/**
 * SELECT MAX(user.userId) from user_ user;
 */
DynamicQuery userQuery = DynamicQueryFactoryUtil.forClass(User.class, "user",PortalClassLoaderUtil.getClassLoader());
Projection projection =PropertyFactoryUtil.forName("user.userId").max();
userQuery.setProjection(projection);
try {
	List<Object>list = UserLocalServiceUtil.dynamicQuery(userQuery);
	System.out.println("MAX user id=>"+list.get(0));
	
} catch (SystemException e2) {
	e2.printStackTrace();
}