httpservletresponse.java

业界著名的tomcat服务器的最新6.0的源代码。

/*
* 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 javax.servlet.http;

import java.io.IOException;

import javax.servlet.ServletResponse;

/**
 *
 * Extends the {@link ServletResponse} interface to provide HTTP-specific
 * functionality in sending a response.  For example, it has methods
 * to access HTTP headers and cookies.
 *
 * <p>The servlet container creates an <code>HttpServletResponse</code> object
 * and passes it as an argument to the servlet's service methods
 * (<code>doGet</code>, <code>doPost</code>, etc).
 *
 * 
 * @author	Various
 * @version	$Version$
 *
 * @see		javax.servlet.ServletResponse
 *
 */



public interface HttpServletResponse extends ServletResponse {

    /**
     * Adds the specified cookie to the response.  This method can be called
     * multiple times to set more than one cookie.
     *
     * @param cookie the Cookie to return to the client
     *
     */

    public void addCookie(Cookie cookie);

    /**
     * Returns a boolean indicating whether the named response header 
     * has already been set.
     * 
     * @param	name	the header name
     * @return		<code>true</code> if the named response header 
     *			has already been set; 
     * 			<code>false</code> otherwise
     */

    public boolean containsHeader(String name);

    /**
     * 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.
     * 
     * <p>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.
     *
     * @param	url	the url to be encoded.
     * @return		the encoded URL if encoding is needed;
     * 			the unchanged URL otherwise.
     */

    public String encodeURL(String url);

    /**
     * Encodes the specified URL for use in the
     * <code>sendRedirect</code> 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 separated from the
     * <code>encodeURL</code> method.
     * 
     * <p>All URLs sent to the <code>HttpServletResponse.sendRedirect</code>
     * method should be run through this method.  Otherwise, URL
     * rewriting cannot be used with browsers which do not support
     * cookies.
     *
     * @param	url	the url to be encoded.
     * @return		the encoded URL if encoding is needed;
     * 			the unchanged URL otherwise.
     *
     * @see #sendRedirect
     * @see #encodeUrl
     */

    public String encodeRedirectURL(String url);

    /**
     * @deprecated	As of version 2.1, use encodeURL(String url) instead
     *
     * @param	url	the url to be encoded.
     * @return		the encoded URL if encoding is needed; 
     * 			the unchanged URL otherwise.
     */

    public String encodeUrl(String url);
    
    /**
     * @deprecated	As of version 2.1, use 
     *			encodeRedirectURL(String url) instead
     *
     * @param	url	the url to be encoded.
     * @return		the encoded URL if encoding is needed; 
     * 			the unchanged URL otherwise.
     */

    public String encodeRedirectUrl(String url);

    /**
     * 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. 
     *
     * <p>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.
     *
     * @param	sc	the error status code
     * @param	msg	the descriptive message
     * @exception	IOException	If an input or output exception occurs
     * @exception	IllegalStateException	If the response was committed
     */
   
    public void sendError(int sc, String msg) throws IOException;

    /**
     * Sends an error response to the client using the specified status
     * code and clearing the buffer. 
     * <p>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.
     *
     * @param	sc	the error status code
     * @exception	IOException	If an input or output exception occurs
     * @exception	IllegalStateException	If the response was committed
     *						before this method call
     */

    public void sendError(int sc) throws IOException;

    /**
     * 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.
     *
     * <p>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.
     *
     * @param		location	the redirect location URL
     * @exception	IOException	If an input or output exception occurs
     * @exception	IllegalStateException	If the response was committed or
 if a partial URL is given and cannot be converted into a valid URL
     */

    public void sendRedirect(String location) throws IOException;
    
    /**
     * 
     * 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
     * <code>containsHeader</code> method can be used to test for the
     * presence of a header before setting its value.
     * 
     * @param	name	the name of the header to set
     * @param	date	the assigned date value
     * 
     * @see #containsHeader
     * @see #addDateHeader
     */

    public void setDateHeader(String name, long date);
    
    /**
     * 
     * 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.
     * 
     * @param	name	the name of the header to set
     * @param	date	the additional date value
     * 
     * @see #setDateHeader
     */

    public void addDateHeader(String name, long date);
    
    /**
     *
     * 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 <code>containsHeader</code> method can be
     * used to test for the presence of a header before setting its
     * value.
     * 
     * @param	name	the name of the header
     * @param	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 #containsHeader
     * @see #addHeader
     */

    public void setHeader(String name, String value);
    
    /**
     * Adds a response header with the given name and value.
     * This method allows response headers to have multiple values.
     * 
     * @param	name	the name of the header
     * @param	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 #setHeader
     */

    public void addHeader(String name, String value);

    /**
     * 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 <code>containsHeader</code>
     * method can be used to test for the presence of a header before
     * setting its value.
     *
     * @param	name	the name of the header
     * @param	value	the assigned integer value
     *
     * @see #containsHeader
     * @see #addIntHeader
     */

    public void setIntHeader(String name, int value);

    /**
     * Adds a response header with the given name and
     * integer value.  This method allows response headers to have multiple
     * values.
     *
     * @param	name	the name of the header
     * @param	value	the assigned integer value
     *
     * @see #setIntHeader
     */

    public void addIntHeader(String name, int value);


    
    /**
     * 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 application, the <code>sendError</code> method should be used
     * instead.
     * <p> The container clears the buffer and sets the Location header, preserving
     * cookies and other headers.
     *
     * @param	sc	the status code
     *
     * @see #sendError
     */

    public void setStatus(int sc);
  
    /**
     * @deprecated As of version 2.1, due to ambiguous meaning of the 
     * message parameter. To set a status code 
     * use <code>setStatus(int)</code>, to send an error with a description
     * use <code>sendError(int, String)</code>.
     *
     * Sets the status code and message for this response.
     * 
     * @param	sc	the status code
     * @param	sm	the status message