Hibernate的分页查询 PageObject完整版

package com.google.util;

import java.util.ArrayList;
import java.util.List;

import org.hibernate.Query;
import org.hibernate.Session;
import org.hibernate.Transaction;

/**
 * 定义一个处理分页查询的类
 * @author Administrator
 *
 */
public class PageObject {

	private int totalRecord = 0;//总记录数
	private int pageSize = 10;//一页显示的条数
	private int currentPage = 1;//当前页
	private int totalPage = 1;//总页数
	private String hql; //执行查询的语句
	private ArrayList params; //hql参数
	private List result; //返回结果集
	
	//创建构造器
	public PageObject(){
		
	}
	/**
	 * 固定类的分页  from ClassPO
	 * @param hql 查询语句
	 * @param param  查询参数
	 * @param pageSize 每页的条数
	 * @param currentPage 当前页
	 */
	public PageObject(String hql, ArrayList params, int pageSize, int currentPage){
		if(currentPage <=0 ){
			this.currentPage = 1;
		}else{
			this.currentPage = currentPage;
		}
		if(pageSize <= 0){
			this.pageSize = 10;
		}else{
			this.pageSize = pageSize;
		}
		this.hql = hql;
		this.params = params;
		getCount();
		result();
	}
	public int getTotalRecord() {
		return totalRecord;
	}
	public int getPageSize() {
		return pageSize;
	}

	public int getCurrentPage() {
		return currentPage;
	}

	public int getTotalPage() {
		return totalPage;
	}

	public ArrayList getParams() {
		return params;
	}
	public void setParams(ArrayList params) {
		this.params = params;
	}
	
	public List getResult() {
		return result;
	}
	public void setResult(List result) {
		this.result = result;
	}
	/**
	 * 获取条数信息
	 */
	public void getCount(){
		Session session = null;
		List list = null;
		try {
			session = HibernateUtil.openSession();
			if(session == null){
				System.out.println("--------------------------");
			}
			String str = new String();
			str = "select count(*) ";
			//判断hql是不是select or SELECT开始的
			if(hql.toLowerCase().trim().indexOf("select") == 0){
				//如果是select 语句开始的，则在str中添加select count(*) from( hql )
				//获取from开始的字串
				str += hql.substring(hql.toLowerCase().indexOf("from"));
				System.out.println("是select 开始的hql "+ str);
			}else{
				//如果是一个PO from CPO,则只是添加select count(*) 即可
				str += hql;
				System.out.println("不是select 开始的hql "+ str);
			}
			System.out.println("====================="+str);
			
			Query query = session.createQuery(str);
			
			query = addParams(query, params);
			
			//设置总记录数
			totalRecord = Integer.parseInt(query.uniqueResult().toString());
//			this.setTotalRecord(Integer.parseInt(query.uniqueResult().toString()));
			//设置总页数
			totalPage = (totalRecord-1)/pageSize+1;
//			this.setTotalPage((totalRecord-1)/pageSize+1);
		} catch (Exception e) {
			throw new RuntimeException("设置页面信息："+e.getMessage());
		}finally{
			if(session != null && session.isOpen()){
				session.close();
			}
		}
	}
	//执行查询
	public void result(){
		Session session = null;
		Transaction tx = null;
		List list = null;
		try {
			session = HibernateUtil.getCurrentSession();
			tx = session.beginTransaction();
			System.out.println(this.hql);
			Query query = session.createQuery(this.hql);
			
			String str = "select count(*) from (";
			str += this.hql;
			str += ")";
			query = addParams(query, params);

			list = query.setFirstResult((currentPage-1)*pageSize).setMaxResults(pageSize).list();
			this.setResult(list);
			tx.commit();
		} catch (Exception e) {
			if(tx!=null){
				tx.rollback();
			}
			e.printStackTrace();
			throw new RuntimeException("----"+e.getMessage());
		}finally{
			if(session != null && session.isOpen()){
				session.close();
			}
		}
	}
	
	public Query addParams(Query query, ArrayList params){
		//添加参数到hql
		if(params!=null && params.size() >0){
			for(int i=0; i < params.size(); i++){
				query.setParameter(i, params.get(i));
			}
		}
		return query;
	}
}

