hibernate分页工具类

向右看齐 2022-08-27 04:56 219阅读 0赞

hibernate分页工具类，附带具体的分页方法

调用效果：

//查询说说  
    PageBean page= null;  
    page = new QueryHelper(Talk.class, "t")  
            .addCondition("t.user.id=?",visitUser.getId())  
            .addCondition("t.status=?", Talk.INT_VALUE_0)  
            .addCondition(isUser == VISITUSER_ROLE_2, "t.visibleRange in (?,?)",Talk.INT_VALUE_2,Talk.INT_VALUE_3)  
            .addCondition(isUser == VISITUSER_ROLE_3, "t.visibleRange in (?)",Talk.INT_VALUE_3)  
            .addCondition(timestamp!=0,"t.posttime<?",timestamp)  
            .addOrderProperty("t.posttime",false)  
            .preparePageBean(talkService, pageNum, pageSize);

1，分页工具类（QueryHelper.java）

package com.hl.zoneSystem_v01.utils;  
      
    import java.util.ArrayList;  
    import java.util.List;  
      
    import com.hl.zoneSystem_v01.domain.PageBean;  
    import com.hl.zoneSystem_v01.service.BaseService;  
      
    /** 
     * 用于辅助拼接HQL语句 
     *  
     * @author hl 
     *  
     */  
    public class QueryHelper {  
      
          
        //private String fromClause; // FROM子句  
        //private String whereClause  = ""; // Where子句  
        //private String orderByClause  = ""; // OrderBy子句  
        private StringBuffer fromClause = new StringBuffer(); // FROM子句  
        private StringBuffer whereClause  = new StringBuffer(); // Where子句  
        private StringBuffer orderByClause  = new StringBuffer(); // OrderBy子句  
          
          
      
        private List<Object> parameters = new ArrayList<Object>(); // 参数列表  
      
        /** 
         * 生成From子句 
         * @param <T> 
         *  
         * @param clazz 
         * @param alias 
         *            别名 
         */  
        public <T> QueryHelper(Class<T>clazz, String alias) {  
            //fromClause = "FROM " + clazz.getSimpleName() + " " + alias;  
            fromClause.append("FROM ").append(clazz.getSimpleName()).append(" ").append(alias);  
              
        }  
      
        /** 
         * 拼接Where子句 
         *  
         * @param condition 
         * @param params 
         */  
        public QueryHelper addCondition(String condition, Object... params) {  
            // 拼接  
            if (whereClause.length() == 0) {  
                //whereClause = " WHERE " + condition;  
                whereClause.append(" WHERE ").append(condition);  
            } else {  
                //whereClause += " AND " + condition;  
                whereClause.append(" AND ").append(condition);  
            }  
      
            // 参数  
            if (params != null) {  
                for (Object p : params) {  
                    parameters.add(p);  
                }  
            }  
      
            return this;  
        }  
      
        /** 
         * 如果第一个参数为true，则拼接Where子句 
         *  
         * @param append 
         * @param condition 
         * @param params 
         */  
        public QueryHelper addCondition(boolean append, String condition, Object... params) {  
            if (append) {  
                addCondition(condition, params);  
            }  
            return this;  
        }  
          
          
        /** 
         * 拼接where子句   已or的形式 
         */  
        public QueryHelper addOrCondition(String condition, Object... params) {  
            // 拼接  
            if (whereClause.length() == 0) {  
                //whereClause = " WHERE " + condition;  
                whereClause.append(" WHERE ").append(condition);  
            } else {  
                //whereClause += " OR " + condition;  
                whereClause.append(" OR ").append(condition);  
            }  
      
            // 参数  
            if (params != null) {  
                for (Object p : params) {  
                    parameters.add(p);  
                }  
            }  
      
            return this;  
        }  
      
        /** 
         * 如果第一个参数为true，则拼接Where子句   or形式  
         *  
         * @param append 
         * @param condition 
         * @param params 
         */  
        public QueryHelper addOrCondition(boolean append, String condition, Object... params) {  
            if (append) {  
                addOrCondition(condition, params);  
            }  
            return this;  
        }  
          
          
          
          
          
