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[Java教程]Java_Web三大框架之Hibernate+jsp+HQL分页查询


分页查询无处不在。使用Hibernate+jsp+HQL进行分页查询。

第一步:编写房屋实体类和House.hbm.

/* * 房屋实体类 */public class House {  private int id;//房屋id    private HouseType type;//房屋类型  private Users2 user;//用户  private Street street;//街道    private String title;//标题  private String description;//描述  private String fdate;//日期  private String price;//价格  private String contact;//面积//省略get和set方法}

<??><!DOCTYPE hibernate-mapping PUBLIC   "-//Hibernate/Hibernate Mapping DTD 3.0//EN"  "http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd"><hibernate-mapping  package="entity">  <class name="House" table="House">    <id name="id">      <generator class="increment"/>    </id>    <!--外键--> <many-to-one name="type" column="type_id" cascade="save-update" />  <many-to-one name="user" column="user_id" cascade="save-update" />   <many-to-one name="street" column="street_id" cascade="save-update" />    <property name="title" />    <property name="description" />    <property name="fdate" />    <property name="price" />    <property name="contact" />      </class></hibernate-mapping>

第二步:编写hibernate.cfg.

<!DOCTYPE hibernate-configuration PUBLIC  "-//Hibernate/Hibernate Configuration DTD 3.0//EN"  "http://hibernate.sourceforge.net/hibernate-configuration-3.0.dtd"><hibernate-configuration>  <session-factory name="foo">    <!-- 数据库方言 -->    <property name="dialect">      org.hibernate.dialect.OracleDialect    </property>    <!-- 连接数据库Url -->    <property name="hibernate.connection.url">      jdbc:oracle:thin:@localhost:1521:orcl    </property>    <!-- 连接驱动 -->    <property name="hibernate.connection.driver_class">      oracle.jdbc.driver.OracleDriver    </property>    <!-- 用户名 -->    <property name="hibernate.connection.username">epet</property>    <!-- 密码 -->    <property name="hibernate.connection.password">123456</property>        <!-- 在控制台打印sql信息 -->    <property name="show_sql">true</property>    <!-- 创建表结构 -->    <property name="hibernate.hbm2ddl.auto">update</property>      <!-- 配置映射信息 -->      <mapping resource="entity/House.hbm. />          </session-factory></hibernate-configuration>

第三步:HibernateUtil+fenye.java分页语句

package com.msit.hibernate.HibernateUtil;import org.hibernate.Session;import org.hibernate.SessionFactory;import org.hibernate.cfg.Configuration;public class HibernateUtil {    private HibernateUtil(){      };    public static SessionFactory SessionFactory = null;    static{    //hibernate    Configuration cf = new Configuration();    cf.configure();    SessionFactory = cf.buildSessionFactory();//DriverManager.getconnection()    //Session session = SessionFactory.openSession();  }    public static Session getSession(){        return SessionFactory.openSession();  }    public static void closeSession(Session session){    if(session!=null){      session.clear();    }  }}

 

package Dao;import java.util.List;import org.hibernate.Query;import org.hibernate.Session;import org.hibernate.Transaction;import com.msit.hibernate.HibernateUtil.HibernateUtil;import entity.House;/* * 分页 */public class fenye {  //查询所有房屋  public List<House> selecthouse() {    // TODO Auto-generated method stub     Session session = HibernateUtil.getSession();    //开启事物     Transaction tran=session.beginTransaction();         String hql="from House";     Query q=session.createQuery(hql);          List<House> list = q.list();     return list;     }  //房屋总数除于要分的条数  public int getTotalPages(int count,int pageSize){    int totalpages=0;    totalpages=(count%pageSize==0)?(count/pageSize):(count/pageSize+1);    return totalpages;  }  //获取房屋总条数  public int getConut(){ Session session = HibernateUtil.getSession();     Transaction tran=session.beginTransaction();    String hql="select count(*) from House";    Query q=session.createQuery(hql);    List list = q.list();    String li=list.get(0).toString();    Integer count=Integer.parseInt(li);    return count;  }    public List<House> selechouse(int pageIndex,int pageSize){    // TODO Auto-generated method stub     Session session = HibernateUtil.getSession();     //开启事物     Transaction tran=session.beginTransaction();     String hql="from House";     Query query=session.createQuery(hql);     query.setFirstResult((pageIndex-1)*pageSize);     query.setMaxResults(pageSize);     List<House> result=query.list();    return result;  }}

jsp页面:

 

<%//==============分页===============  //设置新闻显示条数  int pageSize=4;//实例化fenye newxw=new fenye(); //获取数据库有多少条数据int count=newxw.getConut();//获取页码String page1=request.getParameter("pageIndex");//得到具体要分的页int pag=newxw.getTotalPages(newxw.getConut(),pageSize);//得到当前页int pageIndex=0;//判断得到的值是否有值if(page1==null){  pageIndex=1;    //查询  }else{  //把当前页赋值给pageIndex  pageIndex=Integer.parseInt(page1);   //判断当前页是否为最大页  if(pageIndex>pag){    pageIndex=pag;  }  }List<House> list=newxw.selechouse(pageIndex,pageSize);request.setAttribute("list",list);%><%  HouseBiz hou=new HouseBizImpl();  List<House> hoi=hou.selecthouse();  request.setAttribute("list",list);%>
<c:forEach var="mind" items="${requestScope.list}">

/
省略
显示数据/

</c:forEach >

<%
//判断当前页是否为末页
if(pageIndex>1){
%>
<LI><a href="list.jsp?pageIndex=<%=1 %>"> 首页</a></LI>
<LI> <a href="list.jsp?pageIndex=<%=pageIndex-1%>"> 上一页 </a></LI>

<%
}
//判断当前页是否为末页
if(pageIndex<pag){
%>
<LI> <a href="list.jsp?pageIndex=<%=pageIndex+1 %>"> 下一页</a></LI>
<LI> <a href="list.jsp?pageIndex=<%=pag%>"> 末页 </a></LI>

<%
}

%>


</UL>


<SPAN
class=total>[<%=pageIndex %>/<%=pag%>]页</SPAN> </DIV></DIV>