public  void flushBuffer() throws IOException
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.

 public int getBufferSize()
Returns the actual buffer size used for the response.  If no buffering
is used, this method returns 0.

 public String getCharacterEncoding()
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 #setCharacterEncoding  or
#setContentType  methods, or implicitly using the
#setLocale  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.

 public String getContentType()
Returns the content type used for the MIME body
sent in this response. The content type proper must
have been specified using #setContentType 
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 #getCharacterEncoding ,
the charset parameter is included in the string returned.
If no character encoding has been specified, the
charset parameter is omitted.

 public Locale getLocale()
Returns the locale specified for this response
using the #setLocale  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.

 public ServletOutputStream getOutputStream() throws IOException
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 #getWriter  may 
be called to write the body, not both.

 public PrintWriter getWriter() throws IOException
Returns a PrintWriter object that
can send character text to the client.
The PrintWriter uses the character
encoding returned by #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 #getOutputStream  may be called
to write the body, not both.

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

 public  void reset()
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.

 public  void resetBuffer()
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.

 public  void setBufferSize(int size)
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.

 public  void setCharacterEncoding(String charset)
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
#setContentType  or #setLocale ,
this method overrides it.
Calling #setContentType  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.

 public  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.

 public  void setContentType(String type)
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.

 public  void setLocale(Locale loc)
Sets the locale of the response, if the response has not been
committed yet. It also sets the response's character encoding
appropriately for the locale, if the character encoding has not
been explicitly set using #setContentType  or
#setCharacterEncoding , getWriter hasn't
been called yet, and the response hasn't been committed yet.
If the deployment descriptor contains a 
locale-encoding-mapping-list element, and that
element provides a mapping for the given locale, that mapping
is used. Otherwise, the mapping from locale to character
encoding is container dependent.
This method may be called repeatedly to change locale and
character encoding. The 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 #setContentType 
has been called with a charset specification, after
#setCharacterEncoding  has been called, after
getWriter has been called, or after the response
has been committed.
Containers must communicate the locale 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 locale is
communicated via the Content-Language header,
the character encoding 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.