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发表时间：2005-08-30
看了robbin和downpour的文章,感觉非常棒,我就拿来试试.
个人觉得DetachedCriteria的动态查询(QBC)还是优于HQL的,所以觉得采用QBC来进行查询.但是downpour的层次性好,而且把page分页类的初始化和操作分开,将页面对象化,那么涉及到页面的时候只要传一个page对象,至于内部page是如何的可以不用管了,又更好的封装性.但是从算法而言,两位牛人的应该是一样的. 所以我想把两个结合一下,利用downpour GG的层次结构,用QBC(DetachedCriteria)查询条件...前面的原封不动,只要在DAO实现这里修改一下就行了.但是具体实现有问题,我是个初学者,对这些东西的原理还不是很清楚. /*Created on 2005-7-15*/
package com.adt.dao.impl;
import java.util.List;
import org.flyware.util.page.Page;
import net.sf.hibernate.HibernateException;
import net.sf.hibernate.Query;
import com.adt.dao.UserDAO;
/**
* @author Joa
*/
public class UserDAOImpl extends BaseDAOHibernateImpl implements UserDAO {
/* (non-Javadoc);
* @see com.adt.dao.UserDAO#getUserByName(java.lang.String);
*/
public List getUserByName(String name); throws HibernateException {
String querySentence = "FROM user in class com.adt.po.User WHERE user.name=:name";
Query query = getSession();.createQuery(querySentence);;
query.setParameter("name", name);;
return query.list();;
}
/* (non-Javadoc);
* @see com.adt.dao.UserDAO#getUserCount();
*/
public int getUserCount(); throws HibernateException {
int count = 0;
String querySentence = "SELECT count(*); FROM user in class com.adt.po.User";
Query query = getSession();.createQuery(querySentence);;
count = ((Integer);query.iterate();.next(););.intValue();;
return count;
}
/* (non-Javadoc);
* @see com.adt.dao.UserDAO#getUserByPage(org.flyware.util.page.Page);
*/
public List getUserByPage(Page page); throws HibernateException {
String querySentence = "FROM user in class com.adt.po.User";
Query query = getSession();.createQuery(querySentence);;
query.setFirstResult(page.getBeginIndex(););
.setMaxResults(page.getEveryPage(););;
return query.list();;
}
}
下面是我写的一点,把上面的HQL转换成QBC..很明显有问题,希望懂的达人帮忙给我看看 public List getStudentByPage(Page page); throws HibernateException {
//HQL实现
String querySentence = "FROM user in class com.adt.po.User";
Query query = getSession();.createQuery(querySentence);;
//DetachedCriteria实现
//处理JSF参数
studentId = FacesUtils.getRequestParameter("query:stuId");;
studentName = FacesUtils.getRequestParameter("query:stuName");;
studentSex = FacesUtils.getRequestParameter("query:sex");;
studentDegree = FacesUtils.getRequestParameter("query:degree");;
studentProvince = FacesUtils.getRequestParameter("query:province");;
this.logger.debug("------------studentName----> "+ studentId);;
this.logger.debug("------------studentName----> "+ studentName);;
this.logger.debug("------------studentName----> "+ studentSex);;
this.logger.debug("------------studentName----> "+ studentDegree);;
this.logger.debug("------------studentName----> "+ studentProvince);;
//设置页面
int pageSize = 10;
int startIndex = 0;
//构造DetachedCriteria
DetachedCriteria detachedCriteria = DetachedCriteria.forClass(Student.class);;
detachedCriteria.add(Restrictions.eq("stuName", studentName););;
Criteria criteria = null;//这里不知道怎么写,肯定不是这样写的
criteria.setFirstResult(page.getBeginIndex(););
.setMaxResults(page.getEveryPage(););;
return criteria.list();;
}
Criteria criteria = null;//这里该怎么写???在看到的资料都要涉及到session...DetachedCriteria好像没setFirstResult和setMaxResults..如何讲Criteria和DetachedCriteria联系起来,还是有其他的方法写这个??? |
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发表时间：2005-08-30
