// HttpServletResponse - this interface represents an HTTP response//// API based on documentation from JavaSoft.//// Copyright (C) 1996,1998 by Jef Poskanzer <jef@acme.com>. All rights reserved.//// Redistribution and use in source and binary forms, with or without// modification, are permitted provided that the following conditions// are met:// 1. Redistributions of source code must retain the above copyright//    notice, this list of conditions and the following disclaimer.// 2. Redistributions in binary form must reproduce the above copyright//    notice, this list of conditions and the following disclaimer in the//    documentation and/or other materials provided with the distribution.//// THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND// ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE// IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE// ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE// FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL// DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS// OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)// HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT// LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY// OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF// SUCH DAMAGE.//// Visit the ACME Labs Java page for up-to-date versions of this and other// fine Java utilities: http://www.acme.com/java/package Acme.Serve.servlet.http;import java.io.*;import Acme.Serve.servlet.*;/// This interface represents an HTTP response.// <P>// This is taken from JavaSoft's Servlet API documentation.// <P>// <A HREF="/resources/classes/Acme/Serve/servlet/http/HttpServletResponse.java">Fetch the software.</A><BR>// <A HREF="/resources/classes/Acme.tar.gz">Fetch the entire Acme package.</A>// <P>// @see Acme.Serve.servlet.Servletpublic interface HttpServletResponse extends ServletResponse    {    /// Adds the specified cookie to the response.  It can be called    // multiple times to set more than one cookie.    public void addCookie( Cookie cookie );    /// Checks whether the response message header has a field with the    // specified name.    public boolean containsHeader( String name );    /// Sets the status code and message for this response.    // @param code the status code    // @param msg the status message    public void setStatus( int code, String msg );    /// Sets the status code and a default message for this response.    // @param code the status code    public void setStatus( int code );    /// Sets the value of a header field.    // @param name the header field name    // @param value the header field value    public void setHeader( String name, String value );    /// Sets the value of an integer header field.    // @param name the header field name    // @param value the header field integer value    public void setIntHeader( String name, int value );    /// Sets the value of a long header field.    // @param name the header field name    // @param value the header field long value    public void setLongHeader( String name, long value );    /// Sets the value of a date header field.    // @param name the header field name    // @param value the header field date value    public void setDateHeader( String name, long date );    /// Writes an error response using the specified status code and message.    // @param code the status code    // @param msg the status message    // @exception IOException if an I/O error has occurred    public void sendError( int code, String msg ) throws IOException;    /// Writes an error response using the specified status code and a default    // message.    // @param code the status code    // @exception IOException if an I/O error has occurred    public void sendError( int code ) throws IOException;    /// Sends a redirect message to the client using the specified redirect    // location URL.    // @param location the redirect location URL    // @exception IOException if an I/O error has occurred    public void sendRedirect( String location ) throws IOException;    // URL session-encoding stuff.  Not implemented, but the API is here    // for compatibility.    /// 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 should include 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>    // 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.    public String encodeUrl( String url );    /// Encodes the specified URL for use in the sendRedirect method or, if    // encoding is not needed, returns the URL unchanged. The    // implementation of this method should include the logic to determine    // whether the session ID needs to be encoded in the URL.  Because the    // rules for making this determination differ from those used to    // decide whether to encode a normal link, this method is seperate    // from the encodeUrl method.    // <P>    // All URLs sent to the HttpServletResponse.sendRedirect method should be    // run through this method.  Otherwise, URL rewriting cannot be used with    // browsers which do not support cookies.    public String encodeRedirectUrl( String url );    // Status codes.    public static final int SC_CONTINUE = 100;    public static final int SC_SWITCHING_PROTOCOLS = 101;    public static final int SC_OK = 200;    public static final int SC_CREATED = 201;    public static final int SC_ACCEPTED = 202;    public static final int SC_NON_AUTHORITATIVE_INFORMATION = 203;    public static final int SC_NO_CONTENT = 204;    public static final int SC_RESET_CONTENT = 205;    public static final int SC_PARTIAL_CONTENT = 206;    public static final int SC_MULTIPLE_CHOICES = 300;    public static final int SC_MOVED_PERMANENTLY = 301;    public static final int SC_MOVED_TEMPORARILY = 302;    public static final int SC_SEE_OTHER = 303;    public static final int SC_NOT_MODIFIED = 304;    public static final int SC_USE_PROXY = 305;    public static final int SC_BAD_REQUEST = 400;    public static final int SC_UNAUTHORIZED = 401;    public static final int SC_PAYMENT_REQUIRED = 402;    public static final int SC_FORBIDDEN = 403;    public static final int SC_NOT_FOUND = 404;    public static final int SC_METHOD_NOT_ALLOWED = 405;    public static final int SC_NOT_ACCEPTABLE = 406;    public static final int SC_PROXY_AUTHENTICATION_REQUIRED = 407;    public static final int SC_REQUEST_TIMEOUT = 408;    public static final int SC_CONFLICT = 409;    public static final int SC_GONE = 410;    public static final int SC_LENGTH_REQUIRED = 411;    public static final int SC_PRECONDITION_FAILED = 412;    public static final int SC_REQUEST_ENTITY_TOO_LARGE = 413;    public static final int SC_REQUEST_URI_TOO_LONG = 414;    public static final int SC_UNSUPPORTED_MEDIA_TYPE = 415;    public static final int SC_INTERNAL_SERVER_ERROR = 500;    public static final int SC_NOT_IMPLEMENTED = 501;    public static final int SC_BAD_GATEWAY = 502;    public static final int SC_SERVICE_UNAVAILABLE = 503;    public static final int SC_GATEWAY_TIMEOUT = 504;    public static final int SC_HTTP_VERSION_NOT_SUPPORTED = 505;    }