Hibernate分页查询与泛型

package common.dao;

/**
* 分页功能
*/
public class Page
{
public final int DEFAULT_PAGESIZE = 15; // 每页记录数

public final int DEFAULT_PAGE = 1; // 默认显示第几页

// =========================================================================================

protected int count; // 总的记录数

protected int pageSize; // 每页记录数

protected int pageCount; // 总的页数

protected int page; // 本页页号

protected int start; // 起始记录下标(MySql从0开始)

// =========================================================================================
/**
* 构造方法
*
* @param nPageSize
*            每页记录数
* @param nPage
*            本页页号
*/
public Page(final int nPageSize, final int nPage)
{
pageSize = nPageSize; // 每页大小
page = nPage; // 本页页号
}

/**
* 构造方法 ,默认每页20条记录
*
* @param nPage
*            本页页号
*/
public Page(final int nPage)
{
pageSize = DEFAULT_PAGESIZE; // 每页大小
page = nPage; // 本页页号
}

/**
* 构造方法 ,默认每页20条记录,显示第一页
*
*/
public Page()
{
pageSize = DEFAULT_PAGESIZE; // 每页大小
page = DEFAULT_PAGE; // 本页页号
}

/**
* 分页初始化
*
* @param nCount
*            总的记录数
*/
public void init(final int nCount)
{
init(nCount, pageSize, page);
}

/**
* 分页初始化；记录总记录数，每页记录数，当前页，并计算总页数、本页大小和检测当前页是否有效
*
* @param nCount
*            总的记录数
* @param nPageSize
*            每页记录数
* @param nPage
*            本页页号
*/
public void init(final int nCount, final int nPageSize, final int nPage)
{
count = nCount; // 总的项数
page = nPage; // 本页页号
pageSize = nPageSize; // 每页大小
if (0 >= pageSize)
{
pageSize = DEFAULT_PAGESIZE;
}
pageCount = (nCount + pageSize - 1) / pageSize; // 计算总的页数

// 防止 Page 超范围并计算当前页大小
if (page > pageCount)
{
page = pageCount;
}
if (page < 1)
{
page = DEFAULT_PAGE;
}

start = min();
}

/**
* 计算起始记录下标(MySql从0开始)
*
* @return
*/
public int min()
{
final int max = page * pageSize - 1;
return max - pageSize + 1;
}

// public int max()
// {
// final int max = page * pageSize - 1;
// return max;
// }

/**
* 计算导航页(开始页号)
*
* @param nPageNav
*            导航页数
* @return 开始页号
*/
public final int CalcMinPage(final int nPageNav)
{
int min = page - (nPageNav / 2);
int max = page + (nPageNav / 2);
if (min < 1)
{
final int a = 0 - min;
min = 1;
max = max + a;
}
if (max > pageCount)
{
final int b = max - pageCount;
max = pageCount;
min = min - b < 1 ? 1 : min - b;
}
return min;
}

/**
* 计算导航页(结束页号)
*
* @param nPageNav
*            导航页数
* @return 结束页号
*/
public final int CalcMaxPage(final int nPageNav)
{
int min = page - (nPageNav / 2);
int max = page + (nPageNav / 2);
if (min < 1)
{
final int a = 0 - min;
min = 1;
max = max + a;
}
if (max > pageCount)
{
final int b = max - pageCount;
max = pageCount;
min = min - b < 1 ? 1 : min - b;
}
return max;
}

@Override
public String toString()
{
final StringBuffer sbf = new StringBuffer();
sbf.append(" 总的记录数:" + count);
sbf.append(" 每页记录数:" + pageSize);
sbf.append(" 总的页数:" + pageCount);
sbf.append(" 本页页号:" + page);
sbf.append(" 起始记录下标:" + start);
return sbf.toString();
}

public int getCount()
{
return count;
}

public void setCount(final int count)
{
this.count = count;
}

public int getPageSize()
{
return pageSize;
}

public void setPageSize(final int pageSize)
{
this.pageSize = pageSize;
}

public int getPageCount()
{
return pageCount;
}

public void setPageCount(final int pageCount)
{
this.pageCount = pageCount;
}

public int getPage()
{
return page;
}

public void setPage(final int page)
{
this.page = page;
}

public int getStart()
{
return start;
}

public void setStart(final int start)
{
this.start = start;
}

}

package common.web;

import javax.servlet.http.HttpServletRequest;

import org.apache.struts2.ServletActionContext;

import common.dao.Page;

public class WebPage extends Page
{
public final int DEFAULT_NAV_SIZE = 20; // 导航页数

private boolean center = true; //默认居中

private String className = "page_css"; //默认CSS

/**
* 构造方法
*
* @param nPageSize
*            每页记录数
* @param nPage
*            本页页号
*/
public WebPage(final int nPageSize, final int nPage, final String sPageURLParas)
{
super(nPageSize, nPage);
setPageURL(sPageURLParas);
}

