Matrix排名:1340
排名变化: --
用户等级:3
总发贴数:56
总积分(Karma):273
参与分(经验):262
专家分(威望):40
可用分(财富):100
类型:普通用户
注册:2005-10-19
进入XXYMJJ的部落格
|
|
上个星期偶然的一次机会，帮别人忙做一个Hibernate得东西，正好自己也有兴趣学习学习(^_^)，对Hibernate基础掌握之后，于是乎自然而然想到了Paging问题。当时Google以下，大家都与Hibernate Paging 原理都转贴了不少，但是真正结合起来的例子然而很少(几乎没有)。那天在论坛看到一个兄弟求一个Hibernate+Struts实现分页得例子。于是昨天下午4点-6点开始着手（下班回家有天下足球阿！），后来晚上睡觉都在向这个问题（失眠才想的，不是因为想而失眠 ~郁闷）。今天上午来了看了几十封垃圾邮件后，终于作了出来（由不足的地方情大家指出）。在此鸣谢“Norther ”兄弟对我HQL的支持（才开始学哈，多谢好心人啊）。废话少说，开始写：
前言，必读
1：由于长促写的，难免有不周到或者还有格式上面凌乱的问题。
2：对于Page function进行了一定的封装。用户只需要在PageBean 里面设置以下pageRecorders （每页显示条数据），然后在自己的Action里面组装自己需要的query就可以了。
3：对于Hibernate没有进行深入研究（时间有限），所以采取了每次翻页都采用一次查询。第一次显示的时候采用了两次查询（第一次是查询Hibernate.xml里面设定的一次查询长度的所有纪录，由此推算出总数据数，总页数等等，然后赋予第一页的起始数和第一页的终止数，由query.list(); 得出第一页的数据，这里可能会有更好的改进，希望大家指点。后面得翻页主要是得到第N页的起始数和第N页的终止数）
4: 在此鸣谢各位兄弟的支持,
正文：
关于Hibernate得基本配置什么的就不多说了。现在就只是写上Paging相关的代码：
1:
PageBean.java
/*
* Created on 2006-3-21
*
* To change the template for this generated file go to
* Window>Preferences>Java>Code Generation>Code and Comments
*/
package com.ibm.hibernate.beans;
import java.util.Iterator;
import java.util.List;
import javax.servlet.http.HttpServletRequest;
import net.sf.hibernate.HibernateException;
import net.sf.hibernate.Query;
import net.sf.hibernate.Session;
import net.sf.hibernate.SessionFactory;
import net.sf.hibernate.Transaction;
/**
* @author Johnny //PS: My English Name
*
* To change the template for this generated type comment go to
* Window>Preferences>Java>Code Generation>Code and Comments
*/
public class PageBean {
// public static final String HQL_DEMO_BYNAME =
// "from com.ibm.hibernate.beans.Demo as e where e.name=:tempName";
// public static final String HQL_DEMO_BYALL =
// "from com.ibm.hibernate.beans.Demo as e ";
int currentPage = 1; //当前页
public int totalPages = 0; //总页数
int pageRecorders = 5; //每页5条数据
int totalRows = 0; //总数据数
int pageStartRow = 0; //每页的起始数
int pageEndRow = 0; //每页显示数据的终止数
boolean hasNextPage = false; //是否有下一页
boolean hasPreviousPage = false; //是否有前一页
List list;
private Demo demo;
Iterator it;
static PageBean pb;
public PageBean() {
}
public PageBean(List list) {
this.list = list;
totalRows = list.size();
it = list.iterator();
hasPreviousPage = false;
currentPage = 1;
if ((totalRows % pageRecorders) == 0) {
totalPages = totalRows / pageRecorders;
} else {
totalPages = totalRows / pageRecorders + 1;
}
if (currentPage >= totalPages) {
hasNextPage = false;
} else {
hasNextPage = true;
}
if (totalRows < pageRecorders) {
this.pageStartRow = 0;
this.pageEndRow = totalRows;
} else {
this.pageStartRow = 0;
this.pageEndRow = pageRecorders;
}
}
/**
* @return Returns the currentPage.
*/
public String getCurrentPage() {
return this.toString(currentPage);
}
/**
* @param currentPage The currentPage to set.
*/
public void setCurrentPage(int currentPage) {
this.currentPage = currentPage;
}
/**
* @return Returns the pageRecorders.
*/
public int getPageRecorders() {
return pageRecorders;
}
/**
* @param pageRecorders The pageRecorders to set.
*/
public void setPageRecorders(int pageRecorders) {
this.pageRecorders = pageRecorders;
}
/**
* @return Returns the pageEndRow.
*/
public int getPageEndRow() {
return pageEndRow;
}
/**
* @return Returns the pageStartRow.
*/
public int getPageStartRow() {
return pageStartRow;
}
/**
* @return Returns the totalPages.
*/
public String getTotalPages() {
return this.toString(totalPages);
}
/**
* @return Returns the totalRows.
*/
public String getTotalRows() {
return this.toString(totalRows);
}
/**
* @return Returns the hasNextPage.
