用hibernate实现分页

1.用到了两个类，一个pojo：maps.Maps，一个dao：maps.MapsDAO

2.主要起作用的核心代码两行：

   queryObject.setFirstResult(pageSize*pageNumber);
    queryObject.setMaxResults(pageSize);

3.全部代码：

package maps;

/**
* Maps entity.
*
* @author MyEclipse Persistence Tools
*/

public class Maps implements java.io.Serializable {

// Fields

private Long mapId;
private Building building;
private Floor floor;
private Region region;
private MapType mapType;
private UnitInfo unitInfo;
private Room room;
private SubRegion subRegion;
private String mapName;
private String mapAddr;
private Integer mapLayer;
private String mapBak;

// Constructors

/** default constructor */
public Maps() {
}

/** minimal constructor */
public Maps(String mapName, String mapAddr, Integer mapLayer) {
   this.mapName = mapName;
   this.mapAddr = mapAddr;
   this.mapLayer = mapLayer;
}

/** full constructor */
public Maps(Building building, Floor floor, Region region, MapType mapType,
    UnitInfo unitInfo, Room room, SubRegion subRegion, String mapName,
    String mapAddr, Integer mapLayer, String mapBak) {
   this.building = building;
   this.floor = floor;
   this.region = region;
   this.mapType = mapType;
   this.unitInfo = unitInfo;
   this.room = room;
   this.subRegion = subRegion;
   this.mapName = mapName;
   this.mapAddr = mapAddr;
   this.mapLayer = mapLayer;
   this.mapBak = mapBak;
}

// Property accessors

public Long getMapId() {
   return this.mapId;
}

public void setMapId(Long mapId) {
   this.mapId = mapId;
}

public Building getBuilding() {
   return this.building;
}

public void setBuilding(Building building) {
   this.building = building;
}

public Floor getFloor() {
   return this.floor;
}

public void setFloor(Floor floor) {
   this.floor = floor;
}

public Region getRegion() {
   return this.region;
}

public void setRegion(Region region) {
   this.region = region;
}

public MapType getMapType() {
   return this.mapType;
}

public void setMapType(MapType mapType) {
   this.mapType = mapType;
}

public UnitInfo getUnitInfo() {
   return this.unitInfo;
}

public void setUnitInfo(UnitInfo unitInfo) {
   this.unitInfo = unitInfo;
}

public Room getRoom() {
   return this.room;
}

public void setRoom(Room room) {
   this.room = room;
}

public SubRegion getSubRegion() {
   return this.subRegion;
}

public void setSubRegion(SubRegion subRegion) {
   this.subRegion = subRegion;
}

public String getMapName() {
   return this.mapName;
}

public void setMapName(String mapName) {
   this.mapName = mapName;
}

public String getMapAddr() {
   return this.mapAddr;
}

public void setMapAddr(String mapAddr) {
   this.mapAddr = mapAddr;
}

public Integer getMapLayer() {
   return this.mapLayer;
}

public void setMapLayer(Integer mapLayer) {
   this.mapLayer = mapLayer;
}

public String getMapBak() {
   return this.mapBak;
}

public void setMapBak(String mapBak) {
   this.mapBak = mapBak;
}

}

/******************************************************************************************************/

package maps;

import java.util.List;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.hibernate.LockMode;
import org.hibernate.Query;
import org.hibernate.criterion.Example;

/**
* A data access object (DAO) providing persistence and search support for Maps
* entities. Transaction control of the save(), update() and delete() operations
* can directly support Spring container-managed transactions or they can be
* augmented to handle user-managed Spring transactions. Each of these methods
* provides additional information for how to configure it for the desired type
* of transaction control.
*
* @see maps.Maps
* @author MyEclipse Persistence Tools
*/

public class MapsDAO extends BaseHibernateDAO {
private static final Log log = LogFactory.getLog(MapsDAO.class);
// property constants
public static final String MAP_NAME = "mapName";
public static final String MAP_ADDR = "mapAddr";
public static final String MAP_LAYER = "mapLayer";
public static final String MAP_BAK = "mapBak";

public void save(Maps transientInstance) {
   log.debug("saving Maps instance");
   try {
    getSession().save(transientInstance);
    log.debug("save successful");
   } catch (RuntimeException re) {
    log.error("save failed", re);
    throw re;
   }
}

public void delete(Maps persistentInstance) {
   log.debug("deleting Maps instance");
   try {
    getSession().delete(persistentInstance);
    log.debug("delete successful");
   } catch (RuntimeException re) {
    log.error("delete failed", re);
    throw re;
   }
}

