学步园

 

Page的实现 HibernatePage.java 和以前一样

package cn.loen.platform.util.page;

import java.util.List;

public class HibernatePageimplements Page {

    private List elements;

    private int pageSize;

    private int pageNumber;

    private int totalElements;

    /**
     * 构建HibernatePage对象，完成数据的分页处理
     *
     * @param elements
     *            List数据源
     * @param totalElements
     *            记录总数
     * @param pageNumber
     *            当前页编码，从1开始，如果传的值为Integer.MAX_VALUE表示获取最后一页。
     *            如果你不知道最后一页编码，传Integer.MAX_VALUE即可。如果当前页超过总页数，也表示最后一页。
     *            这两种情况将重新更改当前页的页码为最后一页编码。
     * @param pageSize
     *            每一页显示的条目数
     */
    public HibernatePage(List elements, int totalElements, int pageNumber,
                         int pageSize) {
        this.elements = elements;
        this.totalElements = totalElements;
        this.pageNumber = pageNumber;
        this.pageSize = pageSize;
        if (this.pageNumber == Integer.MAX_VALUE ||
            this.pageNumber > getLastPageNumber()) {
            this.pageNumber = getLastPageNumber();
        }
    }

    public boolean isFirstPage() {
        return getThisPageNumber() == 1;
    }

    public boolean isLastPage() {
        return getThisPageNumber() >= getLastPageNumber();
    }

    public boolean hasNextPage() {
        return getLastPageNumber() > getThisPageNumber();
    }

    public boolean hasPreviousPage() {
        return getThisPageNumber() > 1;
    }

    public int getLastPageNumber() {
        return totalElements % this.pageSize == 0 ? totalElements
                / this.pageSize : totalElements / this.pageSize + 1;
    }

    public List getThisPageElements() {
        return elements;
    }

    public int getTotalNumberOfElements() {
        return totalElements;
    }

    public int getThisPageFirstElementNumber() {
        return (getThisPageNumber() - 1) * getPageSize() + 1;
    }

    public int getThisPageLastElementNumber() {
        int fullPage = getThisPageFirstElementNumber() + getPageSize() - 1;
        return getTotalNumberOfElements() < fullPage ? getTotalNumberOfElements()
                : fullPage;
    }

    public int getNextPageNumber() {
        int nextPage = getThisPageNumber() + 1;
        return nextPage < getLastPageNumber() ? nextPage : getLastPageNumber();
    }

    public int getPreviousPageNumber() {
        int previousPage = getThisPageNumber() - 1;
        return 1 < previousPage ? previousPage : 1;
    }

    public int getPageSize() {
        return pageSize;
    }

    public int getThisPageNumber() {
        return pageNumber;
    }

    public void setThisPageElements(List ls) {
        elements = ls;
    }
}

 

关键 QueryHandler.java 查询处理用于Hibernate查询

SQL查询见 上篇文章

 

package cn.loen.platform.util.query;

import java.util.List;
import org.hibernate.HibernateException;
import org.hibernate.Session;
import org.hibernate.Query;
import cn.loen.platform.util.page.HibernatePage;
import cn.loen.platform.util.page.Page;
import cn.loen.platform.common.BaseDAO;
import java.util.Map;
import java.util.Set;
import java.util.Iterator;
/**
 *
 * <p>Title: www.loen.cn</p>
 *
 * <p>Description: v1.0</p>
 *
 * <p>Copyright: Copyright (c) 2006</p>
 *
 * <p>Company: loen</p>
 *
 * @author bright(9709583@gmail.com)
 * @version 1.0
 */
public class QueryHandler {

    private static QueryHandler instance = new QueryHandler();

    public static QueryHandler instance() {
        return instance;
    }

    private QueryHandler() {
    }

    /**
     * 得到记录总数
     * @param hql String
     * @param values Object[]
     * @return int
     * @throws HibernateException
     */
    public int getTotalCountS(String hql, Object[] values) throws
            HibernateException {
        Integer count = new Integer(0);
        /**
         * 去掉排序
         */
        int sql_orderby = hql.indexOf("order by");
        if(sql_orderby>0)
        hql = hql.substring(0,sql_orderby);
        /**
         * 去掉条件
         */
        hql=(hql.split("from"))[1];
        StringBuffer countStr = new StringBuffer("select count(*) from");
        countStr.append(hql);
        Session session = null;
        List list = null;
        try {
            session = BaseDAO.getSession();
            Query query = session.createQuery(countStr.toString());
            for (int i = 0; i < values.length; i++) {
                int z = i;
                 query.setParameter(z=z==0?0:i*2, values[i]);
                 query.setParameter(z=z==0?1:i*2+1, values[i]);

