View Javadoc

1   /*
2    * Licensed to the Apache Software Foundation (ASF) under one or more
3    * contributor license agreements.  See the NOTICE file distributed with
4    * this work for additional information regarding copyright ownership.
5    * The ASF licenses this file to You under the Apache License, Version 2.0
6    * (the "License"); you may not use this file except in compliance with
7    * the License.  You may obtain a copy of the License at
8    *
9    *      http://www.apache.org/licenses/LICENSE-2.0
10   *
11   * Unless required by applicable law or agreed to in writing, software
12   * distributed under the License is distributed on an "AS IS" BASIS,
13   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14   * See the License for the specific language governing permissions and
15   * limitations under the License.
16   */
17  
18  package org.apache.commons.beanutils;
19  
20  import org.apache.commons.collections.Predicate;
21  import org.apache.commons.logging.Log;
22  import org.apache.commons.logging.LogFactory;
23  
24  import java.lang.reflect.InvocationTargetException;
25  
26  /***
27   * <p>Predicate implementation that applies the given <code>Predicate</code>
28   * to the result of calling the given property getter.
29   * </p>
30   */
31  public class BeanPredicate implements Predicate {
32     
33      private final Log log = LogFactory.getLog(this.getClass());
34      
35      /*** Name of the property whose value will be predicated */
36      private String propertyName;
37      /*** <code>Predicate</code> to be applied to the property value */
38      private Predicate predicate;
39  
40      /***
41       * Constructs a <code>BeanPredicate</code> that applies the given
42       * <code>Predicate</code> to the named property value.
43       * @param propertyName the name of the property whose value is to be predicated,
44       * not null
45       * @param predicate the <code>Predicate</code> to be applied,
46       * not null
47       */
48      public BeanPredicate(String propertyName, Predicate predicate) {
49          this.propertyName = propertyName;
50          this.predicate = predicate;
51      }
52  
53      /***
54       * Evaluates the given object by applying the {@link #getPredicate()}
55       * to a property value named by {@link #getPropertyName()}.
56       *
57       * @param object The object being evaluated
58       * @return the result of the predicate evaluation
59       * @throws IllegalArgumentException when the property cannot be evaluated
60       */
61      public boolean evaluate(Object object) {
62         
63          boolean evaluation = false;
64  
65          try {
66              Object propValue = PropertyUtils.getProperty( object, propertyName );
67              evaluation = predicate.evaluate(propValue);
68          } catch (IllegalArgumentException e) {
69              final String errorMsg = "Problem during evaluation.";
70              log.error("ERROR: " + errorMsg, e);
71              throw e;
72          } catch (IllegalAccessException e) {
73              final String errorMsg = "Unable to access the property provided.";
74              log.error(errorMsg, e);
75              throw new IllegalArgumentException(errorMsg);
76          } catch (InvocationTargetException e) {
77              final String errorMsg = "Exception occurred in property's getter";
78              log.error(errorMsg, e);
79              throw new IllegalArgumentException(errorMsg);
80          } catch (NoSuchMethodException e) {
81              final String errorMsg = "Property not found.";
82              log.error(errorMsg, e);
83              throw new IllegalArgumentException(errorMsg);
84          }
85  
86          return evaluation;
87      }
88  
89      /***
90       * Gets the name of the property whose value is to be predicated.
91       * in the evaluation.
92       * @return the property name, not null
93       */ 
94      public String getPropertyName() {
95          return propertyName;
96      }
97  
98      /*** 
99       * Sets the name of the property whose value is to be predicated.
100      * @param propertyName the name of the property whose value is to be predicated,
101      * not null
102      */
103     public void setPropertyName(String propertyName) {
104         this.propertyName = propertyName;
105     }
106 
107     /***
108      * Gets the <code>Predicate</code> to be applied to the value of the named property
109      * during {@link #evaluate}.
110      * @return <code>Predicate</code>, not null
111      */
112     public Predicate getPredicate() {
113         return predicate;
114     }
115 
116     /*** 
117      * Sets the <code>Predicate</code> to be applied to the value of the named property
118      * during {@link #evaluate(Object)}.
119      * @param predicate <code>Predicate</code>, not null
120      */
121     public void setPredicate(Predicate predicate) {
122         this.predicate = predicate;
123     }
124 
125 }