public Maps findById(java.lang.Long id) {
   log.debug("getting Maps instance with id: " + id);
   try {
    Maps instance = (Maps) getSession().get("maps.Maps", id);
    return instance;
   } catch (RuntimeException re) {
    log.error("get failed", re);
    throw re;
   }
}

public List findByExample(Maps instance) {
   log.debug("finding Maps instance by example");
   try {
    List results = getSession().createCriteria("maps.Maps").add(
      Example.create(instance)).list();
    log.debug("find by example successful, result size: "
      + results.size());
    return results;
   } catch (RuntimeException re) {
    log.error("find by example failed", re);
    throw re;
   }
}

public List findByProperty(String propertyName, Object value) {
   log.debug("finding Maps instance with property: " + propertyName
     + ", value: " + value);
   try {
    String queryString = "from Maps as model where model."
      + propertyName + "= ?"+"order by mapType";
    Query queryObject = getSession().createQuery(queryString);
    queryObject.setParameter(0, value);
    return queryObject.list();
   } catch (RuntimeException re) {
    log.error("find by property name failed", re);
    throw re;
   }
}
public List findByMapNameUseLike(String name){
   log.debug("finding Maps instance with property: " + MAP_NAME
     + ", value: " + name);
   try {
    String queryString = "from Maps as model where model."
      + MAP_NAME + " LIKE ? "+"order by mapType";
    Query queryObject = getSession().createQuery(queryString);
    queryObject.setParameter(0, "%"+name+"%");
    return queryObject.list();
   } catch (RuntimeException re) {
    log.error("find by property name failed", re);
    throw re;
   }
}
public List findAllListByPage(int pageSize,int pageNumber){
   log.debug("finding Maps instance with pageSize and pageNumber");
   try{
    String queryString="from Maps order by id";
    Query queryObject=getSession().createQuery(queryString);
    queryObject.setFirstResult(pageSize*pageNumber);
    queryObject.setMaxResults(pageSize);
    return queryObject.list();
   }catch(RuntimeException re){
    log.error("find all failed");
    throw re;
   }
}
public List findByMapName(Object mapName) {
   return findByProperty(MAP_NAME, mapName);
}

public List findByMapAddr(Object mapAddr) {
   return findByProperty(MAP_ADDR, mapAddr);
}

public List findByMapLayer(Object mapLayer) {
   return findByProperty(MAP_LAYER, mapLayer);
}

public List findByMapBak(Object mapBak) {
   return findByProperty(MAP_BAK, mapBak);
}

public List findAll() {
   log.debug("finding all Maps instances");
   try {
    String queryString = "from Maps";
    Query queryObject = getSession().createQuery(queryString);
    return queryObject.list();
   } catch (RuntimeException re) {
    log.error("find all failed", re);
    throw re;
   }
}

public Maps merge(Maps detachedInstance) {
   log.debug("merging Maps instance");
   try {
    Maps result = (Maps) getSession().merge(detachedInstance);
    log.debug("merge successful");
    return result;
   } catch (RuntimeException re) {
    log.error("merge failed", re);
    throw re;
   }
}

public void attachDirty(Maps instance) {
   log.debug("attaching dirty Maps instance");
   try {
    getSession().saveOrUpdate(instance);
    log.debug("attach successful");
   } catch (RuntimeException re) {
    log.error("attach failed", re);
    throw re;
   }
}

public void attachClean(Maps instance) {
   log.debug("attaching clean Maps instance");
   try {
    getSession().lock(instance, LockMode.NONE);
    log.debug("attach successful");
   } catch (RuntimeException re) {
    log.error("attach failed", re);
    throw re;
   }
}
}

/*************************************************************************************************************/

package test;

import maps.*;

/**
* @说明 本方法用hibernate实现分页
* @author 蒋明原
* @see maps.MapsDAO
* @see maps.Maps
* @version 1.0
*/
public class MapsFindAllByPage {

/**
* @param pageSize
*            页面数据大小
*/
public static void main(String[] args) {
   // TODO Auto-generated method stub
   MapsDAO dao = new MapsDAO();
   int pageSize = 3;
   System.out.println("sizeOf dao'list: " + dao.findAll().size());
   for (int i = 0; i < ((dao.findAll().size()        .findAll().size()
        / pageSize : (dao.findAll().size() / pageSize) + 1)); i++) {
    java.util.List list = dao.findAllListByPage(pageSize, i);
    java.util.Iterator it = list.iterator();
    while (it.hasNext()) {
     Maps map = (Maps) it.next();
     System.out.println(map.getMapId() + " " + map.getMapName());
    }
    System.out.println("________________________________");
   }

}

}
/***********************************************************************************************************/