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Posted to dev@commons.apache.org by rd...@apache.org on 2004/05/10 21:59:14 UTC

cvs commit: jakarta-commons/beanutils/optional/bean-collections/src/java/org/apache/commons/beanutils BeanPropertyValueChangeClosure.java

rdonkin     2004/05/10 12:59:14

  Added:       beanutils/optional/bean-collections/src/java/org/apache/commons/beanutils
                        BeanPropertyValueChangeClosure.java
  Log:
  Added new directory for bean collection components
  
  Revision  Changes    Path
  1.1                  jakarta-commons/beanutils/optional/bean-collections/src/java/org/apache/commons/beanutils/BeanPropertyValueChangeClosure.java
  
  Index: BeanPropertyValueChangeClosure.java
  ===================================================================
  /*
   * Copyright 2001-2004 The Apache Software Foundation.
   * 
   * Licensed under the Apache License, Version 2.0 (the "License");
   * you may not use this file except in compliance with the License.
   * You may obtain a copy of the License at
   * 
   *      http://www.apache.org/licenses/LICENSE-2.0
   * 
   * Unless required by applicable law or agreed to in writing, software
   * distributed under the License is distributed on an "AS IS" BASIS,
   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   * See the License for the specific language governing permissions and
   * limitations under the License.
   */ 
   
  package org.apache.commons.beanutils;
  
  import org.apache.commons.collections.Closure;
  import org.apache.commons.logging.Log;
  import org.apache.commons.logging.LogFactory;
  
  import java.lang.reflect.InvocationTargetException;
  
  
  /**
   * <p><code>Closure</code> that sets a property.</p>
   * <p>
   * An implementation of <code>org.apache.commons.collections.Closure</code> that updates
   * a specified property on the object provided with a specified value.
   * The <code>BeanPropertyValueChangeClosure</code> constructor takes two parameters which determine
   * what property will be updated and with what value.
   * <dl>
   *    <dt>
   *       <b><code><pre>public BeanPropertyValueChangeClosure( String propertyName, Object propertyValue )</pre></code></b>
   *    </dt>
   *    <dd>
   *       Will create a <code>Closure</code> that will update an object by setting the property
   *       specified by <code>propertyName</code> to the value specified by <code>propertyValue</code>.
   *    </dd>
   * </dl>
   *
   * <p/>
   * <strong>Note:</strong> Property names can be a simple, nested, indexed, or mapped property as defined by
   * <code>org.apache.commons.beanutils.PropertyUtils</code>.  If any object in the property path
   * specified by <code>propertyName</code> is <code>null</code> then the outcome is based on the
   * value of the <code>ignoreNull</code> attribute.
   *
   * <p/>
   * A typical usage might look like:
   * <code><pre>
   * // create the closure
   * BeanPropertyValueChangeClosure closure =
   *    new BeanPropertyValueChangeClosure( "activeEmployee", Boolean.TRUE );
   *
   * // update the Collection
   * CollectionUtils.forAllDo( peopleCollection, closure );
   * </pre></code>
   * <p/>
   *
   * This would take a <code>Collection</code> of person objects and update the
   * <code>activeEmployee</code> property of each object in the <code>Collection</code> to
   * <code>true</code>. Assuming...
   * <ul>
   *    <li>
   *       The top level object in the <code>peopleCollection</code> is an object which represents a
   *       person.
   *    </li>
   *    <li>
   *       The person object has a <code>setActiveEmployee( boolean )</code> method which updates
   *       the value for the object's <code>activeEmployee</code> property.
   *    </li>
   * </ul>
   *
   * @author Norm Deane
   * @see org.apache.commons.beanutils.PropertyUtils
   * @see org.apache.commons.collections.Closure
   */
  public class BeanPropertyValueChangeClosure implements Closure {
     
      /** For logging. */
      private final Log log = LogFactory.getLog(this.getClass());
  
      /**
       * The name of the property which will be updated when this <code>Closure</code> executes.
       */
      private String propertyName;
  
      /**
       * The value that the property specified by <code>propertyName</code>
       * will be updated to when this <code>Closure</code> executes.
       */
      private Object propertyValue;
  
      /**
       * Determines whether <code>null</code> objects in the property path will genenerate an
       * <code>IllegalArgumentException</code> or not. If set to <code>true</code> then if any objects
       * in the property path leading up to the target property evaluate to <code>null</code> then the
       * <code>IllegalArgumentException</code> throw by <code>PropertyUtils</code> will be logged but
       * not rethrown.  If set to <code>false</code> then if any objects in the property path leading
       * up to the target property evaluate to <code>null</code> then the
       * <code>IllegalArgumentException</code> throw by <code>PropertyUtils</code> will be logged and
       * rethrown.
       */
      private boolean ignoreNull;
  