/*第二版 不用管查询参数是否为null 把所有的查询条件都写到String hql语句中

注意要把所有的查询条件的null转化为' '(空字符串);

例如:String hql = "select * from Table as t where (t.name=? or ' '=?) and (t.country=? or ' '=?)";

*/

            }
            list = query.list();

            if (!list.isEmpty())
                count = (Integer) list.get(0);
            return count.intValue();

        } finally {
            session.close();
        }
    }
    /**
     * @deprecated
     * @param hql String
     * @param values Object[]
     * @return int
     * @throws HibernateException
     */
    public int getTotalCount(String hql, Object[] values) throws
            HibernateException {
        Integer count = new Integer(0);
        /**
         * 去掉排序
         */
        int sql_orderby = hql.indexOf("order by");
        if(sql_orderby>0)
        hql = hql.substring(0,sql_orderby);
        /**
         * 去掉条件
         */
        hql=(hql.split("from"))[1];
        StringBuffer countStr = new StringBuffer("select count(*) from");
        countStr.append(hql);
        Session session = null;
        List list = null;
        try {
            session = BaseDAO.getSession();
            Query query = session.createQuery(countStr.toString());
            for (int i = 0; i < values.length; i++) {
                 query.setParameter(i, values[i]);//第一版 需要对hql的查询参数进行判断 是否存在 如果存在 就在String hql 后面加上" and Value=?"
            }
            list = query.list();

            if (!list.isEmpty())
                count = (Integer) list.get(0);
            return count.intValue();

        } finally {
            session.close();
        }
    }

    public int getTotalCountMap(String hql, Map map) throws
           HibernateException {
              Integer count = new Integer(0);
        /**
         * 去掉排序
         */
        if(StringUtils.contains(hql,"order by"))
            hql = StringUtils.substringBefore(hql,"order by");
        /**
         * 去掉fetch
         */
        if(StringUtils.contains(hql,"fetch"))
            hql = StringUtils.replace(hql,"fetch","");
        /**
         * 去掉条件
         */
        hql = StringUtils.substringAfter(hql,"from");
        StringBuffer countStr = new StringBuffer("select count(*) from");

       countStr.append(hql);
       Session session = null;
       List list = null;
       try {
           session = BaseDAO.getSession();
           Query query = session.createQuery(countStr.toString());
           Set set = map.keySet();
            Iterator it = set.iterator();
            while(it.hasNext())
            {
                String key = (String)it.next();
                Object value = map.get(key);
                query.setParameter(key,value);
            }

/*由于第二版有个参数的顺序问题 就是页面传递过来的list或者String[]的顺序必须和hql的查询条件顺序一致 故利用Hibernate的查询改写成map

例如:String hql = "select * from Table as t where (t.name=:name or ' '=:name) and (t.country=:country or ' '=:country)";

页面传递进来只需要传递一个Map map = new Hashmap();

map.put("country",value0);map.put("name",value1);

*/

 

 

 

 

           list = query.list();

           if (!list.isEmpty())
               count = (Integer) list.get(0);
           return count.intValue();

       } finally {
           session.close();
       }
   }

    /**
     * 按页数得到需要记录数
     * @param hql String
     * @param values Object[]
     * @param pageNo int
     * @param pageSize int
     * @return List
     * @throws HibernateException
     */
    public List queryS(String hql, Object[] values, int pageNo, int pageSize) throws
            HibernateException {
        List list = null;
        Session session = null;
        try {
            session = BaseDAO.getSession();
            Query query = session.createQuery(hql);
            for (int i = 0; i < values.length; i++) {
                int z = i;
                query.setParameter(z=z==0?0:i*2, values[i]);
                query.setParameter(z=z==0?1:i*2+1, values[i]);
            }
            query.setFirstResult((pageNo - 1) * pageSize);
            query.setMaxResults(pageSize);

