java/jakarta/servlet/ServletResponse.java - tomcat - Git at Google

 /*
  * Licensed to the Apache Software Foundation (ASF) under one or more
  * contributor license agreements.  See the NOTICE file distributed with
  * this work for additional information regarding copyright ownership.
  * The ASF licenses this file to You under the Apache License, Version 2.0
  * (the "License"); you may not use this file except in compliance with
  * the License.  You may obtain a copy of the License at
  *
  *     http://www.apache.org/licenses/LICENSE-2.0
  *
  * Unless required by applicable law or agreed to in writing, software
  * distributed under the License is distributed on an "AS IS" BASIS,
  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
 package jakarta.servlet;

 import java.io.IOException;
 import java.io.PrintWriter;
 import java.nio.charset.Charset;
 import java.util.Locale;

 /**
  * Defines an object to assist a servlet in sending a response to the client. The servlet container creates a
  * <code>ServletResponse</code> object and passes it as an argument to the servlet's <code>service</code> method.
  * <p>
  * To send binary data in a MIME body response, use the {@link ServletOutputStream} returned by
  * {@link #getOutputStream}. To send character data, use the <code>PrintWriter</code> object returned by
  * {@link #getWriter}. To mix binary and text data, for example, to create a multipart response, use a
  * <code>ServletOutputStream</code> and manage the character sections manually.
  * <p>
  * The charset for the MIME body response can be specified explicitly or implicitly. The priority order for specifying
  * the response body is:
  * <ol>
  * <li>explicitly per request using {@link #setCharacterEncoding} and {@link #setContentType}</li>
  * <li>implicitly per request using {@link #setLocale}</li>
  * <li>per web application via the deployment descriptor or
  * {@link ServletContext#setRequestCharacterEncoding(String)}</li>
  * <li>container default via vendor specific configuration</li>
  * <li>ISO-8859-1</li>
  * </ol>
  * The <code>setCharacterEncoding</code>, <code>setContentType</code>, or <code>setLocale</code> method must be called
  * before <code>getWriter</code> and before committing the response for the character encoding to be used.
  * <p>
  * See the Internet RFCs such as <a href="http://www.ietf.org/rfc/rfc2045.txt"> RFC 2045</a> for more information on
  * MIME. Protocols such as SMTP and HTTP define profiles of MIME, and those standards are still evolving.
  *
  * @see ServletOutputStream
  */
 public interface ServletResponse {

     /**
      * Returns the name of the character encoding (MIME charset) used for the body sent in this response. The charset
      * for the MIME body response can be specified explicitly or implicitly. The priority order for specifying the
      * response body is:
      * <ol>
      * <li>explicitly per request using {@link #setCharacterEncoding} and {@link #setContentType}</li>
      * <li>implicitly per request using {@link #setLocale}</li>
      * <li>per web application via the deployment descriptor or
      * {@link ServletContext#setRequestCharacterEncoding(String)}</li>
      * <li>container default via vendor specific configuration</li>
      * <li>ISO-8859-1</li>
      * </ol>
      * Calls made to {@link #setCharacterEncoding}, {@link #setContentType} or {@link #setLocale} after
      * <code>getWriter</code> has been called or after the response has been committed have no effect on the character
      * encoding. If no character encoding has been specified, <code>ISO-8859-1</code> is returned.
      * <p>
      * See <a href="http://www.ietf.org/rfc/rfc2047.txt">RFC 2047</a> for more information about character encoding and
      * MIME.
      *
      * @return a <code>String</code> specifying the name of the character encoding, for example, <code>UTF-8</code>
      */
     String getCharacterEncoding();

     /**
      * Returns the content type used for the MIME body sent in this response. The content type proper must have been
      * specified using {@link #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 {@link #getCharacterEncoding}, the charset parameter is included in the
      * string returned. If no character encoding has been specified, the charset parameter is omitted.
      *
      * @return a <code>String</code> specifying the content type, for example, <code>text/html; charset=UTF-8</code>, or
      *             null
      *
      * @since Servlet 2.4
      */
     String getContentType();