我也用了robbin的方法来做,直接QBC查询
在bean里面的action里实现分页 public String queryAction();{
this.logger.debug("get into queryAction!!!!!!!!!");;
try{
//处理JSF参数
studentId = FacesUtils.getRequestParameter("query:stuId");;
studentName = FacesUtils.getRequestParameter("query:stuName");;
studentSex = FacesUtils.getRequestParameter("query:sex");;
studentDegree = FacesUtils.getRequestParameter("query:degree");;
studentProvince = FacesUtils.getRequestParameter("query:province");;
this.logger.debug("------------studentName----> "+ studentId);;
this.logger.debug("------------studentName----> "+ studentName);;
this.logger.debug("------------studentName----> "+ studentSex);;
this.logger.debug("------------studentName----> "+ studentDegree);;
this.logger.debug("------------studentName----> "+ studentProvince);;
//设置页面
int pageSize = 10;
int startIndex = 0;
//构造DetachedCriteria
DetachedCriteria detachedCriteria = DetachedCriteria.forClass(Student.class);;
detachedCriteria.add(Restrictions.eq("stuName", studentName););;
// //直接查询
// PaginationSupport ps = AbstractManager.findPageByCriteria(DetachedCriteria
// .forClass(Student.class);, PageUtil.getEveryPage(pageSize);, PageUtil.getBeginIndex(startIndex););;
PaginationSupport ps = AbstractManager.findPageByCriteria(detachedCriteria, pageSize, startIndex);;
ps.getItems();; //得到已分页好的结果集
ps.getIndexes();; //得到分页索引的数组
ps.getTotalCount();; //得到总结果数
ps.getStartIndex();; //当前分页索引
ps.getNextIndex();; //下一页索引
ps.getPreviousIndex();; //上一页索引
//调用service
List listStu = this.serviceLocator.getStudentService();.getStudents(detachedCriteria);;
//List listStu = this.serviceLocator.getStudentService();.findStudent(stuId,stuName);;
// this.logger.debug("listStu.size(); = "+ listStu.size(); );;
//处理返回的纪录集
for (int i=0; i<listStu.size();; i++); {
Student stu = (Student);listStu.get(i);;
StudentBean studentBean = StudentBuilder.createStudentBean(stu);;
studentBean.setServiceLocator(this.serviceLocator);;
this.studentBeans.add(studentBean);;
this.logger.debug("listStu==i= "+i );;
}
}catch (AppException ce); {
String msg = "Could not retrieve Students " ;
this.logger.debug(msg, ce);;
throw new FacesException(msg, ce);;
}
return "QUERY_SUCCESS" ;
}
PaginationSupport ps = AbstractManager.findPageByCriteria(detachedCriteria, pageSize, startIndex);;这里说返回类型不对,static和non-static..应该是返回的类型不对吧... 这个有问题吗??有什么不规范和不对的地方吗???? |
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发表时间：2005-09-19
/**
* 分页信息接口
*/
public interface Page <E>extends Serializable,Iterable
{
/**
* 是否是首页（第一页），第一页页码为1
*
* @return 首页标识
*/
public boolean isFirstPage();;
/**
* 是否是最后一页
*
* @return 末页标识
*/
public boolean isLastPage();;
/**
* 是否有下一页
*
* @return 下一页标识
*/
public boolean hasNextPage();;
/**
* 是否有上一页
*
* @return 上一页标识
*/
public boolean hasPreviousPage();;
/**
* 获取最后一页页码，也就是总页数
*
* @return 最后一页页码
*/
public int getLastPageNumber();;
/**
* 当前页包含的数据，不同的情况可能返回的数据类型不一样，如List，RowSet等，请参考具体的实现
*
* @return 当前页数据源
*/
public E getThisPageElements();;
/**
* 总的数据条目数量，0表示没有数据
*
* @return 总数量
*/
public int getTotalNumberOfElements();;
/**
* 获取当前页的首条数据的行编码
*
* @return 当前页的首条数据的行编码
*/
public int getThisPageFirstElementNumber();;
/**
* 获取当前页的末条数据的行编码
*
* @return 当前页的末条数据的行编码
*/
public int getThisPageLastElementNumber();;
/**
* 获取下一页编码
*
* @return 下一页编码
*/