            return query.list();
        } finally {
            session.close();
        }
    }
    /**
     * @deprecated
     * @param hql String
     * @param values Object[]
     * @param pageNo int
     * @param pageSize int
     * @return List
     * @throws HibernateException
     */
    public List query(String hql, Object[] values, int pageNo, int pageSize) throws
            HibernateException {
        List list = null;
        Session session = null;
        try {
            session = BaseDAO.getSession();
            Query query = session.createQuery(hql);
            for (int i = 0; i < values.length; i++) {
                int z = i;
                query.setParameter(i, values[i]);
            }
            query.setFirstResult((pageNo - 1) * pageSize);
            query.setMaxResults(pageSize);

            return query.list();
        } finally {
            session.close();
        }
    }

    public List queryMap(String hql, Map map, int pageNo, int pageSize) throws
           HibernateException {
       List list = null;
       Session session = null;
       try {
           session = BaseDAO.getSession();
           Query query = session.createQuery(hql);
           Set set = map.keySet();
           Iterator it = set.iterator();
           while(it.hasNext())
           {
               String key = (String)it.next();
               Object value = map.get(key);
               query.setParameter(key,value);
           }
           query.setFirstResult((pageNo - 1) * pageSize);
           query.setMaxResults(pageSize);

           return query.list();
       } finally {
           session.close();
       }
   }

    /**
     * 取得全部记录
     * @param hql String
     * @param values Object[]
     * @return List
     * @throws HibernateException
     */
    public List queryAll(String hql, Object[] values) throws HibernateException {
        List list = null;
        Session session = null;
        try {
            session = BaseDAO.getSession();
            Query query = session.createQuery(hql);
            for (int i = 0; i < values.length; i++) {
                query.setParameter(i, values[i]);
            }
            return query.list();
        } finally {
            session.close();
        }
    }

 public Page queryByPage(int pageNumber, int pageSize, Object[] values,
   String hql) {
  Page page = null;
  try {
   int total = QueryHandler.instance().getTotalCount(hql, values);
   List querylist = QueryHandler.instance().query(hql, values,
     pageNumber, pageSize);
   page = new HibernatePage(querylist, total, pageNumber, pageSize);
  } catch (Exception e) {
   e.printStackTrace();
  }
  return page;
 }
        public Page queryByPageS(int pageNumber, int pageSize, Object[] values,
                String hql) {
        Page page = null;
        try {
                int total = QueryHandler.instance().getTotalCountS(hql, values);
                List querylist = QueryHandler.instance().queryS(hql, values,
                                pageNumber, pageSize);
                page = new HibernatePage(querylist, total, pageNumber, pageSize);
        } catch (Exception e) {
                e.printStackTrace();
        }
        return page;
}

        public Page queryByPageMap(int pageNumber, int pageSize, Map map,
                        String hql) {
                Page page = null;
                try {
                        int total = QueryHandler.instance().getTotalCountMap(hql, map);
                        List querylist = QueryHandler.instance().queryMap(hql, map,
                                        pageNumber, pageSize);
                        page = new HibernatePage(querylist, total, pageNumber, pageSize);
                } catch (Exception e) {
                        e.printStackTrace();
                }
                return page;
        }
}

 

Services 调用 XXServices.java

 

public XXServices{
    public Page queryCourseByPage(int pageNum, int pageSize, Map map) throws BusinessException {
      String hql = "from Course as c where ((:provincecode='') or (c.provincecode=:provincecode)) and ((:citycode='') or (c.citycode=:citycode)) and ((:recommendernum='') or (c.recommendernum=:recommendernum)) and ((:isdisable='') or (c.isdisable=:isdisable)) and ((:coursename = '') or (c.coursename like '%' || :coursename || '%'))";
      map.put("isdisable","Y");
      Page page = null;
      try {
          page = QueryHandler.instance().queryByPageMap(pageNum, pageSize,
                  map,
                  hql);
      } catch (Exception e) {
          e.printStackTrace();
          throw new BusinessException(e.getMessage());
      }
      return page;
  }

}

 

 

 

 