     /**
      * Returns a {@link ServletOutputStream} suitable for writing binary data in the response. The servlet container
      * does not encode the binary data.
      * <p>
      * Calling flush() on the ServletOutputStream commits the response. Either this method or {@link #getWriter} may be
      * called to write the body, not both.
      *
      * @return a {@link ServletOutputStream} for writing binary data
      *
      * @exception IllegalStateException if the <code>getWriter</code> method has been called on this response
      * @exception IOException           if an input or output exception occurred
      *
      * @see #getWriter
      */
     ServletOutputStream getOutputStream() throws IOException;

     /**
      * Returns a <code>PrintWriter</code> object that can send character text to the client. The
      * <code>PrintWriter</code> uses the character encoding returned by {@link #getCharacterEncoding}. If the response's
      * character encoding has not been specified as described in <code>getCharacterEncoding</code> (i.e., the method
      * just returns the default value <code>ISO-8859-1</code>), <code>getWriter</code> updates it to
      * <code>ISO-8859-1</code>.
      * <p>
      * Calling flush() on the <code>PrintWriter</code> commits the response.
      * <p>
      * Either this method or {@link #getOutputStream} may be called to write the body, not both.
      *
      * @return a <code>PrintWriter</code> object that can return character data to the client
      *
      * @exception java.io.UnsupportedEncodingException if the character encoding returned by
      *                                                     <code>getCharacterEncoding</code> cannot be used
      * @exception IllegalStateException                if the <code>getOutputStream</code> method has already been
      *                                                     called for this response object
      * @exception IOException                          if an input or output exception occurred
      *
      * @see #getOutputStream
      * @see #setCharacterEncoding
      */
     PrintWriter getWriter() throws IOException;

     /**
      * 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 container default, ServletContext default,
      * {@link #setCharacterEncoding(Charset)}, {@link #setContentType} or {@link #setLocale}, this method overrides it.
      * Calling {@link #setContentType} with the <code>String</code> of <code>text/html</code> and calling this method
      * with the <code>String</code> of <code>UTF-8</code> is equivalent with calling <code>setContentType</code> with
      * the <code>String</code> of <code>text/html; charset=UTF-8</code>.
      * <p>
      * This method can be called repeatedly to change the character encoding. This method has no effect if it is called
      * after <code>getWriter</code> has been called or after the response has been committed.
      * <p>
      * 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
      * <code>Content-Type</code> 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.
      *
      * @param charset a String specifying only the character set defined by
      *                    <a href="http://www.iana.org/assignments/character-sets">IANA Character Sets</a>
      *
      * @see #setContentType #setLocale
      * @see #setCharacterEncoding(Charset)
      *
      * @since Servlet 2.4
      */
     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 container default, ServletContext default,
      * {@link #setCharacterEncoding(String)}, {@link #setContentType} or {@link #setLocale}, this method overrides it.
      * Calling {@link #setContentType} with the <code>String</code> of <code>text/html</code> and calling this method
      * with the <code>StandardCharsets.UTF-8</code> is equivalent with calling <code>setContentType</code> with the
      * <code>String</code> of <code>text/html; charset=UTF-8</code>.
      * <p>
      * This method can be called repeatedly to change the character encoding. This method has no effect if it is called
      * after <code>getWriter</code> has been called or after the response has been committed.
      * <p>
      * 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
      * <code>Content-Type</code> 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.
      *
      * @param encoding The encoding to use or {@code null}
      *
      * @see #setContentType #setLocale
      * @see #setCharacterEncoding(String)
      *
      * @since Servlet 6.1
      */
     default void setCharacterEncoding(Charset encoding) {
         if (encoding == null) {
             setCharacterEncoding((String) null);
         } else {
             setCharacterEncoding(encoding.name());
         }
     }

