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    1   /*
    2    * Copyright 2000-2001,2004 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
    17  package org.apache.commons.jexl.util;
    18
    19  import java.lang.reflect.InvocationTargetException;
    20
    21  import org.apache.commons.logging.Log;
    22
    23
    24  /***
    25   * Executor that simply tries to execute a get(key)
    26   * operation. This will try to find a get(key) method
    27   * for any type of object, not just objects that
    28   * implement the Map interface as was previously
    29   * the case.
    30   *
    31   * @since 1.0
    32   * @author <a href="mailto:jvanzyl@apache.org">Jason van Zyl</a>
    33   * @version $Id: GetExecutor.java 398171 2006-04-29 14:57:29Z dion $
    34   */
    35  public class GetExecutor extends AbstractExecutor {
    36      /***
    37       * Container to hold the 'key' part of
    38       * get(key).
    39       */
    40      private final Object[] args = new Object[1];
    41
    42      /***
    43       * Default constructor.
    44       *
    45       * @param r The instance log.
    46       * @param ispect The JEXL introspector.
    47       * @param c The class being examined.
    48       * @param key The key for the get(key) operation.
    49       * @throws Exception Failure while trying to obtain the pertinent method.
    50       */
    51      public GetExecutor(Log r,
    52              org.apache.commons.jexl.util.introspection.Introspector ispect,
    53              Class c, String key) throws Exception {
    54          rlog = r;
    55          args[0] = key;
    56          method = ispect.getMethod(c, "get", args);
    57      }
    58
    59      /***
    60       * {@inheritDoc}
    61       */
    62      public Object execute(Object o)
    63      throws IllegalAccessException, InvocationTargetException {
    64          if (method == null) {
    65              return null;
    66          }
    67
    68          return method.invoke(o, args);
    69      }
    70
    71  }
    72