/**
* 构造方法
*
* @param nPageSize
*            每页记录数
* @param nPage
*            本页页号
*/
public WebPage(final int nPageSize, final int nPage)
{
super(nPageSize, nPage);
setPageURL("");
}

/**
* 构造方法 ,默认每页20条记录
*
* @param nPage
*            本页页号
*/
public WebPage(final int nPage)
{
super(nPage);
setPageURL("");
}

private String pageURL; // 导航地址

private String pageNAV; // 导航表格

public void setPageURL(final String sPageURLPara)
{
//final HttpServletRequest request,
final HttpServletRequest request = ServletActionContext.getRequest();
if (sPageURLPara.length() > 0)
{
pageURL = "?" + sPageURLPara.substring(1) + "&";
}
else
{
pageURL = "?";
}
pageURL = request.getRequestURI() + pageURL + "page=";
pageNAV = null;
}

public String getPageNAV()
{
final int nPageNav = DEFAULT_NAV_SIZE; // 导航页数
final int nPage = page; // 当前页号
final int nPageMin = CalcMinPage(nPageNav); // 开始页号
final int nPageMax = CalcMaxPage(nPageNav); // 结束页号
final StringBuffer sPageNav = new StringBuffer(1024);
if (nPageMin < nPageMax)
{

sPageNav.append("<table class=\"" + className + "\"");
if (center)
{
//导航条居中 ,样式表
sPageNav.append(" align=\"center\">");
}
sPageNav.append("<tr>\r\n");
if (nPageMin != nPage)
{

sPageNav.append("<td><a href=\"");
sPageNav.append(pageURL + (nPage - 1));
sPageNav.append("\">上页</a></td>\r\n");
}
else
{
sPageNav.append("<td>上页</td>\r\n");
}
for (int i = nPageMin; i <= nPageMax; i++)
{
sPageNav.append("<td>");
if (i != nPage)
{
sPageNav.append("<a style='text-decoration: underline' href=\"");
sPageNav.append(pageURL + (i));
sPageNav.append("\">");
}
if (i != nPage)
{
sPageNav.append(i);
}
else
{
sPageNav.append("<b style='color:#ff7700'>" + (i) + "</b>");
}
if (i != nPage)
{
sPageNav.append("</a>");
}
sPageNav.append("</td>\r\n");
}

if (nPageMax != nPage)
{

sPageNav.append("<td><a style='text-decoration: underline' href=\"");
sPageNav.append(pageURL + (page + 1));
sPageNav.append("\">下页</a></td>\r\n");
}
else
{
sPageNav.append("<td>下页</td>\r\n");
}
sPageNav.append("</tr></table>\r\n");
}
pageNAV = sPageNav.toString();
return pageNAV;
}

public boolean isCenter()
{
return center;
}

public void setCenter(final boolean center)
{
this.center = center;
}

public String getClassName()
{
return className;
}

public void setClassName(final String className)
{
this.className = className;
}
}

package pic.dao;

import java.util.Iterator;
import java.util.List;
import java.util.Map;

import javax.annotation.Resource;

import org.hibernate.Criteria;
import org.hibernate.Query;
import org.hibernate.Session;
import org.hibernate.SessionFactory;
import org.hibernate.criterion.Projections;
import org.springframework.orm.hibernate3.support.HibernateDaoSupport;
import org.springframework.stereotype.Repository;

import common.dao.Page;

@Repository
public class HibernateUtil extends HibernateDaoSupport
{

/**
* 注入sessionFactory
*
* @param sessionFactory
*/
@Resource(name = "sessionFactory")
public void setFactory(final SessionFactory sessionFactory)
{
//HibernateDaoSupport上的方法,注入sessionFactory
setSessionFactory(sessionFactory);
}

/**
* 取得当前session
*
* @return
*/
public Session getCS()
{
return this.getSession();
//return this.getSessionFactory().getCurrentSession();
}