     /**
      * Sets the length of the content body in the response In HTTP servlets, this method sets the HTTP Content-Length
      * header.
      *
      * @param len an integer specifying the length of the content being returned to the client; sets the Content-Length
      *                header
      */
     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.
      *
      * @param length an integer specifying the length of the content being returned to the client; sets the
      *                   Content-Length header
      *
      * @since Servlet 3.1
      */
     void setContentLengthLong(long length);

     /**
      * 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,
      * <code>text/html;charset=UTF-8</code>. The response's character encoding is only set from the given content type
      * if this method is called before <code>getWriter</code> is called.
      * <p>
      * 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 <code>getWriter</code> has been called or after the response has been committed.
      * <p>
      * 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 <code>Content-Type</code> header
      * is used.
      *
      * @param type a <code>String</code> specifying the MIME type of the content
      *
      * @see #setLocale
      * @see #setCharacterEncoding
      * @see #getOutputStream
      * @see #getWriter
      */
     void setContentType(String type);

     /**
      * 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 <code>getBufferSize</code>.
      * <p>
      * 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.
      * <p>
      * 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 <code>IllegalStateException</code>.
      *
      * @param size the preferred buffer size
      *
      * @exception IllegalStateException if this method is called after content has been written
      *
      * @see #getBufferSize
      * @see #flushBuffer
      * @see #isCommitted
      * @see #reset
      */
     void setBufferSize(int size);

     /**
      * Returns the actual buffer size used for the response. If no buffering is used, this method returns 0.
      *
      * @return the actual buffer size used
      *
      * @see #setBufferSize
      * @see #flushBuffer
      * @see #isCommitted
      * @see #reset
      */
     int getBufferSize();

     /**
      * 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.
      *
      * @throws IOException if an I/O occurs during the flushing of the response
      *
      * @see #setBufferSize
      * @see #getBufferSize
      * @see #isCommitted
      * @see #reset
      */
     void flushBuffer() throws IOException;

     /**
      * 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 <code>IllegalStateException</code>.
      *
      * @see #setBufferSize
      * @see #getBufferSize
      * @see #isCommitted
      * @see #reset
      *
      * @since Servlet 2.3
      */
     void resetBuffer();

     /**
      * Returns a boolean indicating if the response has been committed. A committed response has already had its status
      * code and headers written.
      *
      * @return a boolean indicating if the response has been committed
      *
      * @see #setBufferSize
      * @see #getBufferSize
      * @see #flushBuffer
      * @see #reset
      */
     boolean isCommitted();

     /**
      * 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 <code>IllegalStateException</code>.
      *
      * @exception IllegalStateException if the response has already been committed
      *
      * @see #setBufferSize
      * @see #getBufferSize
      * @see #flushBuffer
      * @see #isCommitted
      */
     void reset();

     /**
      * 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
      * {@link #setContentType}, {@link #setCharacterEncoding(String)} or {@link #setCharacterEncoding(Charset)},
      * <code>getWriter</code> hasn't been called yet, and the response hasn't been committed yet. If the deployment
      * descriptor contains a <code>locale-encoding-mapping-list</code> 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.
      * <p>
      * 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
      * {@link #setContentType} has been called with a charset specification, after {@link #setCharacterEncoding} has
      * been called, after <code>getWriter</code> has been called, or after the response has been committed.
      * <p>
      * 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
      * <code>Content-Language</code> header, the character encoding as part of the <code>Content-Type</code> 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.
      *
      * @param loc the locale of the response
      *
      * @see #getLocale
      * @see #setContentType
      * @see #setCharacterEncoding(String)
      * @see #setCharacterEncoding(Charset)
      */
     void setLocale(Locale loc);

     /**
      * Returns the locale specified for this response using the {@link #setLocale} method. Calls made to
      * <code>setLocale</code> after the response is committed have no effect.
      *
      * @return The locale specified for this response using the {@link #setLocale} method. If no locale has been
      *             specified, the container's default locale is returned.
      *
      * @see #setLocale
      */
     Locale getLocale();