      
        /** 
         * 拼接OrderBy子句 
         *  
         * @param propertyName 
         *            参与排序的属性名 
         * @param asc 
         *            true表示升序，false表示降序 
         */  
        public QueryHelper addOrderProperty(String propertyName, boolean asc) {  
            if (orderByClause.length() == 0) {  
                //orderByClause = " ORDER BY " + propertyName + (asc ? " ASC" : " DESC");  
                orderByClause.append(" ORDER BY ").append(propertyName).append((asc ? " ASC" : " DESC"));  
            } else {  
                //orderByClause += ", " + propertyName + (asc ? " ASC" : " DESC");  
                orderByClause.append(", ").append(propertyName).append((asc ? " ASC" : " DESC"));  
            }  
            return this;  
        }  
      
        /** 
         * 如果第一个参数为true，则拼接OrderBy子句 
         *  
         * @param append 
         * @param propertyName 
         * @param asc 
         */  
        public QueryHelper addOrderProperty(boolean append, String propertyName, boolean asc) {  
            if (append) {  
                addOrderProperty(propertyName, asc);  
            }  
            return this;  
        }  
      
        /** 
         * 获取生成的用于查询数据列表的HQL语句 
         *  
         * @return 
         */  
        public String getListQueryHql() {  
            return fromClause.toString() + whereClause.toString() + orderByClause.toString();  
        }  
      
        /** 
         * 获取生成的用于查询总记录数的HQL语句 
         *  
         * @return 
         */  
        public String getCountQueryHql() {  
            StringBuffer sCount = new StringBuffer();  
            sCount.append("SELECT COUNT(*) ").append(fromClause.toString()).append(whereClause.toString());  
            //return "SELECT COUNT(*) " + fromClause + whereClause;  
            return sCount.toString();  
        }  
      
        /** 
         * 获取HQL中的参数值列表 
         *  
         * @return 
         */  
        public List<Object> getParameters() {  
            return parameters;  
        }  
      
        /** 
         * 查询分页信息，并放到值栈栈顶 
         *  
         * @param service 
         * @param pageNum 
         * @param pageSize 
         */  
        public PageBean preparePageBean(BaseService<?> service, int pageNum, int pageSize) {  
            PageBean pageBean = service.getPageBean(pageNum, pageSize, this);  
            //ActionContext.getContext().getValueStack().push(pageBean);  
            return pageBean;  
        }  
          
        /** 
         * 根据hql信息,查询列表信息 
         *  
         * @param service 
         * @param pageNum 
         * @param pageSize 
         */  
        public List prepareList(BaseService<?> service, int pageNum, int pageSize) {  
            List list = service.getEntity(pageNum, pageSize, this);  
            return list;  
        }  
    
        /** 
         * 根据hql信息的复合条件,查询单个的对象 
         *  
         *  
         */  
        public <T>T prepareObject(BaseService<T> service) {  
            return service.getEntity(this.getListQueryHql(), this.getParameters());  
        }

2，分页依赖的类、方法（PageBean.java  + BaseService.java）  
BaseService.java中方法getPageBean()

\----------------------------------------  
注：这里的getSession()方法为获取当前可用session  ------>   sessionFactory.getCurrentSession();

/** 
     * @ClassName: BaseServiceImpl 
     * @Description: 抽象的service实现,专门用于继承  
     * @project: zoneSystem_v01
     * @package: com.hl.zoneSystem_v01.service.impl
     * @author: hl
     * @version: V1.0
     * @since: JDK 1.6.0_21
     * @date: 2014-3-31 下午7:59:59 
     * @param <T> 
     */ 
    public abstract class BaseServiceImpl<T> implements BaseService<T> {
        
        /** (not Javadoc) 
         * @Title: getPageBean 
         * @Description: 公共的查询分页信息的方法 
         * @param pageNum 
         * @param pageSize 
         * @param queryHelper 
         * @return 
         * @see com.hl.zoneSystem_v01.dao.BaseDao#getPageBean(int, int, com.hl.zoneSystem_v01.utils.QueryHelper) 
         */   
        @Override  
        public PageBean getPageBean(int pageNum, int pageSize,QueryHelper queryHelper) {  
            //logger.debug("BaseDaoImpl.getPageBean( int pageNum, int pageSize, QueryHelper queryHelper )");  
            // 参数列表  
            List<Object> parameters = queryHelper.getParameters();  
      
