public interface ServletResponse
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 explicitly using the
 setCharacterEncoding(java.lang.String) and setContentType(java.lang.String) methods, or
 implicitly using the setLocale(java.util.Locale) method. Explicit specifications take
 precedence over implicit specifications. If no charset is specified,
 ISO-8859-1 will be used. The setCharacterEncoding,
 setContentType, or setLocale method must be called
 before getWriter and before committing the response for the
 character encoding to be used.
 
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.
ServletOutputStream| Modifier and Type | Method and Description | 
|---|---|
| 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  ServletOutputStreamsuitable for writing binary data in
 the response. | 
| java.io.PrintWriter | getWriter()Returns a  PrintWriterobject 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 | setBufferSize(int size)Sets the preferred buffer size for the body of the response. | 
| void | setCharacterEncoding(java.lang.String charset)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 type)Sets the content type of the response being sent to the client, if the
 response has not been committed yet. | 
| void | setLocale(java.util.Locale loc)Sets the locale of the response, if the response has not been committed
 yet. | 
java.lang.String getCharacterEncoding()
setCharacterEncoding(java.lang.String) or
 setContentType(java.lang.String) methods, or implicitly using the
 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.
String specifying the name of the character
         encoding, for example, UTF-8java.lang.String getContentType()
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 getCharacterEncoding(), the charset
 parameter is included in the string returned. If no character encoding
 has been specified, the charset parameter is omitted.String specifying the content type, for example,
         text/html; charset=UTF-8, or nullServletOutputStream getOutputStream() throws java.io.IOException
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.
ServletOutputStream for writing binary datajava.lang.IllegalStateException - if the getWriter method has been called on
                this responsejava.io.IOException - if an input or output exception occurredgetWriter()java.io.PrintWriter getWriter()
                              throws java.io.IOException
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.
PrintWriter object that can return character data
         to the clientjava.io.UnsupportedEncodingException - if the character encoding returned by
                getCharacterEncoding cannot be usedjava.lang.IllegalStateException - if the getOutputStream method has already
                been called for this response objectjava.io.IOException - if an input or output exception occurredgetOutputStream(), 
setCharacterEncoding(java.lang.String)void setCharacterEncoding(java.lang.String charset)
setContentType(java.lang.String) or setLocale(java.util.Locale), this method
 overrides it. Calling 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.
charset - a String specifying only the character set defined by IANA
            Character Sets
            (http://www.iana.org/assignments/character-sets)#setLocalevoid setContentLength(int len)
len - an integer specifying the length of the content being returned
            to the client; sets the Content-Length headervoid setContentType(java.lang.String type)
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.
type - a String specifying the MIME type of the contentsetLocale(java.util.Locale), 
setCharacterEncoding(java.lang.String), 
getOutputStream(), 
getWriter()void setBufferSize(int size)
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.
size - the preferred buffer sizejava.lang.IllegalStateException - if this method is called after content has been writtengetBufferSize(), 
flushBuffer(), 
isCommitted(), 
reset()int getBufferSize()
setBufferSize(int), 
flushBuffer(), 
isCommitted(), 
reset()void flushBuffer()
                 throws java.io.IOException
java.io.IOException - if an I/O occurs during the flushing of the responsesetBufferSize(int), 
getBufferSize(), 
isCommitted(), 
reset()void resetBuffer()
IllegalStateException.setBufferSize(int), 
getBufferSize(), 
isCommitted(), 
reset()boolean isCommitted()
setBufferSize(int), 
getBufferSize(), 
flushBuffer(), 
reset()void reset()
IllegalStateException.java.lang.IllegalStateException - if the response has already been committedsetBufferSize(int), 
getBufferSize(), 
flushBuffer(), 
isCommitted()void setLocale(java.util.Locale loc)
setContentType(java.lang.String) or setCharacterEncoding(java.lang.String),
 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(java.lang.String) has been called with a charset
 specification, after setCharacterEncoding(java.lang.String) 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.
loc - the locale of the responsegetLocale(), 
setContentType(java.lang.String), 
setCharacterEncoding(java.lang.String)java.util.Locale getLocale()
setLocale(java.util.Locale) method. Calls made to setLocale after the
 response is committed have no effect.setLocale(java.util.Locale) method. If no locale has been specified, the
          container's default locale is returned.setLocale(java.util.Locale)Copyright © 2000-2020 Apache Software Foundation. All Rights Reserved.