大きな話のページ分け(一)

public class AbstractPageManager extends HibernateDaoSupport {

	/**
	 *   HQL  ，         HQL    ： 
	 * select ... from Organization o where o.parent is null 
	 *     ，    ： 
	 * select count(*) from Organization o where o.parent is null
	 * 
	 * @param hql
	 * @return
	 */
	private String getCountQuery(String hql) {
		//   from   
		int index = hql.indexOf("from");

		//   ：        ＳＱＬ  
		if (index != -1) {
			return "select count(*) " + hql.substring(index);
		}
		throw new SystemException("   HQL    ");
	}
	
	/**
	 *   HQL        
	 * 
	 * @param hql HQL  
	 * @param params HQL        
	 * @param offSet           
	 * @param pageSize        
	 * @return
	 */
	public PageModel searchPaginate(String hql, Object[] params, int offSet,
			int pageSize) {
		//     
		String strCount = getCountQuery(hql);

		//     
		Query query = getSession().createQuery(strCount);
		//  HQL            Query
		if (params != null && params.length > 0) {
			for (int i = 0; i < params.length; i++) {
				query.setParameter(i, params[i]);
			}
		}

		//       
		int intCount = ((Long) query.uniqueResult()).intValue();

		//   Organization  
		query = getSession().createQuery(hql);
		//  HQL            Query
		if (params != null && params.length > 0) {
			for (int i = 0; i < params.length; i++) {
				query.setParameter(i, params[i]);
			}
		}
		/*
		 * offSet             
		 * pageSize          
		 */
		query.setFirstResult(offSet);
		query.setMaxResults(pageSize);

		//  PageModel
		PageModel pageModel = new PageModel();
		pageModel.setDatas(query.list());
		pageModel.setTotal(intCount);
		
		return pageModel;
	}
}