 }
	/*
	* Licensed to the Apache Software Foundation (ASF) under one or more
	* contributor license agreements. See the NOTICE file distributed with
	* this work for additional information regarding copyright ownership.
	* The ASF licenses this file to You under the Apache License, Version 2.0
	* (the "License"); you may not use this file except in compliance with
	* the License. You may obtain a copy of the License at
	*
	* http://www.apache.org/licenses/LICENSE-2.0
	*
	* Unless required by applicable law or agreed to in writing, software
	* distributed under the License is distributed on an "AS IS" BASIS,
	* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
	* See the License for the specific language governing permissions and
	* limitations under the License.
	*/
	package jakarta.servlet;

	import java.io.IOException;
	import java.io.PrintWriter;
	import java.nio.charset.Charset;
	import java.util.Locale;

	/**
	* Defines an object to assist a servlet in sending a response to the client. The servlet container creates a
	* <code>ServletResponse</code> object and passes it as an argument to the servlet's <code>service</code> method.
	* <p>
	* To send binary data in a MIME body response, use the {@link ServletOutputStream} returned by
	* {@link #getOutputStream}. To send character data, use the <code>PrintWriter</code> object returned by
	* {@link #getWriter}. To mix binary and text data, for example, to create a multipart response, use a
	* <code>ServletOutputStream</code> and manage the character sections manually.
	* <p>
	* The charset for the MIME body response can be specified explicitly or implicitly. The priority order for specifying
	* the response body is:
	* <ol>
	* <li>explicitly per request using {@link #setCharacterEncoding} and {@link #setContentType}</li>
	* <li>implicitly per request using {@link #setLocale}</li>
	* <li>per web application via the deployment descriptor or
	* {@link ServletContext#setRequestCharacterEncoding(String)}</li>
	* <li>container default via vendor specific configuration</li>
	* <li>ISO-8859-1</li>
	* </ol>
	* The <code>setCharacterEncoding</code>, <code>setContentType</code>, or <code>setLocale</code> method must be called
	* before <code>getWriter</code> and before committing the response for the character encoding to be used.
	* <p>
	* See the Internet RFCs such as <a href="http://www.ietf.org/rfc/rfc2045.txt"> RFC 2045</a> for more information on
	* MIME. Protocols such as SMTP and HTTP define profiles of MIME, and those standards are still evolving.
	*
	* @see ServletOutputStream
	*/
	public interface ServletResponse {

	/**
	* Returns the name of the character encoding (MIME charset) used for the body sent in this response. The charset
	* for the MIME body response can be specified explicitly or implicitly. The priority order for specifying the
	* response body is:
	* <ol>
	* <li>explicitly per request using {@link #setCharacterEncoding} and {@link #setContentType}</li>
	* <li>implicitly per request using {@link #setLocale}</li>
	* <li>per web application via the deployment descriptor or
	* {@link ServletContext#setRequestCharacterEncoding(String)}</li>
	* <li>container default via vendor specific configuration</li>
	* <li>ISO-8859-1</li>
	* </ol>
	* Calls made to {@link #setCharacterEncoding}, {@link #setContentType} or {@link #setLocale} after
	* <code>getWriter</code> has been called or after the response has been committed have no effect on the character
	* encoding. If no character encoding has been specified, <code>ISO-8859-1</code> is returned.
	* <p>
	* See <a href="http://www.ietf.org/rfc/rfc2047.txt">RFC 2047</a> for more information about character encoding and
	* MIME.
	*
	* @return a <code>String</code> specifying the name of the character encoding, for example, <code>UTF-8</code>
	*/
	String getCharacterEncoding();

	/**
	* Returns the content type used for the MIME body sent in this response. The content type proper must have been
	* specified using {@link #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 {@link #getCharacterEncoding}, the charset parameter is included in the
	* string returned. If no character encoding has been specified, the charset parameter is omitted.
	*
	* @return a <code>String</code> specifying the content type, for example, <code>text/html; charset=UTF-8</code>, or
	* null
	*
	* @since Servlet 2.4
	*/
	String getContentType();