public int getNextPageNumber();;
/**
* 获取上一页编码
*
* @return 上一页编码
*/
public int getPreviousPageNumber();;
/**
* 每一页显示的条目数
*
* @return 每一页显示的条目数
*/
public int getPageSize();;
/**
* 当前页的页码
*
* @return 当前页的页码
*/
public int getThisPageNumber();;
}
BasePage用于其它的page子类继承
/**
* 高层的Page接口实现
*
* @author QIU
*/
public class BasePage<E> implements Page {
protected E elements;
protected int pageSize;
protected int pageNumber;
protected int totalElements = 0;
public BasePage(int pageNumber, int pageSize, int totalElements); {
this.pageNumber = pageNumber;
this.pageSize = pageSize;
this.totalElements = totalElements;
recomputePageNumber();;
}
public BasePage(int pageNumber, int pageSize); {
this.pageNumber = pageNumber;
this.pageSize = pageSize;
}
/**
* 重新计算当前页的号码
*/
protected void recomputePageNumber(); {
if (Integer.MAX_VALUE == this.pageNumber
|| this.pageNumber > getLastPageNumber();); { //last page
this.pageNumber = getLastPageNumber();;
}
}
public boolean isFirstPage(); {
return getThisPageNumber(); == 1;
}
public boolean isLastPage(); {
return getThisPageNumber(); >= getLastPageNumber();;
}
public boolean hasNextPage(); {
return getLastPageNumber(); > getThisPageNumber();;
}
public boolean hasPreviousPage(); {
return getThisPageNumber(); > 1;
}
public int getLastPageNumber(); {
return totalElements % this.pageSize == 0 ?
totalElements/ this.pageSize
: totalElements / this.pageSize + 1;
}
public E getThisPageElements(); {
return elements;
}
public int getTotalNumberOfElements(); {
return totalElements;
}
public int getThisPageFirstElementNumber(); {
return (getThisPageNumber(); - 1); * getPageSize(); + 1;
}
public int getThisPageLastElementNumber(); {
int fullPage = getThisPageFirstElementNumber(); + getPageSize(); - 1;
return getTotalNumberOfElements(); < fullPage ? getTotalNumberOfElements(); : fullPage;
}
public int getNextPageNumber(); {
return getThisPageNumber(); + 1;
}
public int getPreviousPageNumber(); {
return getThisPageNumber(); - 1;
}
public int getPageSize(); {
return pageSize;
}
public int getThisPageNumber(); {
return pageNumber;
}
/**
* 实现Iterable遍历接口
* @return 等价((Iterable);getThisPageElements(););.iterator();
* @throws UnsupportedOperationException
* 当getThisPageElements();不是Iterable接口
* @See java.lang.Iterable
*/
public Iterator iterator(); {
if(getThisPageElements(); instanceof Iterable); {
return ((Iterable);getThisPageElements(););.iterator();;
}
else {
throw new UnsupportedOperationException("iterator(); method is unsupported");;
}
}
}
现在我们的HibernatePage实现类,只需简单的执行一下查询就行了
/**
* Hibernate分页信息
* @see BasePage
*/
public class HibernatePage extends BasePage implements Page
{
/**
* 构建HibernatePage对象，完成Hibernate的Query数据的分页处理
*
* @param query Hibernate的Query对象
* @param pageNumber 当前页编码，从1开始，如果传的值为Integer.MAX_VALUE表示获取最后一页。
* 如果你不知道最后一页编码，传Integer.MAX_VALUE即可。如果当前页超过总页数，也表示最后一页。
* 这两种情况将重新更改当前页的页码，为最后一页编码。
* @param pageSize 每一页显示的条目数
*/
public HibernatePage(Query query, int pageNumber, int pageSize);
{
super(pageNumber,pageSize);;
try
{
ScrollableResults scrollableResults = query.scroll();;
//get the total elements number
scrollableResults.last();;
this.totalElements = scrollableResults.getRowNumber();;
recomputePageNumber();;
elements = query.setFirstResult((this.pageNumber - 1); * this.pageSize);.setMaxResults(this.pageSize + 1);.list();;