      /**
       * Constructor which takes the name of the property to be changed, the new value to set
       * the property to, and assumes <code>ignoreNull</code> to be <code>false</code>.
       *
       * @param propertyName The name of the property that will be updated with the value specified by
       * <code>propertyValue</code>.
       * @param propertyValue The value that <code>propertyName</code> will be set to on the target
       * object.
       * @throws IllegalArgumentException If the propertyName provided is null or empty.
       */
      public BeanPropertyValueChangeClosure(String propertyName, Object propertyValue) {
          this(propertyName, propertyValue, false);
      }
  
      /**
       * Constructor which takes the name of the property to be changed, the new value to set
       * the property to and a boolean which determines whether <code>null</code> objects in the
       * property path will genenerate an <code>IllegalArgumentException</code> or not.
       *
       * @param propertyName The name of the property that will be updated with the value specified by
       * <code>propertyValue</code>.
       * @param propertyValue The value that <code>propertyName</code> will be set to on the target
       * object.
       * @param ignoreNull Determines whether <code>null</code> objects in the property path will
       * genenerate an <code>IllegalArgumentException</code> or not.
       * @throws IllegalArgumentException If the propertyName provided is null or empty.
       */
      public BeanPropertyValueChangeClosure(String propertyName, Object propertyValue, boolean ignoreNull) {
          super();
  
          if ((propertyName != null) && (propertyName.length() > 0)) {
              this.propertyName = propertyName;
              this.propertyValue = propertyValue;
              this.ignoreNull = ignoreNull;
          } else {
              throw new IllegalArgumentException("propertyName cannot be null or empty");
          }
      }
  
      /**
       * Updates the target object provided using the property update criteria provided when this
       * <code>BeanPropertyValueChangeClosure</code> was constructed.  If any object in the property
       * path leading up to the target property is <code>null</code> then the outcome will be based on
       * the value of the <code>ignoreNull</code> attribute. By default, <code>ignoreNull</code> is
       * <code>false</code> and would result in an <code>IllegalArgumentException</code> if an object
       * in the property path leading up to the target property is <code>null</code>.
       *
       * @param object The object to be updated.
       * @throws IllegalArgumentException If an IllegalAccessException, InvocationTargetException, or
       * NoSuchMethodException is thrown when trying to access the property specified on the object
       * provided. Or if an object in the property path provided is <code>null</code> and
       * <code>ignoreNull</code> is set to <code>false</code>.
       */
      public void execute(Object object) {
         
          try {
              PropertyUtils.setProperty(object, propertyName, propertyValue);
          } catch (IllegalArgumentException e) {
              final String errorMsg = "Unable to execute Closure. Null value encountered in property path...";
  
              if (ignoreNull) {
                  log.warn("WARNING: " + errorMsg, e);
              } else {
                  log.error("ERROR: " + errorMsg, e);
                  throw e;
              }
          } catch (IllegalAccessException e) {
              final String errorMsg = "Unable to access the property provided.";
              log.error(errorMsg, e);
              throw new IllegalArgumentException(errorMsg);
          } catch (InvocationTargetException e) {
              final String errorMsg = "Exception occurred in property's getter";
              log.error(errorMsg, e);
              throw new IllegalArgumentException(errorMsg);
          } catch (NoSuchMethodException e) {
              final String errorMsg = "Property not found";
              log.error(errorMsg, e);
              throw new IllegalArgumentException(errorMsg);
          }
      }
  
      /**
       * Returns the name of the property which will be updated when this <code>Closure</code> executes.
       *
       * @return The name of the property which will be updated when this <code>Closure</code> executes.
       */
      public String getPropertyName() {
          return propertyName;
      }
  
      /**
       * Returns the value that the property specified by <code>propertyName</code>
       * will be updated to when this <code>Closure</code> executes.
       *
       * @return The value that the property specified by <code>propertyName</code>
       * will be updated to when this <code>Closure</code> executes.
       */
      public Object getPropertyValue() {
          return propertyValue;
      }
  
      /**
       * Returns the flag that determines whether <code>null</code> objects in the property path will
       * genenerate an <code>IllegalArgumentException</code> or not. If set to <code>true</code> then
       * if any objects in the property path leading up to the target property evaluate to
       * <code>null</code> then the <code>IllegalArgumentException</code> throw by
       * <code>PropertyUtils</code> will be logged but not rethrown.  If set to <code>false</code> then
       * if any objects in the property path leading up to the target property evaluate to
       * <code>null</code> then the <code>IllegalArgumentException</code> throw by
       * <code>PropertyUtils</code> will be logged and rethrown.
       *
       * @return The flag that determines whether <code>null</code> objects in the property path will
       * genenerate an <code>IllegalArgumentException</code> or not.
       */
      public boolean isIgnoreNull() {
          return ignoreNull;
      }
  }
  
  
  

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