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1   /**
2    * Copyright 2005-2013 The Kuali Foundation
3    *
4    * Licensed under the Educational Community 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.opensource.org/licenses/ecl2.php
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.kuali.rice.krms.framework.engine.expression;
17  
18  import org.kuali.rice.krms.api.KrmsApiServiceLocator;
19  import org.kuali.rice.krms.api.engine.expression.ComparisonOperatorService;
20  
21  /**
22   * Contains utility methods for working with the ComparisonOperatorService
23   */
24  public final class ComparisonOperatorServiceUtils {
25  
26      // don't allow instances
27      private ComparisonOperatorServiceUtils() {
28          throw new UnsupportedOperationException();
29      }
30  
31      /**
32       * <P>checks if the value needs to be coerced from a String to another type, and if so it looks for an
33       * applicable StringCoercionExtension.</p>
34       *
35       * @param value the value of the argument that may or may not need coercion
36       * @param expectedType the name of the type that the function is expecting for the argument
37       * @param comparisonOperatorService the ComparisonOperatorService instance to use (if needed) for finding a StringCoercionExtension
38       * @return the coerced value, or the unchanged value if (1) no coercion needs to be done or (2) an applicable
39       * StringCoercionExtension can't be found.
40       */
41      public static Object coerceIfNeeded(Object value, String expectedType, ComparisonOperatorService comparisonOperatorService) {
42  
43          Object result = value;
44  
45          if (value instanceof String && !"java.lang.String".equals(expectedType)) {
46              String valueString = value.toString();
47              StringCoercionExtension coercionExtension =
48                      comparisonOperatorService.findStringCoercionExtension(expectedType, valueString);
49              if (coercionExtension != null) {
50                  result = coercionExtension.coerce(expectedType, valueString);
51              }
52          }
53  
54          return result;
55      }
56  }