} catch (HibernateException e);
{
throw new RuntimeException(e);;
}
}
/**
* 构建HibernatePage对象，完成Hibernate的Query数据的分页处理
*
* @param selectQuery Hibernate的查询Query对象
* @param countQuery Hibernate的查询总数据行数的Query对象
* @param pageNumber 当前页编码，从1开始，如果传的值为Integer.MAX_VALUE表示获取最后一页。
* 如果你不知道最后一页编码，传Integer.MAX_VALUE即可。如果当前页超过总页数，也表示最后一页。
* 这两种情况将重新更改当前页的页码，为最后一页编码。
* @param pageSize 每一页显示的条目数
*/
public HibernatePage(Query selectQuery, Query countQuery,int pageNumber, int pageSize);
{
super(pageNumber,pageSize);;
try
{
//得到总记录数
this.totalElements = ((Integer);countQuery.uniqueResult(););.intValue();;
recomputePageNumber();;
elements = selectQuery
.setFirstResult((this.pageNumber - 1); * this.pageSize);
.setMaxResults(this.pageSize + 1);
.list();;
} catch (HibernateException e);
{
throw new RuntimeException(e);;
}
}
}
EJB3.0的Page接口实现EJBPage
/**
* EJB分页信息
* @author QIU
* @see BasePage
*/
public class EJBPage extends BasePage {
public EJBPage(Query selectQuery,Query countQuery,int pageNumber,int pageSize); {
super(pageNumber,pageSize);;
this.totalElements = (Integer);countQuery.getSingleResult();;
recomputePageNumber();;
this.elements = selectQuery
.setFirstResult((this.pageNumber - 1); * this.pageSize);
.setMaxResults(this.pageSize + 1);
.getResultList();;
}
}
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发表时间：2005-09-19
JDBCPage
/** * Jdbc分页信息，需要Jdk 1.5的支持 * @see Page * @see BasePage */ public class JdbcPage extends BasePage //implements Page { // private CachedRowSet elements; // private int pageSize; // private int pageNumber; // private int totalElements = 0; /** * 构建JdbcPage对象，完成JDBC的ResultSet分页处理 * * @param rs ResultSet对象，ResultSet必须是可滚动的数据集，可以通过以下的Statement执行查询。 * Statement stmt = conn.createStatement( ResultSet.TYPE_SCROLL_INSENSITIVE, ResultSet.CONCUR_READ_ONLY); * @param pageNumber 当前页编码，从1开始，如果传的值为Integer.MAX_VALUE表示获取最后一页。 * 如果你不知道最后一页编码，传Integer.MAX_VALUE即可。如果当前页超过总页数，也表示最后一页。 * 这两种情况将重新更改当前页的页码，为最后一页编码。 * @param pageSize 每一页显示的条目数 */ public JdbcPage(ResultSet rs, int pageNumber, int pageSize) { super(pageNumber,pageSize); try { //get the total elements number rs.last(); totalElements = rs.getRow(); // if (this.pageNumber == Integer.MAX_VALUE || this.pageNumber > getLastPageNumber()) // { // this.pageNumber = getLastPageNumber(); // } recomputePageNumber(); CachedRowSet elements = new CachedRowSetImpl(); elements.setMaxRows(this.pageSize); elements.setPageSize(this.pageSize); elements.populate(rs, (this.pageNumber - 1) * this.pageSize); this.elements = elements; } catch (SQLException e) { throw new RuntimeException(e); } } /** * 构建JdbcPage对象，完成JDBC的ResultSet分页处理 * * @param rs ResultSet对象，ResultSet必须是可滚动的数据集，可以通过以下的Statement执行查询。 * Statement stmt = conn.createStatement( ResultSet.TYPE_SCROLL_INSENSITIVE, ResultSet.CONCUR_READ_ONLY); * @param pageNumber 当前页编码，从1开始，如果传的值为Integer.MAX_VALUE表示获取最后一页。 * 如果你不知道最后一页编码，传Integer.MAX_VALUE即可。如果当前页超过总页数，也表示最后一页。 * 这两种情况将重新更改当前页的页码，为最后一页编码。 * @param pageSize 每一页显示的条目数 */ public JdbcPage(ResultSet rs,BusinessObjectCreator creator, int pageNumber, int pageSize) { super(pageNumber,pageSize); try { //get the total elements number rs.last(); totalElements = rs.getRow(); recomputePageNumber(); this.elements = populateIntoList(rs,creator,pageNumber,pageSize); } catch (SQLException e){ throw new RuntimeException(e); } } private static List populateIntoList(ResultSet rs, BusinessObjectCreator factory, int pageNumber, int pageSize) throws SQLException { List result = new ArrayList(); //移动到页码的第一条记录,忽略第一页 if(pageNumber>1){ rs.absolute(((pageNumber-1)*pageSize)); } for(int i=0;i<pageSize;i++){ if(rs.next()){ result.add(factory.getBusinessObject(rs)); } else{ if(i==0){ //没有记录的情况 return null; } break; } } return result; } } BusinessObjectCreator接口