//附带HibernateUtil.java

package com.google.util;


//import org.hibernate.Session;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;


import org.hibernate.Query;
import org.hibernate.Session;
import org.hibernate.SessionFactory;
import org.hibernate.cfg.Configuration;


final public class HibernateUtil {
	
	private static SessionFactory sessionFactory = null;
	private static ThreadLocal<Session> threadLocal = new ThreadLocal<Session>();
	
	public HibernateUtil(){
		
	}
	static{
		sessionFactory = new Configuration().configure().buildSessionFactory();
	}
	//获取全新的session
	public static Session openSession(){
		return sessionFactory.openSession();
	}
	
	//获取和线程关联的session
	public static Session getCurrentSession(){
		
		Session session = threadLocal.get();
		//判断是否得到
		//add by yyy  || !session.isOpen()
		if(session == null || !session.isOpen()){
			session = sessionFactory.openSession();
			//session对象设置到threadLocal -- 相当于session和线程绑定
			threadLocal.set(session);
		}
		return session;
	}
	
	/**
	 * 查询方法
	 */
	public static List executeQuery1(String hql, String[] parameters){
		Session session = null;
		List list = null;
		try {
			session = openSession();
			Query query = session.createQuery(hql);
			if(parameters != null && parameters.length > 0){
				for(int i=0; i< parameters.length; i++){
					query.setParameter(i, parameters[i]);
				}
			}
			list = query.list();
			
		} catch (Exception e) {
			e.getStackTrace();
			throw new RuntimeException(e.getMessage());
		}finally{
			if(session != null && session.isOpen()){
				session.close();
			}
		}
		return list;
	}
	/**
	 * 同意的查询方法：参数使用ArrayList
	 */
	public static List executeQuery(String hql, ArrayList al){
		
		Session session = null;
		List list = null;
		try {
			session = openSession();
			Query query = session.createQuery(hql);
			//注入参数
			if(al!=null && al.size() > 0){
				for(int i=0; i < al.size(); i++){
					query.setParameter(i, al.get(i));
				}
				System.out.println(al.toString());
			}
		//执行查询
			list = query.list();
		} catch (Exception e) {
			e.printStackTrace();
			throw new RuntimeException("Util executeQuery"+e.getMessage());
		}finally{
			if(session != null && session.isOpen()){
				session.close();
			}
		}
		return list;
	}
	
	/**
	 * 同意的分页查询方法 没有确定的PO
	 */
	public static Map executeQueryByPage(String hql, ArrayList parameter, int pageSize, int currentPage){
		
		Session session = null;
		int pageCount = 1;//总页数
		int totalCount = 0;//总记录数
		//pageSize一页显示的条数
		//currentPage 当前页
		List<Object[]> result = null;
		HashMap map = new HashMap();
		try {
			session = openSession();
			Query query = session.createQuery(hql);
			if(parameter != null && parameter.size() > 0){
				for(int i=0; i< parameter.size(); i++){
					query.setParameter(i, parameter.get(i));
				}
			}
			//获取总记录数
			totalCount = query.list().size();
			System.out.println(totalCount);
			//计算总页数
			if(totalCount >=1){
				pageCount = (totalCount-1)/pageSize+1;
			}
			
			//先测试分页情况
		/*	for(int i=1; i<=pageCount; i++){
//				System.out.println("------------第"+i+"页----------------");
				result = query.setFirstResult((i-1)*pageSize).setMaxResults(i*pageSize).list();
			}*/
			/*if(result.size()>0){
				for(int k = 0; k < result.size(); k++){
					Object[] obj = result.get(k);
					for(int j=0; j< obj.length; j++){
						System.out.print(obj[j].toString()+" ");
					}
					System.out.println();
				}
			}*/
			result = query.setFirstResult((currentPage-1)*pageSize).setMaxResults(pageSize).list();
			map.put("TOTAL_COUNT", totalCount);
			map.put("RESULT", result);
			map.put("PAGE_COUNT", pageCount);
		} catch (Exception e) {
			// TODO: handle exception
			e.printStackTrace();
		}
		return map;
	}
}