placarddaoimpl.java

SSH 的分页...是新手的一个不错例子.

package com.placard.usermanage.dao.impl;

import java.util.ArrayList;
import java.util.Date;
import java.util.List;
import java.util.Set;

import org.hibernate.Criteria;
import org.hibernate.criterion.Expression;
import org.hibernate.criterion.Order;
import org.hibernate.criterion.ProjectionList;
import org.hibernate.criterion.Projections;

import com.placard.core.common.hibernate.BaseHibernateDAO;
import com.placard.usermanage.dao.ModuleDAO;
import com.placard.usermanage.dao.PlacardDAO;
import com.placard.usermanage.model.Module;
import com.placard.usermanage.model.Placard;

public class PlacardDAOImpl extends BaseHibernateDAO implements PlacardDAO {

	public Placard getPlacardById(int id) {
		return null;
	}
	public List<Placard> getPlacardByPage(int startIndex , int length, Placard placardExample) {
		ModuleDAO moduleDAO = new ModuleDAOImpl();
		Criteria criteria = super.getSession().createCriteria(Placard.class);
		ProjectionList projectionList = Projections.projectionList();
		projectionList.add(Projections.property("id"));
		projectionList.add(Projections.property("title"));
		projectionList.add(Projections.property("publisher"));
		projectionList.add(Projections.property("submitTime"));
		projectionList.add(Projections.property("status"));
		criteria.setProjection(projectionList);
		//条件查询
		if(placardExample!=null){
			String title = placardExample.getTitle();
			if(title!=null){
				criteria.add(Expression.like("title","%"+title+"%" ));
			}
			
			String publisher = placardExample.getPublisher();
			if(publisher!=null){
				criteria.add(Expression.like("publisher","%"+publisher+"%"));
			}
			Set<Module> modules = placardExample.getModules();
			if(modules==null || modules.size()!=0){
				int moduleId = modules.iterator().next().getId();
				criteria.createAlias("modules", "module").add(Expression.eq("module.id", moduleId));
			}
		}
		criteria.addOrder(Order.desc("submitTime"));
		criteria.setFirstResult(startIndex);
		criteria.setMaxResults(length);
		List tempList = criteria.list();
		List<Placard> placardList = new ArrayList<Placard>();
		if(tempList!=null){
			for(int i=0;i<tempList.size();i++){
				Object[] tempObj =  (Object[])tempList.get(i);
				Placard placard = new Placard();
				placard.setId((Integer)tempObj[0]);
				placard.setTitle((String)tempObj[1]);
				placard.setPublisher((String)tempObj[2]);
				placard.setSubmitTime((Date)tempObj[3]);
				placard.setStatus((Byte)tempObj[4]);
				//取得该公告的所属模块
				Set modules = moduleDAO.getModulesByPlacard((Integer)tempObj[0]);
				placard.setModules(modules);
				placardList.add(placard);
			}
			return placardList;
		}
		return null;
	}
	
	public int getPlacardLength(Placard placardExample){
		Criteria criteria = super.getSession().createCriteria(Placard.class);
		criteria.setProjection(Projections.rowCount());
		//条件查询
		if(placardExample!=null){
			String title = placardExample.getTitle();
			if(title!=null){
				criteria.add(Expression.like("title","%"+title+"%" ));
			}
			
			String publisher = placardExample.getPublisher();
			if(publisher!=null){
				criteria.add(Expression.eq("publisher",publisher));
			}
			Set<Module> modules = placardExample.getModules();
			if(modules==null || modules.size()!=0){
				int moduleId = modules.iterator().next().getId();
				criteria.createAlias("modules", "module").add(Expression.eq("module.id", moduleId));
			}
		}
		List<Integer> countList = criteria.list();
		return countList.get(0);
	}
}