	/**
	* Returns a {@link ServletOutputStream} suitable for writing binary data in the response. The servlet container
	* does not encode the binary data.
	* <p>
	* Calling flush() on the ServletOutputStream commits the response. Either this method or {@link #getWriter} may be
	* called to write the body, not both.
	*
	* @return a {@link ServletOutputStream} for writing binary data
	*
	* @exception IllegalStateException if the <code>getWriter</code> method has been called on this response
	* @exception IOException if an input or output exception occurred
	*
	* @see #getWriter
	*/
	ServletOutputStream getOutputStream() throws IOException;

	/**
	* Returns a <code>PrintWriter</code> object that can send character text to the client. The
	* <code>PrintWriter</code> uses the character encoding returned by {@link #getCharacterEncoding}. If the response's
	* character encoding has not been specified as described in <code>getCharacterEncoding</code> (i.e., the method
	* just returns the default value <code>ISO-8859-1</code>), <code>getWriter</code> updates it to
	* <code>ISO-8859-1</code>.
	* <p>
	* Calling flush() on the <code>PrintWriter</code> commits the response.
	* <p>
	* Either this method or {@link #getOutputStream} may be called to write the body, not both.
	*
	* @return a <code>PrintWriter</code> object that can return character data to the client
	*
	* @exception java.io.UnsupportedEncodingException if the character encoding returned by
	* <code>getCharacterEncoding</code> cannot be used
	* @exception IllegalStateException if the <code>getOutputStream</code> method has already been
	* called for this response object
	* @exception IOException if an input or output exception occurred
	*
	* @see #getOutputStream
	* @see #setCharacterEncoding
	*/
	PrintWriter getWriter() throws IOException;

	/**
	* 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 container default, ServletContext default,
	* {@link #setCharacterEncoding(Charset)}, {@link #setContentType} or {@link #setLocale}, this method overrides it.
	* Calling {@link #setContentType} with the <code>String</code> of <code>text/html</code> and calling this method
	* with the <code>String</code> of <code>UTF-8</code> is equivalent with calling <code>setContentType</code> with
	* the <code>String</code> of <code>text/html; charset=UTF-8</code>.
	* <p>
	* This method can be called repeatedly to change the character encoding. This method has no effect if it is called
	* after <code>getWriter</code> has been called or after the response has been committed.
	* <p>
	* 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
	* <code>Content-Type</code> 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.
	*
	* @param charset a String specifying only the character set defined by
	* <a href="http://www.iana.org/assignments/character-sets">IANA Character Sets</a>
	*
	* @see #setContentType #setLocale
	* @see #setCharacterEncoding(Charset)
	*
	* @since Servlet 2.4
	*/
	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 container default, ServletContext default,
	* {@link #setCharacterEncoding(String)}, {@link #setContentType} or {@link #setLocale}, this method overrides it.
	* Calling {@link #setContentType} with the <code>String</code> of <code>text/html</code> and calling this method
	* with the <code>StandardCharsets.UTF-8</code> is equivalent with calling <code>setContentType</code> with the
	* <code>String</code> of <code>text/html; charset=UTF-8</code>.
	* <p>
	* This method can be called repeatedly to change the character encoding. This method has no effect if it is called
	* after <code>getWriter</code> has been called or after the response has been committed.
	* <p>
	* 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
	* <code>Content-Type</code> 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.
	*
	* @param encoding The encoding to use or {@code null}
	*
	* @see #setContentType #setLocale
	* @see #setCharacterEncoding(String)
	*
	* @since Servlet 6.1
	*/
	default void setCharacterEncoding(Charset encoding) {
	if (encoding == null) {
	setCharacterEncoding((String) null);
	} else {
	setCharacterEncoding(encoding.name());
	}
	}

