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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 org.apache.commons.logging.Log;
    20  /***
    21   *  Handles discovery and valuation of a
    22   *  boolean object property, of the
    23   *  form public boolean is<property> when executed.
    24   *
    25   *  We do this separately as to preserve the current
    26   *  quasi-broken semantics of get<as is property>
    27   *  get< flip 1st char> get("property") and now followed
    28   *  by is<Property>
    29   *
    30   *  @author <a href="geirm@apache.org">Geir Magnusson Jr.</a>
    31   *  @version $Id: BooleanPropertyExecutor.java,v 1.4 2004/02/28 13:45:21 yoavs Exp $
    32   */
    33  public class BooleanPropertyExecutor extends PropertyExecutor
    34  {
    35      public BooleanPropertyExecutor(Log rlog, org.apache.commons.jexl.util.introspection.Introspector is, Class clazz, String property)
    36      {
    37          super(rlog, is, clazz, property);
    38      }
    39
    40      protected void discover(Class clazz, String property)
    41      {
    42          try
    43          {
    44              char c;
    45              StringBuffer sb;
    46
    47              Object[] params = {  };
    48
    49              /*
    50               *  now look for a boolean isFoo
    51               */
    52
    53              sb = new StringBuffer("is");
    54              sb.append(property);
    55
    56              c = sb.charAt(2);
    57
    58              if (Character.isLowerCase(c))
    59              {
    60                  sb.setCharAt(2, Character.toUpperCase(c));
    61              }
    62
    63              methodUsed = sb.toString();
    64              method = introspector.getMethod(clazz, methodUsed, params);
    65
    66              if (method != null)
    67              {
    68                  /*
    69                   *  now, this has to return a boolean
    70                   */
    71
    72                  if (method.getReturnType() == Boolean.TYPE)
    73                      return;
    74
    75                  method = null;
    76              }
    77          }
    78          catch(Exception e)
    79          {
    80              rlog.error("PROGRAMMER ERROR : BooleanPropertyExector() : " + e);
    81          }
    82      }
    83  }