package org.oxerr.commons.ws.rs.bean;
   
   import java.lang.reflect.InvocationTargetException;
   
   import org.apache.commons.beanutils.BeanUtils;
   import org.apache.commons.beanutils.BeanUtilsBean;
   import org.apache.commons.beanutils.ContextClassLoaderLocal;
   
   public class NullAwareBeanUtilsBean extends BeanUtilsBean {
  
  	/**
  	 * Contains <code>NullAwareBeanUtilsBean</code> instances indexed by context classloader.
  	 */
  	private static final ContextClassLoaderLocal<NullAwareBeanUtilsBean>
  		BEANS_BY_CLASSLOADER = new ContextClassLoaderLocal<NullAwareBeanUtilsBean>() {
  			// Creates the default instance used when the context classloader is unavailable
  			@Override
  			protected NullAwareBeanUtilsBean initialValue() {
  				return new NullAwareBeanUtilsBean();
  			}
  		};
  
  	/**
  	 * Gets the instance which provides the functionality for {@link BeanUtils}.
  	 * This is a pseudo-singleton - an single instance is provided per (thread) context classloader.
  	 * This mechanism provides isolation for web apps deployed in the same container.
  	 *
  	 * @return The (pseudo-singleton) BeanUtils bean instance
  	 */
  	public static NullAwareBeanUtilsBean getInstance() {
  		return BEANS_BY_CLASSLOADER.get();
  	}
  
  	@Override
  	public void copyProperty(Object dest, String name, Object value)
  			throws IllegalAccessException, InvocationTargetException {
  		if (value == null) {
  			return;
  		}
  
  		super.copyProperty(dest, name, value);
  	}
  
  }