	/**
	* Sets the length of the content body in the response In HTTP servlets, this method sets the HTTP Content-Length
	* header.
	*
	* @param len an integer specifying the length of the content being returned to the client; sets the Content-Length
	* header
	*/
	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.
	*
	* @param length an integer specifying the length of the content being returned to the client; sets the
	* Content-Length header
	*
	* @since Servlet 3.1
	*/
	void setContentLengthLong(long length);

	/**
	* 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,
	* <code>text/html;charset=UTF-8</code>. The response's character encoding is only set from the given content type
	* if this method is called before <code>getWriter</code> is called.
	* <p>
	* 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 <code>getWriter</code> has been called or after the response has been committed.
	* <p>
	* 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 <code>Content-Type</code> header
	* is used.
	*
	* @param type a <code>String</code> specifying the MIME type of the content
	*
	* @see #setLocale
	* @see #setCharacterEncoding
	* @see #getOutputStream
	* @see #getWriter
	*/
	void setContentType(String type);

	/**
	* 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 <code>getBufferSize</code>.
	* <p>
	* 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.
	* <p>
	* 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 <code>IllegalStateException</code>.
	*
	* @param size the preferred buffer size
	*
	* @exception IllegalStateException if this method is called after content has been written
	*
	* @see #getBufferSize
	* @see #flushBuffer
	* @see #isCommitted
	* @see #reset
	*/
	void setBufferSize(int size);

	/**
	* Returns the actual buffer size used for the response. If no buffering is used, this method returns 0.
	*
	* @return the actual buffer size used
	*
	* @see #setBufferSize
	* @see #flushBuffer
	* @see #isCommitted
	* @see #reset
	*/
	int getBufferSize();

	/**
	* 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.
	*
	* @throws IOException if an I/O occurs during the flushing of the response
	*
	* @see #setBufferSize
	* @see #getBufferSize
	* @see #isCommitted
	* @see #reset
	*/
	void flushBuffer() throws IOException;

	/**
	* 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 <code>IllegalStateException</code>.
	*
	* @see #setBufferSize
	* @see #getBufferSize
	* @see #isCommitted
	* @see #reset
	*
	* @since Servlet 2.3
	*/
	void resetBuffer();

	/**
	* Returns a boolean indicating if the response has been committed. A committed response has already had its status
	* code and headers written.
	*
	* @return a boolean indicating if the response has been committed
	*
	* @see #setBufferSize
	* @see #getBufferSize
	* @see #flushBuffer
	* @see #reset
	*/
	boolean isCommitted();

	/**
	* 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 <code>IllegalStateException</code>.
	*
	* @exception IllegalStateException if the response has already been committed
	*
	* @see #setBufferSize
	* @see #getBufferSize
	* @see #flushBuffer
	* @see #isCommitted
	*/
	void reset();

	/**
	* 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
	* {@link #setContentType}, {@link #setCharacterEncoding(String)} or {@link #setCharacterEncoding(Charset)},
	* <code>getWriter</code> hasn't been called yet, and the response hasn't been committed yet. If the deployment
	* descriptor contains a <code>locale-encoding-mapping-list</code> 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.
	* <p>
	* 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
	* {@link #setContentType} has been called with a charset specification, after {@link #setCharacterEncoding} has
	* been called, after <code>getWriter</code> has been called, or after the response has been committed.
	* <p>
	* 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
	* <code>Content-Language</code> header, the character encoding as part of the <code>Content-Type</code> 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.
	*
	* @param loc the locale of the response
	*
	* @see #getLocale
	* @see #setContentType
	* @see #setCharacterEncoding(String)
	* @see #setCharacterEncoding(Charset)
	*/
	void setLocale(Locale loc);

	/**
	* Returns the locale specified for this response using the {@link #setLocale} method. Calls made to
	* <code>setLocale</code> after the response is committed have no effect.
	*
	* @return The locale specified for this response using the {@link #setLocale} method. If no locale has been
	* specified, the container's default locale is returned.
	*
	* @see #setLocale
	*/
	Locale getLocale();

	}