/**
* 业务对象创建接口,用于JDBCPage创建对象方法回调
* @author QIU
*
*/
public interface BusinessObjectCreator {
public Object getBusinessObject(ResultSet rs);;
}
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发表时间：2005-09-20
/**
* Hibernate使用Criteria分页信息
* @author QIU
*
*/
public class CriteriaPage extends BasePage{
public CriteriaPage(Criteria criteria,int pageNumber, int pageSize); {
super(pageNumber,pageSize);;
//得到总记录数
ScrollableResults scrollableResults = criteria.scroll();;
scrollableResults.last();;
this.totalElements = scrollableResults.getRowNumber();;
recomputePageNumber();;
elements = criteria
.setFirstResult((this.pageNumber - 1); * this.pageSize);
.setMaxResults(this.pageSize + 1);.list();;
}
}
重贴JdbcPage
/**
* Jdbc分页信息，需要Jdk 1.5的支持
* @see Page
* @see BasePage
*/
public class JdbcPage extends BasePage //implements Page
{
// private CachedRowSet elements;
// private int pageSize;
// private int pageNumber;
// private int totalElements = 0;
/**
* 构建JdbcPage对象，完成JDBC的ResultSet分页处理
*
* @param rs ResultSet对象，ResultSet必须是可滚动的数据集，可以通过以下的Statement执行查询。
* Statement stmt = conn.createStatement( ResultSet.TYPE_SCROLL_INSENSITIVE, ResultSet.CONCUR_READ_ONLY);;
* @param pageNumber 当前页编码，从1开始，如果传的值为Integer.MAX_VALUE表示获取最后一页。
* 如果你不知道最后一页编码，传Integer.MAX_VALUE即可。如果当前页超过总页数，也表示最后一页。
* 这两种情况将重新更改当前页的页码，为最后一页编码。
* @param pageSize 每一页显示的条目数
*/
public JdbcPage(ResultSet rs, int pageNumber, int pageSize);
{
super(pageNumber,pageSize);;
try
{
//get the total elements number
rs.last();;
totalElements = rs.getRow();;
// if (this.pageNumber == Integer.MAX_VALUE || this.pageNumber > getLastPageNumber(););
// {
// this.pageNumber = getLastPageNumber();;
// }
recomputePageNumber();;
CachedRowSet elements = new CachedRowSetImpl();;
elements.setMaxRows(this.pageSize);;
elements.setPageSize(this.pageSize);;
elements.populate(rs, (this.pageNumber - 1); * this.pageSize);;
this.elements = elements;
} catch (SQLException e);
{
throw new RuntimeException(e);;
}
}
/**
* 构建JdbcPage对象，完成JDBC的ResultSet分页处理
*
* @param rs ResultSet对象，ResultSet必须是可滚动的数据集，可以通过以下的Statement执行查询。
* Statement stmt = conn.createStatement( ResultSet.TYPE_SCROLL_INSENSITIVE, ResultSet.CONCUR_READ_ONLY);;
* @param pageNumber 当前页编码，从1开始，如果传的值为Integer.MAX_VALUE表示获取最后一页。
* 如果你不知道最后一页编码，传Integer.MAX_VALUE即可。如果当前页超过总页数，也表示最后一页。
* 这两种情况将重新更改当前页的页码，为最后一页编码。
* @param pageSize 每一页显示的条目数
*/
public JdbcPage(ResultSet rs,BusinessObjectCreator creator, int pageNumber, int pageSize);
{
super(pageNumber,pageSize);;
try
{
//get the total elements number
rs.last();;
totalElements = rs.getRow();;
recomputePageNumber();;
this.elements = populateIntoList(rs,creator,pageNumber,pageSize);;
} catch (SQLException e);{
throw new RuntimeException(e);;
}
}
private static List populateIntoList(ResultSet rs, BusinessObjectCreator factory, int pageNumber, int pageSize); throws SQLException {
