クラス属性に値を割り当てる

import java.lang.reflect.Field;
import java.lang.reflect.Method;

public class Test
{

	/**
	 * @param args
	 */
	public static void main(String[] args)
	{
		User user1 = new User();
		User user2 = new User();
		user2.setAge(222);
		user2.setNum(333);
		user2.setUserName("222Name");
		User user = (User) replaceValue(user1, user2);
		System.out.println(user.toString());
		
	}
	
    public static String generateSetName(String fieldName) {  
        if (null == fieldName || "".equals(fieldName)) {  
            return null;  
        }  
        return "set" + fieldName.substring(0, 1).toUpperCase()  
                + fieldName.substring(1);  
    } 
	
	private static Object replaceValue(Object newObject, Object oldObject)
	{
		try
		{
			Field[] incrementFields = newObject.getClass().getDeclaredFields();
			Field[] oldFields = oldObject.getClass().getDeclaredFields();
			for (int i = 0; i < incrementFields.length; i++)
			{
				Field incrementField = incrementFields[i];
				incrementField.setAccessible(true);
				for (int j = 0; j < oldFields.length; j++)
				{
					Field field = incrementFields[j];
					field.setAccessible(true);
					if (incrementField.getName().equals(field.getName()))
					{
						if(incrementField.get(newObject) != null)
						{
							Method fieldSetMet = newObject.getClass()  
							.getMethod(generateSetName(incrementField.getName()), incrementField.getType());  
								fieldSetMet.invoke(oldObject, incrementField.get(newObject));
						}
							
					}
				}
			}
		} catch (Exception ex)
		{
			ex.printStackTrace();
		}
		return oldObject;

	}
	
	

}