*/
public boolean isHasNextPage() {
return hasNextPage;
}
/**
* @param hasNextPage The hasNextPage to set.
*/
public void setHasNextPage(boolean hasNextPage) {
this.hasNextPage = hasNextPage;
}
/**
* @return Returns the hasPreviousPage.
*/
public boolean isHasPreviousPage() {
return hasPreviousPage;
}
/**
* @param hasPreviousPage The hasPreviousPage to set.
*/
public void setHasPreviousPage(boolean hasPreviousPage) {
this.hasPreviousPage = hasPreviousPage;
}
public void getNextPage() {
currentPage = currentPage + 1;
System.out.println("PageBean.getNextPage()正在执行；");
System.out.println("参数currentPage=" + currentPage);
if ((currentPage - 1) > 0) {
hasPreviousPage = true;
} else {
hasPreviousPage = false;
}
if (currentPage >= totalPages) {
hasNextPage = false;
} else {
hasNextPage = true;
}
System.out.println("参数hasNextPage=" + hasNextPage);
if (currentPage * pageRecorders < totalRows) { //判断是否为最后一页
pageEndRow = currentPage * pageRecorders;
pageStartRow = pageEndRow - pageRecorders;
} else {
pageEndRow = totalRows;
pageStartRow = pageRecorders * (totalPages - 1);
}
System.out.println("参数pageStartRow=" + pageStartRow);
System.out.println("参数pageEndRow=" + pageEndRow);
// Demo[] Demos = getDemos();
this.description();
}
public void getPreviouspage() {
currentPage = currentPage - 1;
if (currentPage == 0) {
currentPage = 1;
}
if (currentPage >= totalPages) {
hasNextPage = false;
} else {
hasNextPage = true;
}
if ((currentPage - 1) > 0) {
hasPreviousPage = true;
} else {
hasPreviousPage = false;
}
if (currentPage * pageRecorders < totalRows) { //判断是否为最后一页
pageEndRow = currentPage * pageRecorders;
pageStartRow = pageEndRow - pageRecorders;
} else {
pageEndRow = totalRows;
pageStartRow = pageRecorders * (totalPages - 1);
}
System.out.println("参数pageStartRow=" + pageStartRow);
System.out.println("参数pageEndRow=" + pageEndRow);
this.description();
}
public String toString(int temp) {
String str = Integer.toString(temp);
return str;
}
public void description() {
String description =
"共有数据数:"
+ this.getTotalRows()
+ "共有页数: "
+ this.getTotalPages()
+ "当前页数为:"
+ this.getCurrentPage()
+ " 是否有前一页: "
+ this.isHasPreviousPage()
+ " 是否有下一页:"
+ this.isHasNextPage()
+ " 开始行数:"
+ this.getPageStartRow()
+ " 终止行数:"
+ this.getPageEndRow();
System.out.println(description);
}
/**
* @return
*/
public Demo getDemo() {
return demo;
}
/**
* @param demo
*/
public void setDemo(Demo demo) {
this.demo = demo;
}
/**
* @return
*/
public List getList() {
return list;
}
/**
* @param list
*/
public void setList(List list) {
this.list = list;
}
/**
*
*/
public PageBean pagingFirsttime(
SessionFactory factory,
Session session,
Transaction transaction,
String name,
Query query,
List list,
PageBean pb,
HttpServletRequest request)
throws HibernateException {
list = query.list();
pb = new PageBean(list);
query.setFirstResult(pb.getPageStartRow());
query.setMaxResults(pb.getPageRecorders());
list = query.list();
pb.setList(list);
pb.description();
transaction.commit();
session.close();
return pb;
}
public PageBean paging(
SessionFactory factory,
Session session,
Transaction transaction,
String name,
Query query,
List list,
PageBean pb,
HttpServletRequest request)
throws HibernateException {
query.setFirstResult(pb.getPageStartRow());
query.setMaxResults(pb.getPageRecorders());
list = query.list();
pb.setList(list);
pb.description();
transaction.commit();
session.close();
return pb;
}
} |
|
msn: Johnny_issc@hotmail.com
|
|
|
|
|
|
|
|
Matrix排名:1340
排名变化: --
用户等级:3
总发贴数:56
总积分(Karma):273
参与分(经验):262
专家分(威望):40
可用分(财富):100
类型:普通用户
注册:2005-10-19
进入XXYMJJ的部落格
|
|
PagingAction.java
/
*
* Created on 2006-3-21
*
* To change the template for this generated file go to
* Window>Preferences>Java>Code Generation>Code and Comments
*/
package com.ibm.hibernate.action;
import java.util.ArrayList;
import java.util.List;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;
import net.sf.hibernate.Hibernate;
import net.sf.hibernate.HibernateException;
import net.sf.hibernate.Query;
import net.sf.hibernate.Session;
import net.sf.hibernate.SessionFactory;
import net.sf.hibernate.Transaction;
import org.apache.struts.action.Action;
