这个weblogging 设计得比较精巧

				package org.roller.util;
				
				/**
				 * This class contains helper methods
				 * for Roller pojos (only?)
				**/
				public abstract class PojoUtil
				{
				    public static boolean equals(boolean lEquals, Object a, Object b)
				    {
				        if (a == null)
				        {
				            lEquals = lEquals && (b == null);
				        }
				        else
				        {
				            lEquals = lEquals && a.equals(b);
				        }
				        return lEquals;
				    }
				
				    public static int addHashCode(int result, Object a)
				    {
						return (37 * result) + ((a != null) ? a.hashCode() : 0);
					}
				}