// ServletContext - an interface for defining a servlet's environment
//
// 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;

/// An interface for defining a servlet's environment.
// It can be used by the servlet to obtain information about the
// environment (i.e. web server) in which it is running.
// <P>
// This is taken from JavaSoft's Servlet API documentation.
// <P>
// <A HREF="/resources/classes/Acme/Serve/servlet/ServletContext.java">Fetch the software.</A><BR>
// <A HREF="/resources/classes/Acme.tar.gz">Fetch the entire Acme package.</A>
// <P>
// @see Acme.Serve.servlet.Servlet

import java.util.*;

public interface ServletContext
    {

    /// Gets a servlet by name.
    // @param name the servlet name
    // @return null if the servlet does not exist
    // @exception ServletException if the servlet could not be initialized
    public Servlet getServlet( String name ) throws ServletException;

    ///  Enumerates the servlets in this context (server). Only servlets that
    // are accesible will be returned.  This enumeration always includes the
    // servlet itself.
    public Enumeration getServlets();

    ///  Enumerates the names of the servlets in this context (server).
    // Only servlets that are accesible will be returned.  This enumeration
    // always includes the servlet itself.
    public Enumeration getServletNames();

    /// Write information to the servlet log.
    // @param message the message to log
    public void log( String message );

    /// Write a stack trace to the servlet log.
    // @param exception the exception to get the stack trace from
    // @param message the message to log
    public void log( Exception exception, String message );

    /// Applies alias rules to the specified virtual path and returns the
    // corresponding real path.  It returns null if the translation
    // cannot be performed.
    // @param path the path to be translated
    public String getRealPath( String path );

    /// Returns the MIME type of the specified file.
    // @param file file name whose MIME type is required
    public String getMimeType( String file );

    /// Returns the name and version of the web server under which the servlet
    // is running.
    // Same as the CGI variable SERVER_SOFTWARE.
    public String getServerInfo();

    /// Returns the value of the named attribute of the network service, or
    // null if the attribute does not exist.  This method allows access to
    // additional information about the service, not already provided by
    // the other methods in this interface. 
    public Object getAttribute( String name );

    }