    1   /*
    2    * Copyright 1999-2004 The Apache Software Foundation
    3    *
    4    * Licensed under the Apache License, Version 2.0 (the "License");
    5    * you may not use this file except in compliance with the License.
    6    * You may obtain a copy of the License at
    7    *
    8    *     http://www.apache.org/licenses/LICENSE-2.0
    9    *
    10   * Unless required by applicable law or agreed to in writing, software
    11   * distributed under the License is distributed on an "AS IS" BASIS,
    12   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    13   * See the License for the specific language governing permissions and
    14   * limitations under the License.
    15   */
    16  package org.apache.commons.jxpath.servlet;
    17
    18  import org.apache.commons.jxpath.Variables;
    19
    20  /***
    21   * Implementation of the Variables interface that provides access
    22   * to a single object using a reserved name (keyword).
    23   *
    24   * @author Dmitri Plotnikov
    25   * @version $Revision: 1.6 $ $Date: 2004/02/29 14:17:40 $
    26   */
    27  public class KeywordVariables implements Variables {
    28
    29      private String keyword;
    30      private Object object;
    31
    32      public KeywordVariables(String keyword, Object object) {
    33          this.keyword = keyword;
    34          this.object = object;
    35      }
    36
    37      public boolean isDeclaredVariable(String variable) {
    38          return variable.equals(keyword);
    39      }
    40
    41      public Object getVariable(String variable) {
    42          if (variable.equals(keyword)) {
    43              return object;
    44          }
    45          return null;
    46      }
    47
    48      public void declareVariable(String variable, Object value) {
    49          throw new UnsupportedOperationException(
    50              "Cannot declare new keyword variables.");
    51      }
    52
    53      public void undeclareVariable(String variable) {
    54          throw new UnsupportedOperationException(
    55              "Cannot declare new keyword variables.");
    56      }
    57  }