List result = new ArrayList();;
//移动到页码的第一条记录,忽略第一页
if(pageNumber>1);{
rs.absolute(((pageNumber-1);*pageSize););;
}
for(int i=0;i<pageSize;i++);{
if(rs.next(););{
result.add(factory.getBusinessObject(rs););;
} else{
if(i==0);{ //没有记录的情况
return null;
}
break;
}
}
return result;
}
}
/**
* 业务对象创建接口,用于JDBCPage创建对象方法回调
* @author QIU
*
*/
public interface BusinessObjectCreator {
public Object getBusinessObject(ResultSet rs);;
}
其它的Page接口实现,我们只需简单的继承BasePage,轻松的就可以增加对Page的实现.Page接口详细可以查看Hibernate官网上的描述 |
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发表时间：2005-09-21
用
ScrollableResults scrollableResults = query.scroll(); //get the total elements number scrollableResults.last(); this.totalElementsCount = scrollableResults.getRowNumber() + 1; 我使用oracle9i + oracle10 jdbc driver, 在数据量大的情况下，会有outofmemery exception的 |
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发表时间：2005-10-18
今天试了一下robbin的分页方法，发现一个问题
方法代码： public PaginationSupport findPageByCriteria(final DetachedCriteria detachedCriteria, final int pageSize,
final int startIndex); {
return (PaginationSupport); getHibernateTemplate();.execute(new HibernateCallback(); {
public Object doInHibernate(Session session); throws HibernateException {
Criteria criteria = detachedCriteria.getExecutableCriteria(session);;
int totalCount = ((Integer); criteria.setProjection(Projections.rowCount(););.uniqueResult(););.intValue();;
[b]criteria.setProjection(null);;[/b]
List items = criteria.setFirstResult(startIndex);.setMaxResults(pageSize);.list();;
PaginationSupport ps = new PaginationSupport(items, totalCount, pageSize, startIndex);;
return ps;
}
}, true);;
}
调用代码：
DetachedCriteria dc=DetachedCriteria .forClass(Cat.class);;
dc.createAlias("mate","mt");
.add(Property.forName("mt.name");.like("miaomiao",MatchMode.ANYWHERE););;
PaginationSupport ps = findPageByCriteria(dc,20,0);;
List list = ps.getItems();;
[b]Object[] objects = Object[] list.get(0);;[/b]
发现返回的List里面放的不是我本来想要的Cat, 而是Object[]. |
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发表时间：2005-10-18
经过测试，看来问题出在 criteria.setProjection(null); 上。
|
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发表时间：2005-12-23
有没有解决方案啊？
|
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发表时间：2005-12-23
goldapple 写道 有没有解决方案啊？
package com.skyon.cams.util;
import java.lang.reflect.Field;
import java.sql.SQLException;
import java.util.ArrayList;
import java.util.List;
import org.apache.commons.lang.StringUtils;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.hibernate.Criteria;
import org.hibernate.HibernateException;
import org.hibernate.Session;
import org.hibernate.criterion.CriteriaSpecification;
import org.hibernate.criterion.DetachedCriteria;
import org.hibernate.criterion.Projection;
import org.hibernate.criterion.Projections;
import org.hibernate.impl.CriteriaImpl;
import org.hibernate.impl.CriteriaImpl.OrderEntry;
import org.springframework.dao.DataAccessException;
import org.springframework.orm.hibernate3.HibernateCallback;
import org.springframework.orm.hibernate3.HibernateTemplate;
import org.springframework.util.Assert;
import com.skyon.framework.core.SkyonException;
import com.skyon.framework.dao.PaginationSupport;
/**
* 一些常用的 Hibernate 方法, 注意, 一些方法可能只适用于 Hibernate3.0.5 !!!
