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    1   /*
    2    * Copyright 2002-2006 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
    17  package org.apache.commons.jexl;
    18
    19  import org.apache.commons.jexl.context.HashMapContext;
    20
    21  /***
    22   *  Helper to create a context.  In the current implementation of JEXL, there
    23   *  is one implementation of JexlContext - {@link HashMapContext}, and there
    24   *  is no reason not to directly instantiate {@link HashMapContext} in your
    25   *  own application.
    26   *
    27   *  @since 1.0
    28   *  @author <a href="mailto:geirm@apache.org">Geir Magnusson Jr.</a>
    29   *  @version $Id: JexlHelper.java 397092 2006-04-26 05:11:28Z dion $
    30   */
    31  public class JexlHelper {
    32      /*** singleton instance. */
    33      protected static JexlHelper helper = new JexlHelper();
    34
    35      /*** @return the single instance. */
    36      protected static JexlHelper getInstance() {
    37          return helper;
    38      }
    39
    40      /***
    41       * Returns a new {@link JexlContext}.
    42       * @return a new JexlContext
    43       */
    44      public static JexlContext createContext() {
    45          return getInstance().newContext();
    46      }
    47
    48      /***
    49       * Creates and returns a new {@link JexlContext}.
    50       * The current implementation creates a new instance of
    51       * {@link HashMapContext}.
    52       * @return a new JexlContext
    53       */
    54      protected JexlContext newContext() {
    55          return new HashMapContext();
    56      }
    57  }