Servlet调用: CourseAction.java

 

public class CourseAction extends DispatchAction {

     public ActionForward list(ActionMapping mapping, ActionForm form,
                              HttpServletRequest request,
                              HttpServletResponse response) throws
            BusinessException { 

         CourseActionForm courseForm = (CourseActionForm) form;
         String pageNumStr = request.getParameter("pageNumber");

//可以把页树也封装到formBean中,页面放一个隐藏字段存放page
           if (pageNumStr == null) {
               pageNumStr = "1";
           }
         pageNumber = Integer.parseInt(pageNumStr);
        Map map = new HashMap();
        map.put("provincecode",courseForm.getProvincecode());
        map.put("citycode",courseForm.getCitycode());
        map.put("recommendernum",courseForm.getRecommendernum());
        map.put("coursename",courseForm.getCoursename());
        Page page = this.getICourseService().queryCourseByPage(pageNumber,pageSize,map);
        request.setAttribute("Page",page);
        String path = request.getRequestURI();
        request.setAttribute("myPageURL", path+"?method=list");
        request.setAttribute("formName","courseForm");

//把当前action路径和form的名称传到页面 用于分页跳转

//主要目地是为了分离PageBar.jsp 也就是分页跳转导航条 便于通用
        return mapping.findForward("success"); //程序出口 返回到页面
    }

    private int pageNumber = 1;
    private int pageSize = 5;

//取得service实例
    private ICourseService getICourseService() {
        return (ICourseService) ProxyService.
                getBusinessService(
                        "CourseService");
    }

}

 

页面: courselist.jsp

 

<%@ page contentType="text/html; charset=gb2312" %>
<%@ page import="java.util.*"%>
<%@ page import="cn.loen.platform.util.page.Page"%>

<%

Page myPage = (Page)request.getAttribute("Page");

int lastPageNumber = 0;//总页数
int nextPageNumber = 0;//下页
int pageSize = 0;//每页记录数
int previoutPageNumber = 0;//上页
List orderlist = new ArrayList();//数据
int firstElement = 0;//当前第一条
int lastElement = 0;//当前最后一条
int pageNum = 0;//当前第几页
int totalElement = 0;//总记录数
if (myPage != null){
 lastPageNumber = myPage.getLastPageNumber();//总页数
 nextPageNumber = myPage.getNextPageNumber();//下页
 pageSize = myPage.getPageSize();//每页记录数
  previoutPageNumber = myPage.getPreviousPageNumber();//上页
 orderlist = myPage.getThisPageElements();//数据
 firstElement = myPage.getThisPageFirstElementNumber();//当前第一条
 lastElement = myPage.getThisPageLastElementNumber();//当前最后一条
 pageNum = myPage.getThisPageNumber();//当前第几页
 totalElement = myPage.getTotalNumberOfElements();//总记录数

//这里就是HibernatePage.java与Page.java的用处

//page = new HibernatePage(querylist, total, pageNumber, pageSize); 把list,总数量,当前页数,每页数量 都封装到page中
}

String pageURL = (String)request.getAttribute("myPageURL");
String formName = (String)request.getAttribute("formName");

%>

<table border="0"  cellspacing="0"  cellpadding="0"  width="80%" >
<tr>
  <td>共<%=totalElement%>条/每页<%=pageSize%>条 第<%=pageNum%>页/共<%=lastPageNumber%>页</td>
  <td>
    <div align="right">[<a href="javascript:gotoPage(1)">首页</a>][<a href="javascript:gotoPage(<%=previoutPageNumber%>)">上一页</a>][<a href="javascript:gotoPage(<%=nextPageNumber%>)">下一页</a>][<a href="javascript:gotoPage(<%=lastPageNumber%>)">末页</a>]
      转第
      <select name="jump" onchange="jumpPage(this)">
      <%for (int i = 1; i <= lastPageNumber; i++) {
        if (i == pageNum) {%>
          <option selected value="<%=i%>"><%=i%></option>
          <%}
          else{%>
          <option value="<%=i%>"><%=i%></option>
          <%}
        }%>
      </select>
      页
    </div></td>
  </tr>
</table>