* @see org.springframework.orm.hibernate3.HibernateTemplate
* @since 2005-9-13
* @author 王政
* @version $Id: HibernateUtils.java,v 1.4 2005/09/19 01:00:28 wangzheng Exp $
*/
public abstract class HibernateUtils {
private static Log logger = LogFactory.getLog(HibernateUtils.class);;
public static final String CRITERIA_ASSERT_ERROR_MESSAGE = " 's type is not " + CriteriaImpl.class + ", please make sure you are using Hibernate3.0.5!!! ";
/**
* 将 Criteria 加上分页条件并输出结果
* @param criteria the criteria
* @param offset the offset
* @param maxPageItems the maxPageItems
* @return the result list
*/
public static List getPageResult(Criteria criteria, int offset, int maxPageItems); throws HibernateException {
criteria.setFirstResult(offset);;
criteria.setMaxResults(maxPageItems);;
return criteria.list();;
}
/**
* 根据 DetachedCriteria 得 到 分页结果, 运行期间会根据 criteria 自动运算总行数, 注意如果 criteria 中 set 了 Projection, 则返回结果 List 中为 Projection 指定类型
* @param hibernateTemplate the hibernateTemplate
* @param criteria the criteria
* @param firstResult the first result row number
* @param maxResults the max result
* @return the pagination support
* @throws org.springframework.dao.DataAccessException in case of Hibernate errors
*/
public static PaginationSupport findByCriteria(HibernateTemplate hibernateTemplate, final DetachedCriteria criteria, final int firstResult, final int maxResults);
throws DataAccessException {
return (PaginationSupport); hibernateTemplate.execute(new HibernateCallback(); {
public Object doInHibernate(Session session); throws HibernateException, SQLException {
Criteria executableCriteria = criteria.getExecutableCriteria(session);;
// Get the orginal orderEntries
OrderEntry[] orderEntries = HibernateUtils.getOrders(executableCriteria);;
// Remove the orders
executableCriteria = HibernateUtils.removeOrders(executableCriteria);;
// get the original projection
Projection projection = HibernateUtils.getProjection(executableCriteria);;
int totalCount = ((Integer); executableCriteria.setProjection(Projections.rowCount(););.uniqueResult(););.intValue();;
executableCriteria.setProjection(projection);;
if (projection == null); {
// Set the ResultTransformer to get the same object structure with hql
executableCriteria.setResultTransformer(CriteriaSpecification.ROOT_ENTITY);;
}
// Add the orginal orderEntries
executableCriteria = HibernateUtils.addOrders(executableCriteria, orderEntries);;
// Now, the Projection and the orderEntries have been resumed
List items = HibernateUtils.getPageResult(executableCriteria, firstResult, maxResults);;
return new PaginationSupport(items, totalCount, firstResult, maxResults);;
}
}, true);;
}
/**
* 根据 hql 得 到 总行数
* @param hibernateTemplate
* @param queryString hql
* @param isNamedQuery 是否是 named query
* @param paramNames 如果是 named query, 为 named query 中的参数名称, 否则无意义
* @param paramValues 参数值
* @return 满足条件的总行数
* @throws IllegalArgumentException if queryString is blank
* @throws org.springframework.dao.DataAccessException in case of Hibernate errors
*/
public static int getTotalCount(HibernateTemplate hibernateTemplate, String queryString, boolean isNamedQuery, String[] paramNames, Object[] paramValues);
throws IllegalArgumentException, DataAccessException {
if (StringUtils.isBlank(queryString);); {
throw new IllegalArgumentException(" queryString can't be blank ");;
