北大青鸟学员一枚，最近做了几次测试。都是有关于分页查询和动态查询的题目。可是我实在不会。请问大神，SSH中如何实现分页查询和动态查询呢？
首先是动态查询总页数
String hql = "select count(h.id) from Housex h where 1=1";
if(hc.getDid()!=null){
hql+=" and h.streetx.districtx.id=:did";
}
if(hc.getId()!=null){
hql+=" and h.id=:id;";
}
if(hc.getLowfloorage()!=null){
hql+=" and h.floorage>=:lowfloorage";
}
if(hc.getLowprice()!=null){
hql+=" and h.pricex>=:lowprice";
}
if(hc.getSid()!=null){
hql+=" and h.streetx.id=:sid";
}
if(hc.getTid()!=null){
hql+=" and h.typex.id=:tid";
}
if(hc.getTitle()!=null){
hql+=" and h.titlex like :title";
}
if(hc.getUid()!=null){
hql+=" and h.usersx.id=:uid";
}
if(hc.getUpfloorage()!=null){
hql+=" and h.floorage<:upfloorage";
}
if(hc.getUpprice()!=null){
hql+=" and h.pricex<:upprice";
}
Query q = s.createQuery(hql);
q.setProperties(hc);
int tiao = Integer.parseInt(q.list().get(0).toString());
return tiao%pageSize==0?tiao/pageSize:tiao/pageSize+1;
然后是动态查询list
public List<Housex> selectHousexByCondition(Session s, HousexCondition hc,
int pageNo, int pageSize) {
String hql = "from Housex h inner join fetch h.usersx u inner join fetch h.streetx s inner join fetch h.typex t inner join fetch s.districtx d where 1=1";
if(hc.getDid()!=null){
hql+=" and d.id=:did";
}
if(hc.getId()!=null){
hql+=" and h.id=:id;";
}
if(hc.getLowfloorage()!=null){
hql+=" and h.floorage>=:lowfloorage";
}
if(hc.getLowprice()!=null){
hql+=" and h.pricex>=:lowprice";
}
if(hc.getSid()!=null){
hql+=" and s.id=:sid";
}
if(hc.getTid()!=null){
hql+=" and t.id=:tid";
}
if(hc.getTitle()!=null){
hql+=" and h.titlex like :title";
}
if(hc.getUid()!=null){
hql+=" and u.id=:uid";
}
if(hc.getUpfloorage()!=null){
hql+=" and h.floorage<:upfloorage";
}
if(hc.getUpprice()!=null){
hql+=" and h.pricex<:upprice";
}
Query q = s.createQuery(hql);
q.setProperties(hc);
q.setFirstResult((pageNo-1)*pageSize);
q.setMaxResults(pageSize);
return q.list();
}
这是hibernate的做法，如果是mybatis得自己写查询语句，但是mybatis有反向工程的代码，很好使，建议楼主去网上查查
查页数的少一点，这是全的
public int getPagesByCondition(Session s, int pageSize, HousexCondition hc) {
String hql = "select count(h.id) from Housex h where 1=1";
if(hc.getDid()!=null){
hql+=" and h.streetx.districtx.id=:did";
}
if(hc.getId()!=null){
hql+=" and h.id=:id;";
}
if(hc.getLowfloorage()!=null){
hql+=" and h.floorage>=:lowfloorage";
}
if(hc.getLowprice()!=null){
hql+=" and h.pricex>=:lowprice";
}
if(hc.getSid()!=null){
hql+=" and h.streetx.id=:sid";
}
if(hc.getTid()!=null){
hql+=" and h.typex.id=:tid";
}
if(hc.getTitle()!=null){
hql+=" and h.titlex like :title";
}
if(hc.getUid()!=null){
hql+=" and h.usersx.id=:uid";
}
if(hc.getUpfloorage()!=null){
hql+=" and h.floorage<:upfloorage";
}
if(hc.getUpprice()!=null){
hql+=" and h.pricex<:upprice";
}
Query q = s.createQuery(hql);
q.setProperties(hc);
int tiao = Integer.parseInt(q.list().get(0).toString());
return tiao%pageSize==0?tiao/pageSize:tiao/pageSize+1;
}
注意housexCondition是一个封装的条件类
///////////////////////////////////////////////////////////////////////////
package com.vfsd.dao.impl;
import java.io.Serializable;
import java.lang.reflect.ParameterizedType;
import java.lang.reflect.Type;
import java.sql.SQLException;
import java.util.List;
import javax.annotation.Resource;
import org.hibernate.HibernateException;
import org.hibernate.Query;
import org.hibernate.Session;
import org.hibernate.SessionFactory;
import org.springframework.orm.hibernate3.HibernateCallback;
import org.springframework.orm.hibernate3.support.HibernateDaoSupport;
import org.springframework.stereotype.Repository;
import com.vfsd.util.Pager;
@SuppressWarnings("rawtypes")
@Repository("baseDao")
public class BaseDaoImpl extends HibernateDaoSupport{
@Resource(name="sessionFactory")
private void setSf( SessionFactory sf){
super.setSessionFactory(sf);
}
private Class clazz;
{
Type type=this.getClass().getGenericSuperclass();
if(type instanceof ParameterizedType){
Type types[]=((ParameterizedType) type).getActualTypeArguments();
clazz=(Class) types[0];
}else{
clazz=Object.class;
}
}
/**
*
*
*/
@Override
public Pager findByDynaParam(final int pageNo,final int pageSize, final String hql, final Object dto) {
Pager pager=new Pager();
List list= this.getHibernateTemplate().executeFind(new HibernateCallback() {
@Override
public Object doInHibernate(Session session) throws HibernateException,
SQLException {
Query query=null;
try{
query=session.createQuery(hql);
}catch(Exception e){
e.printStackTrace();
}
query.setProperties(dto);
query.setFirstResult((pageNo-1)*pageSize).setMaxResults(pageSize);
return query.list();
}
});
pager.setRows(list);
pager.setTotal(getTotalByDynaParam(hql, dto));
return pager;
}
private int getTotalByDynaParam(final String hql, final Object dto) {
int index=hql.indexOf("from");
final String countHql="select count(*) "+hql.substring(index).replace("fetch", "");
List list=this.getHibernateTemplate().executeFind(new HibernateCallback() {
@Override
public Object doInHibernate(Session session) throws HibernateException,
SQLException {
Query query=session.createQuery(countHql).setProperties(dto);
return query.list();
}
});
if(list.size()>0){
return Integer.valueOf(list.get(0).toString());
}else{
return -1;
}
}
}
////////////////////////////////////////////////////////////////////////////////////
package com.vfsd.dao.impl;
import java.util.List;
import org.springframework.stereotype.Repository;
import com.vfsd.util.Pager;
/**
*
*/
@Repository("bbsDao")
public class BbsDaoImpl extends BaseDaoImpl{
//分页查询帖子
@SuppressWarnings("unchecked")
@Override
public Pager<Bbs> searchAll(int page, int rows, Bbs bbs) {
String hql=" from Bbs bbs1 where 1=1 ";
if(bbs!=null){
//附加条件
}
hql =hql+" order by bbs1.id desc ";
return this.findByDynaParam(page, rows, hql, bbs);
}
}
////////////////////////////////////////////////////////////////////////////
package com.vfsd.util;
import java.util.List;
public class Pager {
private List rows;
private int total;
public List getRows() {
return rows;
}
public void setRows(List rows) {
this.rows = rows;
}
public int getTotal() {
return total;
}
public void setTotal(int total) {
this.total = total;
}
}