            //logger.debug("queryHelper.getListQueryHql()----->"+queryHelper.getListQueryHql());  
            // 查询本页的数据列表    这里的getSession（）为获取当前可用的session------>sessionFactory.getCurrentSession();  
            Query listQuery = getSession().createQuery(queryHelper.getListQueryHql()); // 创建查询对象  
            if (parameters != null) { // 设置参数  
                for (int i = 0; i < parameters.size(); i++) {  
                    listQuery.setParameter(i, parameters.get(i));  
                }  
            }  
            listQuery.setFirstResult((pageNum - 1) * pageSize);  
            listQuery.setMaxResults(pageSize);  
            List list = listQuery.list(); // 执行查询  
      
            // 查询总记录数量  
            Query countQuery = getSession().createQuery(queryHelper.getCountQueryHql());  
            if (parameters != null) { // 设置参数  
                for (int i = 0; i < parameters.size(); i++) {  
                    countQuery.setParameter(i, parameters.get(i));  
                }  
            }  
            Long count = (Long) countQuery.uniqueResult(); // 执行查询  
      
            return new PageBean(pageNum, pageSize, count.intValue(), list);  
        }
    
    }

PageBean.java  
\-------------------------

/** 
     * 分页功能中的一页的信息 
     *  
     * @author hl 
     *  
     */  
    public class PageBean {  
      
        // 指定的或是页面参数  
        private int currentPage; // 当前页  
        private int pageSize; // 每页显示多少条  
      
        // 查询数据库  
        private int recordCount; // 总记录数  
        private List recordList; // 本页的数据列表  
      
        // 计算  
        private int pageCount; // 总页数  
        private int beginPageIndex; // 页码列表的开始索引（包含）  
        private int endPageIndex; // 页码列表的结束索引（包含）  
      
        /** 
         * 只接受前4个必要的属性，会自动的计算出其他3个属生的值 
         *  
         * @param currentPage 
         * @param pageSize 
         * @param recordCount 
         * @param recordList 
         */  
        public PageBean(int currentPage, int pageSize, int recordCount, List recordList) {  
            this.currentPage = currentPage;  
            this.pageSize = pageSize;  
            this.recordCount = recordCount;  
            this.recordList = recordList;  
      
            // 计算总页码  
            pageCount = (recordCount + pageSize - 1) / pageSize;  
      
            // 计算 beginPageIndex 和 endPageIndex  
            // >> 总页数不多于10页，则全部显示  
            if (pageCount <= 10) {  
                beginPageIndex = 1;  
                endPageIndex = pageCount;  
            }  
            // >> 总页数多于10页，则显示当前页附近的共10个页码  
            else {  
                // 当前页附近的共10个页码（前4个 + 当前页 + 后5个）  
                beginPageIndex = currentPage - 4;  
                endPageIndex = currentPage + 5;  
                // 当前面的页码不足4个时，则显示前10个页码  
                if (beginPageIndex < 1) {  
                    beginPageIndex = 1;  
                    endPageIndex = 10;  
                }  
                // 当后面的页码不足5个时，则显示后10个页码  
                if (endPageIndex > pageCount) {  
                    endPageIndex = pageCount;  
                    beginPageIndex = pageCount - 10 + 1;  
                }  
            }  
        }  
      
        public List getRecordList() {  
            return recordList;  
        }  
      
        public void setRecordList(List recordList) {  
            this.recordList = recordList;  
        }  
      
        public int getCurrentPage() {  
            return currentPage;  
        }  
      
        public void setCurrentPage(int currentPage) {  
            this.currentPage = currentPage;  
        }  
      
        public int getPageCount() {  
            return pageCount;  
        }  
      
        public void setPageCount(int pageCount) {  
            this.pageCount = pageCount;  
        }  
      
        public int getPageSize() {  
            return pageSize;  
        }  
      
        public void setPageSize(int pageSize) {  
            this.pageSize = pageSize;  
        }  
      
        public int getRecordCount() {  
            return recordCount;  
        }  
      
        public void setRecordCount(int recordCount) {  
            this.recordCount = recordCount;  
        }  
      
        public int getBeginPageIndex() {  
            return beginPageIndex;  
        }  
      
        public void setBeginPageIndex(int beginPageIndex) {  
            this.beginPageIndex = beginPageIndex;  
        }  
      
        public int getEndPageIndex() {  
            return endPageIndex;  
        }  
      
        public void setEndPageIndex(int endPageIndex) {  
            this.endPageIndex = endPageIndex;  
        }  
      
    }