001// ***************************************************************************************************************************
002// * Licensed to the Apache Software Foundation (ASF) under one or more contributor license agreements.  See the NOTICE file *
003// * distributed with this work for additional information regarding copyright ownership.  The ASF licenses this file        *
004// * to you under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance            *
005// * with the License.  You may obtain a copy of the License at                                                              *
006// *                                                                                                                         *
007// *  http://www.apache.org/licenses/LICENSE-2.0                                                                             *
008// *                                                                                                                         *
009// * Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an  *
010// * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.  See the License for the        *
011// * specific language governing permissions and limitations under the License.                                              *
012// ***************************************************************************************************************************
013package org.apache.juneau.rest.vars;
014
015import org.apache.juneau.rest.*;
016import org.apache.juneau.svl.*;
017
018/**
019 * Servlet init parameter variable resolver.
020 * 
021 * <p>
022 * The format for this var is <js>"$I{key[,defaultValue]}"</js>.
023 * 
024 * <p>
025 * This variable resolver requires that a {@link RestRequest} object be set as a context object on the resolver or a
026 * session object on the resolver session.
027 * 
028 * <p>
029 * Values are pulled from the {@link RestServlet#getInitParameter(String)} method.
030 * 
031 * <p>
032 * Since this is a {@link SimpleVar}, any variables contained in the result will be recursively resolved.
033 * Likewise, if the arguments contain any variables, those will be resolved before they are passed to this var.
034 * 
035 * <h5 class='section'>See Also:</h5>
036 * <ul>
037 *    <li class='link'><a class="doclink" href="../../../../../overview-summary.html#juneau-rest-server.SvlVariables">Overview &gt; juneau-rest-server &gt; SVL Variables</a>
038 * </ul>
039 */
040public class ServletInitParamVar extends DefaultingVar {
041
042   /** The name of this variable. */
043   public static final String NAME = "I";
044
045   /**
046    * Constructor.
047    */
048   public ServletInitParamVar() {
049      super(NAME);
050   }
051
052   @Override /* Parameter */
053   public String resolve(VarResolverSession session, String key) {
054      return session.getSessionObject(RestRequest.class, RequestVar.SESSION_req).getContext().getServletInitParameter(key);
055   }
056}