<SCRIPT LANGUAGE="JavaScript" type="">
function jumpPage(selObj){
document.forms.<%=formName%>.action="<%=pageURL%>&pageNumber="+selObj.options[selObj.selectedIndex].value;
document.forms.<%=formName%>.submit();
}
function gotoPage(pageNumber){
document.forms.<%=formName%>.action="<%=pageURL%>&pageNumber="+pageNumber;
document.forms.<%=formName%>.submit();
}
</SCRIPT>

 

注意:在formBean的reset方法中要把查询条件的null转化为" " 或者在Action Servlet中转换

public class CourseActionForm extends ValidatorForm {
    private String address;
    private String citycode;
    private String courseid;
    private String coursename;
    private String designer;
    private String fax;
    private String holenumber;
    private String provincecode;
    private String tel;
    private String typegreens;
    private String zipcode;
    private String remarkxml;
    private FormFile smallpicup;
    private String smallpic;
    private String recommendernum;
    public String getAddress() {
        return address;
    }

    public void setAddress(String address) {
        this.address = address;
    }

    public void setZipcode(String zipcode) {
        this.zipcode = zipcode;
    }

    public void setTypegreens(String typegreens) {
        this.typegreens = typegreens;
    }

    public void setTel(String tel) {
        this.tel = tel;
    }

    public void setProvincecode(String provincecode) {
        this.provincecode = provincecode;
    }

    public void setHolenumber(String holenumber) {
        this.holenumber = holenumber;
    }

    public void setFax(String fax) {
        this.fax = fax;
    }

    public void setDesigner(String designer) {
        this.designer = designer;
    }

    public void setCoursename(String coursename) {
        this.coursename = coursename;
    }

    public void setCourseid(String courseid) {
        this.courseid = courseid;
    }

    public void setCitycode(String citycode) {
        this.citycode = citycode;
    }

    public void setRemarkxml(String remarkxml) {
        this.remarkxml = remarkxml;
    }

    public void setSmallpicup(FormFile smallpicup) {
        this.smallpicup = smallpicup;
    }

    public void setSmallpic(String smallpic) {
        this.smallpic = smallpic;
    }

    public void setRecommendernum(String recommendernum) {
        this.recommendernum = recommendernum;
    }

    public String getCitycode() {
        return citycode;
    }

    public String getCourseid() {
        return courseid;
    }

    public String getCoursename() {
        return coursename;
    }

    public String getDesigner() {
        return designer;
    }

    public String getFax() {
        return fax;
    }

    public String getHolenumber() {
        return holenumber;
    }

    public String getProvincecode() {
        return provincecode;
    }

    public String getTel() {
        return tel;
    }

    public String getTypegreens() {
        return typegreens;
    }

    public String getZipcode() {
        return zipcode;
    }

    public String getRemarkxml() {
        return remarkxml;
    }

    public FormFile getSmallpicup() {
        return smallpicup;
    }

    public String getSmallpic() {
        return smallpic;
    }

    public String getRecommendernum() {
        return recommendernum;
    }

    public ActionErrors validate(ActionMapping actionMapping,
                                 HttpServletRequest httpServletRequest) {
        String parameter = actionMapping.getParameter();
        String paramValue = httpServletRequest.getParameter(parameter);
        parameter = httpServletRequest.getParameter("method");
        if (paramValue.equals("save") || paramValue.equals("update")) {
            ActionErrors errors = super.validate(actionMapping,
                                                 httpServletRequest);
            return errors;

       //如果你希望用户必须输入一个条件才返回相应的记录集 要不就返回null 你可以在这里进行客户端控制
        } else {
            return null;
        }
    }

    public void reset(ActionMapping actionMapping,
                      HttpServletRequest servletRequest) {
        this.provincecode=this.provincecode==null?"":this.provincecode;
        this.citycode=this.citycode==null?"":this.citycode;
        this.recommendernum=this.recommendernum==null?"":this.recommendernum;
        this.coursename=this.coursename==null?"":this.coursename;

//如果是Integer对象 就转化为0 与struts机制一样 hql也是 :xx=0

//如果你希望用户必须输入一个条件才返回相应的记录集 要不就返回null 你可以在这里进行服务端控制或者servlet控制(servlet控制更有效率)
    }
}

 

以上就是完成的分页例子

大家只需要2个地方自己写 1:hql查询语句  2:Map 的查询参数