}
String countQueryString = " select count (*); " + JdbcUtils.removeSelect(JdbcUtils.removeOrders(queryString););;
List countList;
if (isNamedQuery); {
countList = hibernateTemplate.findByNamedParam(countQueryString, paramNames, paramValues);;
} else {
countList = hibernateTemplate.find(countQueryString, paramValues);;
}
return ((Integer); countList.get(0););.intValue();;
}
/**
* 从 criteria 中取得 {@link Projection}, 接口中没有公开此方法, 因此从 {@link CriteriaImpl} 中取得
* @see CriteriaImpl#getProjection();
* @param criteria the criteria
* @return the Projection
*/
public static Projection getProjection(Criteria criteria); {
assertType(criteria);;
CriteriaImpl impl = (CriteriaImpl); criteria;
return impl.getProjection();;
}
private static void assertType(Criteria criteria); {
Assert.notNull(criteria, " criteria is required. ");;
String message = criteria + CRITERIA_ASSERT_ERROR_MESSAGE;
if (! CriteriaImpl.class.isInstance(criteria);); {
if (logger.isDebugEnabled();); {
logger.debug(message);;
}
throw new SkyonException(message);;
}
}
/**
* 得到 criteria 中的 OrderEntry[]
* @param criteria the criteria
* @return the OrderEntry[]
*/
public static OrderEntry[] getOrders(Criteria criteria); {
assertType(criteria);;
CriteriaImpl impl = (CriteriaImpl); criteria;
Field field = getOrderEntriesField(criteria);;
try {
return (OrderEntry[]); ((List); field.get(impl););.toArray(new OrderEntry[0]);;
} catch (Exception e); {
logAndThrowException(criteria, e);;
throw new InternalError(" Runtime Exception impossibility can't throw ");;
}
}
/**
* 移除 criteria 中的 OrderEntry[]
* @param criteria the criteria
* @return the criteria after removed OrderEntry[]
*/
public static Criteria removeOrders(Criteria criteria); {
assertType(criteria);;
CriteriaImpl impl = (CriteriaImpl); criteria;
try {
Field field = getOrderEntriesField(criteria);;
field.set(impl, new ArrayList(););;
return impl;
} catch (Exception e); {
logAndThrowException(criteria, e);;
throw new InternalError(" Runtime Exception impossibility can't throw ");;
}
}
/**
* 为 criteria 增加 OrderEntry[]
* @param criteria the criteria
* @param orderEntries the OrderEntry[]
* @return the criteria after add OrderEntry[]
*/
public static Criteria addOrders(Criteria criteria, OrderEntry[] orderEntries); {
assertType(criteria);;
CriteriaImpl impl = (CriteriaImpl); criteria;
try {
Field field = getOrderEntriesField(criteria);;
for (int i = 0; i < orderEntries.length; i++); {
List innerOrderEntries = (List); field.get(criteria);;
innerOrderEntries.add(orderEntries[i]);;
}
return impl;
} catch (Exception e); {
logAndThrowException(criteria, e);;
throw new InternalError(" Runtime Exception impossibility can't throw ");;
}
}
private static void logAndThrowException(Criteria criteria, Exception e); {
String message = criteria + CRITERIA_ASSERT_ERROR_MESSAGE;
if (logger.isDebugEnabled();); {
logger.debug(message, e);;
}
throw new SkyonException(message, e);;
}
private static Field getOrderEntriesField(Criteria criteria); {
Assert.notNull(criteria, " criteria is requried. " );;
try {
Field field = CriteriaImpl.class.getDeclaredField("orderEntries");;
field.setAccessible(true);;
return field;
} catch (Exception e); {
logAndThrowException(criteria, e);;
throw new InternalError();;
}
}
}
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