Parameters:

status - the error status code

message - the descriptive message

Throws:

java.io.IOException - If an input or output exception occurs

sendError

public void sendError(int status)
               throws java.io.IOException

Description copied from interface: HttpServletResponse

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.

Specified by:

sendError in interface HttpServletResponse

Parameters:

status - the error status code

Throws:

java.io.IOException - If an input or output exception occurs

sendRedirect

public void sendRedirect(java.lang.String url)
                  throws java.io.IOException

Description copied from interface: HttpServletResponse

Sends a temporary redirect response to the client using the specified redirect location URL. 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 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.

Specified by:

sendRedirect in interface HttpServletResponse

Parameters:

url - the redirect location URL

Throws:

java.io.IOException - If an input or output exception occurs

setDateHeader

public void setDateHeader(java.lang.String name,
                          long value)

Description copied from interface: HttpServletResponse

Sets a response header with the given name and date-value. The date is specified in terms of milliseconds since the epoch. If the header had 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.

Specified by:

setDateHeader in interface HttpServletResponse

Parameters:

name - the name of the header to set

value - the assigned date value

See Also:

HttpServletResponse.containsHeader(java.lang.String), HttpServletResponse.addDateHeader(java.lang.String, long)

setHeader

public void setHeader(java.lang.String name,
                      java.lang.String value)

Description copied from interface: HttpServletResponse

Sets a response header with the given name and value. If the header had 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.

Specified by:

setHeader in interface HttpServletResponse

Parameters:

name - the name of the header

value - the header value If it contains octet string, it should be encoded according to RFC 2047 (http://www.ietf.org/rfc/rfc2047.txt)

See Also:

HttpServletResponse.containsHeader(java.lang.String), HttpServletResponse.addHeader(java.lang.String, java.lang.String)

setIntHeader

public void setIntHeader(java.lang.String name,
                         int value)

Description copied from interface: HttpServletResponse

Sets a response header with the given name and integer value. If the header had 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.

Specified by:

setIntHeader in interface HttpServletResponse

Parameters:

name - the name of the header

value - the assigned integer value

See Also:

HttpServletResponse.containsHeader(java.lang.String), HttpServletResponse.addIntHeader(java.lang.String, int)

addDateHeader

public void addDateHeader(java.lang.String name,
                          long value)

Description copied from interface: HttpServletResponse

Adds a response header with the given name and date-value. The date is specified in terms of milliseconds since the epoch. This method allows response headers to have multiple values.

Specified by:

addDateHeader in interface HttpServletResponse

Parameters:

name - the name of the header to set

value - the additional date value

See Also:

HttpServletResponse.setDateHeader(java.lang.String, long)

addHeader

public void addHeader(java.lang.String name,
                      java.lang.String value)

Description copied from interface: HttpServletResponse

Adds a response header with the given name and value. This method allows response headers to have multiple values.

Specified by:

addHeader in interface HttpServletResponse

Parameters:

name - the name of the header

value - the additional header value If it contains octet string, it should be encoded according to RFC 2047 (http://www.ietf.org/rfc/rfc2047.txt)

See Also:

HttpServletResponse.setHeader(java.lang.String, java.lang.String)

addIntHeader

public void addIntHeader(java.lang.String name,
                         int value)

Description copied from interface: HttpServletResponse

Adds a response header with the given name and integer value. This method allows response headers to have multiple values.

Specified by:

addIntHeader in interface HttpServletResponse

Parameters:

name - the name of the header

value - the assigned integer value

See Also:

HttpServletResponse.setIntHeader(java.lang.String, int)

setStatus

public void setStatus(int status)

Description copied from interface: HttpServletResponse

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 SC_MOVED_TEMPORARILY). If there is an error, and the caller wishes to invoke an error-page defined in the web applicaion, the sendError method should be used instead.

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

Specified by:

setStatus in interface HttpServletResponse

Parameters:

status - the status code

See Also:

HttpServletResponse.sendError(int, java.lang.String)

setStatus

public void setStatus(int status,
                      java.lang.String message)

Deprecated. As of version 2.1 of the Servlet spec. To set a status code use setStatus(int), to send an error with a description use sendError(int, String). Sets the status code and message for this response.

Specified by:

setStatus in interface HttpServletResponse

Parameters:

status - the status code

message - the status message

getOutputStream

public ServletOutputStream getOutputStream()

Description copied from interface: ServletResponse

Returns a ServletOutputStream suitable for writing binary data in the response. The servlet container does not encode the binary data.

Calling flush() on the ServletOutputStream commits the response. Either this method or ServletResponse.getWriter() may be called to write the body, not both.

Specified by:

getOutputStream in interface ServletResponse

Returns:

a ServletOutputStream for writing binary data

See Also:

ServletResponse.getWriter()

getWriter

public java.io.PrintWriter getWriter()
                              throws java.io.IOException

Description copied from interface: ServletResponse

Returns a PrintWriter object that can send character text to the client. The PrintWriter uses the character encoding returned by ServletResponse.getCharacterEncoding(). If the response's character encoding has not been specified as described in getCharacterEncoding (i.e., the method just returns the default value ISO-8859-1), getWriter updates it to ISO-8859-1.

