Defines an object to assist a servlet in sending a response to the client.
The servlet container creates a
ServletResponse object and
passes it as an argument to the servlet's
service method.
To send binary data in a MIME body response, use
the
ServletOutputStream returned by
getOutputStream().
To send character data, use the
PrintWriter object
returned by
getWriter(). To mix binary and text data,
for example, to create a multipart response, use a
ServletOutputStream and manage the character sections
manually.
The charset for the MIME body response can be specified with
setContentType(java.lang.String). For example, "text/html; charset=Shift_JIS".
The charset can alternately be set using
setLocale(Locale).
If no charset is specified, ISO-8859-1 will be used.
The
setContentType or
setLocale method
must be called before
getWriter for the charset to
affect the construction of the writer.
See the Internet RFCs such as
RFC 2045 for more information on MIME. Protocols such as SMTP
and HTTP define profiles of MIME, and those standards
are still evolving.
flushBuffer
public void flushBuffer()
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.
setBufferSize(int), getBufferSize(), isCommitted(), reset()
getCharacterEncoding
public java.lang.String getCharacterEncoding()
Returns the name of the charset used for
the MIME body sent in this response.
If no charset has been assigned, it is implicitly
set to
ISO-8859-1 (
Latin-1).
See RFC 2047 (http://ds.internic.net/rfc/rfc2045.txt)
for more information about character encoding and MIME.
- a
String specifying the
name of the charset, for
example, ISO-8859-1
getLocale
public java.util.Locale getLocale()
Returns the locale assigned to the response.
setLocale(Locale)
getWriter
public java.io.PrintWriter getWriter()
Returns a
PrintWriter object that
can send character text to the client.
The character encoding used is the one specified
in the
charset= property of the
setContentType(java.lang.String) method, which must be called
before calling this method for the charset to take effect.
If necessary, the MIME type of the response is
modified to reflect the character encoding used.
Calling flush() on the PrintWriter commits the response.
Either this method or
getOutputStream() may be called
to write the body, not both.
- a
PrintWriter object that
can return character data to the client
getOutputStream(), setContentType(java.lang.String)
isCommitted
public boolean isCommitted()
Returns a boolean indicating if the response has been
committed. A commited response has already had its status
code and headers written.
- a boolean indicating if the response has been
committed
setBufferSize(int), getBufferSize(), flushBuffer(), reset()
resetBuffer
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.
- 2.3
setBufferSize(int), getBufferSize(), isCommitted(), reset()
setBufferSize
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, this method throws an
IllegalStateException.
size - the preferred buffer size
getBufferSize(), flushBuffer(), isCommitted(), reset()
setContentLength
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.
len - an integer specifying the length of the
content being returned to the client; sets
the Content-Length header
setContentType
public void setContentType(java.lang.String type)
Sets the content type of the response being sent to
the client. The content type may include the type of character
encoding used, for example,
text/html; charset=ISO-8859-4.
If obtaining a
PrintWriter, this method should be
called first.
type - a String specifying the MIME
type of the content
getOutputStream(), getWriter()
setLocale
public void setLocale(java.util.Locale loc)
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.
loc - the locale of the response
getLocale()