一个通用分页查询方法

/** 
 * HQL分页查询,可以指定具体的模式, 
 * 采用getCount方式,须在此层完成hsql的转换与查询。 
 * 注意参数Object...args的应用,可以在查询的设置查询条件用的(JDK5.0语法) 
 */  
public Page pagedQuery(String hql, int pageNo, int pageSize, Object... args) {  
    Assert.hasText(hql);  
    Query query = getSession().createQuery(hql);  
    for (int i = 0; i < args.length; i++) {  
        query.setParameter(i, args[i]);  
    }  
        String countQueryString = " select count (*) " + removeSelect(removeOrders(hql));  
        List countlist = getHibernateTemplate().find(countQueryString, args);  
        int totalCount = (Integer) countlist.get(0);  
        return HqlPage.getPageInstanceByCount(query, pageNo, pageSize, totalCount);  
}  
  
/** 
 * 去除select 子句,未考虑union的情况 
 */  
private static String removeSelect(String hql) {  
    Assert.hasText(hql);  
    int beginPos = hql.toLowerCase().indexOf("from");  
    Assert.isTrue(beginPos != -1, " hql : " + hql + " must has a keyword 'from'");  
    return hql.substring(beginPos);  
}  
  
/** 
 * 去除orderby 子句 
 */  
private static String removeOrders(String hql) {  
    Assert.hasText(hql);  
    Pattern p = Pattern.compile("order\\s*by[\\w|\\W|\\s|\\S]*", Pattern.CASE_INSENSITIVE);  
    Matcher m = p.matcher(hql);  
    StringBuffer sb = new StringBuffer();  
    while (m.find()) {  
        m.appendReplacement(sb, "");  
    }  
    m.appendTail(sb);  
    return sb.toString();  
}  

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