Calling flush() on the PrintWriter commits the response.

Either this method or ServletResponse.getOutputStream() may be called to write the body, not both.

Specified by:

getWriter in interface ServletResponse

Returns:

a PrintWriter object that can return character data to the client

Throws:

java.io.IOException - if an input or output exception occurred

See Also:

ServletResponse.getOutputStream(), ServletResponse.setCharacterEncoding(java.lang.String)

setContentLength

public void setContentLength(int len)

Description copied from interface: ServletResponse

Sets the length of the content body in the response In HTTP servlets, this method sets the HTTP Content-Length header.

Specified by:

setContentLength in interface ServletResponse

Parameters:

len - an integer specifying the length of the content being returned to the client; sets the Content-Length header

getContentType

public java.lang.String getContentType()

Description copied from interface: ServletResponse

Returns the content type used for the MIME body sent in this response. The content type proper must have been specified using ServletResponse.setContentType(java.lang.String) before the response is committed. If no content type has been specified, this method returns null. If a content type has been specified and a character encoding has been explicitly or implicitly specified as described in ServletResponse.getCharacterEncoding(), the charset parameter is included in the string returned. If no character encoding has been specified, the charset parameter is omitted.

Specified by:

getContentType in interface ServletResponse

Returns:

a String specifying the content type, for example, text/html; charset=UTF-8, or null

setContentType

public void setContentType(java.lang.String contentType)

Description copied from interface: ServletResponse

Sets the content type of the response being sent to the client, if the response has not been committed yet. The given content type may include a character encoding specification, for example, text/html;charset=UTF-8. The response's character encoding is only set from the given content type if this method is called before getWriter is called.

This method may be called repeatedly to change content type and character encoding. This method has no effect if called after the response has been committed. It does not set the response's character encoding if it is called after getWriter has been called or after the response has been committed.

Containers must communicate the content type and the character encoding used for the servlet response's writer to the client if the protocol provides a way for doing so. In the case of HTTP, the Content-Type header is used.

Specified by:

setContentType in interface ServletResponse

Parameters:

contentType - a String specifying the MIME type of the content

See Also:

ServletResponse.setLocale(java.util.Locale), ServletResponse.setCharacterEncoding(java.lang.String), ServletResponse.getOutputStream(), ServletResponse.getWriter()

setCharacterEncoding

public void setCharacterEncoding(java.lang.String encoding)

Description copied from interface: ServletResponse

Sets the character encoding (MIME charset) of the response being sent to the client, for example, to UTF-8. If the character encoding has already been set by ServletResponse.setContentType(java.lang.String) or ServletResponse.setLocale(java.util.Locale), this method overrides it. Calling ServletResponse.setContentType(java.lang.String) with the String of text/html and calling this method with the String of UTF-8 is equivalent with calling setContentType with the String of text/html; charset=UTF-8.

This method can be called repeatedly to change the character encoding. This method has no effect if it is called after getWriter has been called or after the response has been committed.

Containers must communicate the character encoding used for the servlet response's writer to the client if the protocol provides a way for doing so. In the case of HTTP, the character encoding is communicated as part of the Content-Type header for text media types. Note that the character encoding cannot be communicated via HTTP headers if the servlet does not specify a content type; however, it is still used to encode text written via the servlet response's writer.

Specified by:

setCharacterEncoding in interface ServletResponse

Parameters:

encoding - a String specifying only the character set defined by IANA Character Sets (http://www.iana.org/assignments/character-sets)

See Also:

ServletResponse.setContentType(java.lang.String), ServletResponse.setLocale(java.util.Locale)

getCharacterEncoding

public java.lang.String getCharacterEncoding()

Description copied from interface: ServletResponse

Returns the name of the character encoding (MIME charset) used for the body sent in this response. The character encoding may have been specified explicitly using the ServletResponse.setCharacterEncoding(java.lang.String) or ServletResponse.setContentType(java.lang.String) methods, or implicitly using the ServletResponse.setLocale(java.util.Locale) method. Explicit specifications take precedence over implicit specifications. Calls made to these methods after getWriter has been called or after the response has been committed have no effect on the character encoding. If no character encoding has been specified, ISO-8859-1 is returned.

See RFC 2047 (http://www.ietf.org/rfc/rfc2047.txt) for more information about character encoding and MIME.

Specified by:

getCharacterEncoding in interface ServletResponse

Returns:

a String specifying the name of the character encoding, for example, UTF-8

toString

public java.lang.String toString()

unwrap

public static ServletHttpResponse unwrap(ServletResponse response)

Unwrap a ServletResponse.

Parameters:

response -

Returns:

The core ServletHttpResponse which must be the underlying response object

See Also:

ServletResponseWrapper, HttpServletResponseWrapper