/*
    * $Header: /home/cvs/jakarta-commons/httpclient/src/java/org/apache/commons/httpclient/methods/OptionsMethod.java,v 1.12.2.2 2004/02/22 18:21:15 olegk Exp $
    * $Revision: 1.12.2.2 $
    * $Date: 2004/02/22 18:21:15 $
    *
    * ====================================================================
    *
    *  Copyright 1999-2004 The Apache Software Foundation
    *
   *  Licensed 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.
   * ====================================================================
   *
   * This software consists of voluntary contributions made by many
   * individuals on behalf of the Apache Software Foundation.  For more
   * information on the Apache Software Foundation, please see
   * <http://www.apache.org/>.
   *
   * [Additional notices, if required by prior licensing conditions]
   *
   */
  
  package org.apache.commons.httpclient.methods;
  
  import org.apache.commons.httpclient.Header;
  import org.apache.commons.httpclient.HttpConnection;
  import org.apache.commons.httpclient.HttpMethodBase;
  import org.apache.commons.httpclient.HttpState;
  
  import org.apache.commons.logging.LogFactory;
  import org.apache.commons.logging.Log;
  import java.util.Enumeration;
  import java.util.StringTokenizer;
  import java.util.Vector;
  
  
  /***
   * Implements the HTTP OPTIONS method.
   * <p>
   * The HTTP OPTIONS method is defined in section 9.2 of 
   * <a href="http://www.ietf.org/rfc/rfc2616.txt">RFC2616</a>:
   * <blockquote>
   *  The OPTIONS method represents a request for information about the
   *  communication options available on the request/response chain
   *  identified by the Request-URI. This method allows the client to
   *  determine the options and/or requirements associated with a resource,
   *  or the capabilities of a server, without implying a resource action
   *  or initiating a resource retrieval.
   * </blockquote>
   * </p>
   *
   * @author <a href="mailto:remm@apache.org">Remy Maucherat</a>
   * @author <a href="mailto:mbowler@GargoyleSoftware.com">Mike Bowler</a>
   * @author <a href="mailto:jsdever@apache.org">Jeff Dever</a>
   *
   * @version $Revision: 1.12.2.2 $
   * @since 1.0
   */
  public class OptionsMethod
      extends HttpMethodBase {
  
  
      // --------------------------------------------------------- Class Variables
  
      /*** Log object for this class. */
      private static final Log LOG = LogFactory.getLog(OptionsMethod.class);
  
      // ----------------------------------------------------------- Constructors
  
  
      /***
       * Method constructor.
       *
       * @since 1.0
       */
      public OptionsMethod() {
      }
  
  
      /***
       * Constructor specifying a URI.
       *
       * @param uri either an absolute or relative URI
       *
       * @since 1.0
       */
      public OptionsMethod(String uri) {
          super(uri);
      }
  
 
     // ----------------------------------------------------- Instance Variables
 
 
     /***
      * Methods allowed.
      */
     private Vector methodsAllowed = new Vector();
 
 
     // --------------------------------------------------------- Public Methods
 
     /***
      * Get the name.
      * @return "OPTIONS"
      * @since 2.0
      */
     public String getName() {
         return "OPTIONS";
     }
 
 
     /***
      * Is the specified method allowed ?
      * 
      * @param method The method to check.
      * @return true if the specified method is allowed.
      * @since 1.0
      */
     public boolean isAllowed(String method) {
         checkUsed();
         return methodsAllowed.contains(method);
     }
 
 
     /***
      * Get a list of allowed methods.
      * @return An enumeration of all the allowed methods.
      *
      * @since 1.0
      */
     public Enumeration getAllowedMethods() {
         checkUsed();
         return methodsAllowed.elements();
     }
 
 
     // ----------------------------------------------------- HttpMethod Methods
 
     /***
      * <p>
      * This implementation will parse the <tt>Allow</tt> header to obtain 
      * the set of methods supported by the resource identified by the Request-URI.
      * </p>
      *
      * @param state the {@link HttpState state} information associated with this method
      * @param conn the {@link HttpConnection connection} used to execute
      *        this HTTP method
      *
      * @see #readResponse
      * @see #readResponseHeaders
      * @since 2.0
      */
     protected void processResponseHeaders(HttpState state, HttpConnection conn) {
         LOG.trace("enter OptionsMethod.processResponseHeaders(HttpState, HttpConnection)");
 
         Header allowHeader = getResponseHeader("allow");
         if (allowHeader != null) {
             String allowHeaderValue = allowHeader.getValue();
             StringTokenizer tokenizer =
                 new StringTokenizer(allowHeaderValue, ",");
             while (tokenizer.hasMoreElements()) {
                 String methodAllowed =
                     tokenizer.nextToken().trim().toUpperCase();
                 methodsAllowed.addElement(methodAllowed);
             }
         }
     }
 
     /***
      * Return true if the method needs a content-length header in the request.
      *
      * @return true if a content-length header will be expected by the server
      *
      * @since 1.0
      */
     public boolean needContentLength() {
         return false;
     }
 
 
 }