/**
* HQL分页查询
*
* @param page
*            分页对象,包含分页信息,如每页记录数,当前页码等
* @patam patam 参数集合 HQL如下:from User where expertname like :expertname
*        map.put("expertname", "%" + expertName + "%");
*        expertname是HQL中的:expertname
*
* @param hqlCount
*            计算总记录数的sql
* @param hql
*            查询的Sql
* @return List 结果集合
*/
@SuppressWarnings("unchecked")
public List findListPage(final Page page, final Map param, final String hqlCount, final String hql)
{
final Session session = this.getCS();
//查询总记录条数的Query
final Query query_count = session.createQuery(hqlCount);

//查询的Query
final Query query = session.createQuery(hql);
if (param != null)
{
//query.setProperties(param);
final Iterator it = param.keySet().iterator();
while (it.hasNext())
{
final Object key = it.next();
//两个Query查询条件相同
query_count.setParameter(key.toString(), param.get(key));
query.setParameter(key.toString(), param.get(key));
}
}
//总记录数
final int nCount = ((Long) query_count.iterate().next()).intValue();
//计算分页数据
page.init(nCount);
//从第N条开始
query.setFirstResult(page.getStart());
//取出X条
query.setMaxResults(page.getPageSize());
final List list = query.list();
return list;
}

/**
* Criteria 分页查询, 要事先设置好查询条件, 再把Criteria对象传进来
*
* @param page
*            分页对象
* @param criteria
*            Criteria对象,要事先设置好查询条件, 再把Criteria对象传进来 ,
*            如criteria.add(Restrictions.eq("name", "zl"))
*
* @return 结果集合
*/
@SuppressWarnings("unchecked")
public List findListPage(final Page page, final Criteria criteria)
{
// 获取根据条件分页查询的总行数 
final int rowCount = (Integer) criteria.setProjection(Projections.rowCount()).uniqueResult();
criteria.setProjection(null);
//计算分页数据
page.init(rowCount);
criteria.setFirstResult(page.getStart());
criteria.setMaxResults(page.getPageSize());
return criteria.list();
}

}

package junit_test.pic.dao;

import java.util.HashMap;
import java.util.List;
import java.util.Map;

import junit_test.base.JUnitBase_svc;

import org.hibernate.Criteria;
import org.hibernate.Session;
import org.hibernate.criterion.Restrictions;
import org.junit.BeforeClass;
import org.junit.Test;

import pic.dao.HibernateUtil;
import pic.dao.entity.Email;
import pic.svc.EmailManager;

import common.dao.Page;

/**
* 测试HibernateUtil 基类
*
* @author zl
*
*/
public class HibernateUtilTest extends JUnitBase_svc
{
static HibernateUtil hibernateUtil;

@BeforeClass
public static void setUpBeforeClass() throws Exception
{
hibernateUtil = (HibernateUtil) getBean("hibernateUtil");
}

/**
* 测试取得hibernateUtil bean
*/
@Test
public void testGetHibernateUtil()
{
assertNotNull(hibernateUtil);
}

@Test
public void add()
{
//先添加一些邮件
for (int i = 0; i < 7; i++)
{
final Email email = new Email();
email.setContent("内容2");
email.setIndex(2);
email.setQueueName("队列名称2");
email.setReceivers("Receivers2");
email.setSubject("Subject2");
email.setSum(20);
final EmailManager emailManagerImpl = (EmailManager) getBean("emailManagerImpl");
emailManagerImpl.add(email);
}
}

/**
* 测试分页方法
*/
@SuppressWarnings("unchecked")
@Test
public void testFindListPage()
{

//分页测试 , 第一页
final String where = " where content=:content ";
final String hqlCount = "select count(*) from Email" + where;
final String hql = "from Email" + where;

final Map<String, Object> param = new HashMap<String, Object>();
param.put("content", "内容2");

final List<Email> list = hibernateUtil.findListPage(new Page(), param, hqlCount, hql);
for (final Email e : list)
{
System.out.println(e.toString());
}

//测试 超出总页数
hibernateUtil.findListPage(new Page(10000), param, hqlCount, hql);

//测试 当前页码小于0
hibernateUtil.findListPage(new Page(-1), param, hqlCount, hql);
}

/**
* 测试分页方法
*/
@Test
public void testFindListPage2()
{
final Session session = getNewS();
final Criteria criteria = session.createCriteria(Email.class);
criteria.add(Restrictions.eq("content", "内容2"));
//criteria.add(Restrictions.like(propertyName, value))
final List<Email> list = hibernateUtil.findListPage(new Page(2), criteria);
for (final Email e : list)
{
System.out.println(e.toString());
}
}
}