    1   /*
    2    * $Header: /home/jerenkrantz/tmp/commons/commons-convert/cvs/home/cvs/jakarta-commons//httpclient/src/test/org/apache/commons/httpclient/server/HttpRequestHandlerChain.java,v 1.6 2004/11/28 15:44:39 olegk Exp $
    3    * $Revision: 480424 $
    4    * $Date: 2006-11-29 06:56:49 +0100 (Wed, 29 Nov 2006) $
    5    *
    6    * ====================================================================
    7    *
    8    *  Licensed to the Apache Software Foundation (ASF) under one or more
    9    *  contributor license agreements.  See the NOTICE file distributed with
    10   *  this work for additional information regarding copyright ownership.
    11   *  The ASF licenses this file to You under the Apache License, Version 2.0
    12   *  (the "License"); you may not use this file except in compliance with
    13   *  the License.  You may obtain a copy of the License at
    14   *
    15   *      http://www.apache.org/licenses/LICENSE-2.0
    16   *
    17   *  Unless required by applicable law or agreed to in writing, software
    18   *  distributed under the License is distributed on an "AS IS" BASIS,
    19   *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    20   *  See the License for the specific language governing permissions and
    21   *  limitations under the License.
    22   * ====================================================================
    23   *
    24   * This software consists of voluntary contributions made by many
    25   * individuals on behalf of the Apache Software Foundation.  For more
    26   * information on the Apache Software Foundation, please see
    27   * <http://www.apache.org/>.
    28   *
    29   * [Additional notices, if required by prior licensing conditions]
    30   *
    31   */
    32
    33  package org.apache.commons.httpclient.server;
    34
    35  import java.io.IOException;
    36  import java.util.ArrayList;
    37  import java.util.Iterator;
    38  import java.util.List;
    39
    40  /**
    41   * Maintains a chain of {@link HttpRequestHandler}s where new request-handlers
    42   * can be prepended/appended.
    43   *
    44   * For each call to {@link #processRequest(ResponseWriter,SimpleHttpServerConnection,RequestLine,Header[])}
    45   * we iterate over the chain from the start to the end, stopping as soon as a handler
    46   * has claimed the output.
    47   *
    48   * @author Christian Kohlschuetter
    49   */
    50  public class HttpRequestHandlerChain implements HttpRequestHandler {
    51
    52      private List subhandlers = new ArrayList();
    53
    54      public HttpRequestHandlerChain(final HttpRequestHandlerChain chain) {
    55          super();
    56          if (chain != null) {
    57              this.subhandlers.clear();
    58              this.subhandlers.addAll(chain.subhandlers);
    59          }
    60      }
    61
    62      public HttpRequestHandlerChain() {
    63          super();
    64      }
    65
    66      public synchronized void clear() {
    67          subhandlers.clear();
    68      }
    69
    70      public synchronized void prependHandler(HttpRequestHandler handler) {
    71          subhandlers.add(0,handler);
    72      }
    73
    74      public synchronized void appendHandler(HttpRequestHandler handler) {
    75          subhandlers.add(handler);
    76      }
    77
    78      public synchronized boolean processRequest(
    79          final SimpleHttpServerConnection conn,
    80          final SimpleRequest request) throws IOException
    81      {
    82          for(Iterator it=subhandlers.iterator();it.hasNext();) {
    83              HttpRequestHandler h = (HttpRequestHandler)it.next();
    84              boolean stop = h.processRequest(conn, request);
    85              if (stop) {
    86                  return true;
    87              }
    88          }
    89          return false;
    90      }
    91  }