import org.apache.struts.action.ActionForm;
import org.apache.struts.action.ActionForward;
import org.apache.struts.action.ActionMapping;
import com.ibm.hibernate.beans.Demo;
import com.ibm.hibernate.beans.PageBean;
import com.ibm.hibernate.form.QueryForm;
import com.strutsrecipes.hibernate.plugin.HibernatePlugIn;
/**
* @author Johnny
*
* To change the template for this generated type comment go to
* Window>Preferences>Java>Code Generation>Code and Comments
*/
public class PagingAction extends Action {
public static final String HQL_DEMO_BYNAME =
"from com.ibm.hibernate.beans.Demo as e where e.name=:tempName";
public static final String HQL_DEMO_BYALL =
"from com.ibm.hibernate.beans.Demo as e ";
public ActionForward execute(
ActionMapping mapping,
ActionForm form,
HttpServletRequest request,
HttpServletResponse response)
throws HibernateException {
SessionFactory factory = null;
Session session = null;
Transaction transaction = null;
Query query = null;
List list = null;
PageBean pb = (PageBean) request.getSession().getAttribute("page");
String action = request.getParameter("action");
QueryForm queryForm = (QueryForm) form;
String name = queryForm.getName();
try {
factory =
(SessionFactory) servlet.getServletContext().getAttribute(
HibernatePlugIn.SESSION_FACTORY_KEY);
session = factory.openSession();
transaction = session.beginTransaction();
//组装Query
if (name == null || name.equals("")) {
query = session.createQuery(HQL_DEMO_BYALL);
} else {
query = session.createQuery(HQL_DEMO_BYNAME);
query.setString("tempName", name);
}
if (action == null || action.equals("null")) { //第一次读取数据
pb = new PageBean();
pb =
pb.pagingFirsttime(
factory,
session,
transaction,
name,
query,
list,
pb,
request);
System.out.println("第一步，数据已经成功传递到Action，action=" + action);
} else {
if (action == "nextPage" || action.equals("nextPage")) {//nextPage
System.out.println("参数action=" + action);
System.out.println("函数pb.getNextPage()准备执行");
pb.getNextPage();
pb =
pb.paging(
factory,
session,
transaction,
name,
query,
list,
pb,
request);
}
if (action == "previousPage"
|| action.equals("previousPage")) {//previousPage
System.out.println("参数action=" + action);
System.out.println("函数pb.getNextPage()准备执行");
pb.getPreviouspage();
pb =
pb.paging(
factory,
session,
transaction,
name,
query,
list,
pb,
request);
}
}
} catch (Exception e) {
e.printStackTrace();
System.out.println("数据库连接出现异常");
}
request.setAttribute("page", pb);
request.getSession().setAttribute("page", pb);
return (mapping.findForward("QuerySuccess"));
}
} |
|
msn: Johnny_issc@hotmail.com
|
|
|
|
|
|
|
|
Matrix排名:1340
排名变化: --
用户等级:3
总发贴数:56
总积分(Karma):273
参与分(经验):262
专家分(威望):40
可用分(财富):100
类型:普通用户
注册:2005-10-19
进入XXYMJJ的部落格
|
|
Jsp 相关部分
<logic:iterate name="page" property="list" id="Demo"
type="com.ibm.hibernate.beans.Demo">
<tr>
<td><bean:define id="idint" name="Demo" property="id" type="Integer" />
<bean:write name="Demo" property="id" /></td>
<td> <bean:write name="Demo" property="name" /></td>
<td><input type="submit" value="Delete"
onclick="transfervalue('<%=idint%>')"></td>
<td><input type="button" onclick="Modify('<%=idint%>')"
value="Modify"></td><TR>
</logic:iterate>
<TABLE width="760" border="1" cellpadding="0" cellspacing="0">
<tr>
<TH><logic:equal name="page" property="hasPreviousPage" value="true">
<html:link page="/query.do?action=previousPage">PreviousPage</html:link>
</logic:equal> <logic:equal name="page" property="hasNextPage"
value="true">
<html:link page="/query.do?action=nextPage">nextPage</html:link>
</logic:equal> <br />
Total Records: <bean:write name="page" property="totalRows" /><br />
Total Pages: <bean:write name="page" property="totalPages" /><br />
CurrentPage: <bean:write name="page" property="currentPage" /><br />
</TH>
</TR>
</TABLE>
|
|
msn: Johnny_issc@hotmail.com
|
|
|
|
|
|
Matrix排名:1340
排名变化: --
用户等级:3
总发贴数:56
总积分(Karma):273
参与分(经验):262
专家分(威望):40
可用分(财富):100
类型:普通用户
注册:2005-10-19
进入XXYMJJ的部落格
|
|
第一次查询的图片
 ，以及后面的图片
 |
|
msn: Johnny_issc@hotmail.com
|
|
|
|
|
|
Matrix排名:29
排名变化: --
用户等级:6
总发贴数:480
总积分(Karma):2474
参与分(经验):1979
专家分(威望):165
可用分(财富):1849
类型:普通用户
昵称:草原上奔跑的烈马
来自:Norther
注册:2005-08-23
进入Norther的部落格
|
|
Matrix排名:1340
排名变化: --
用户等级:3
总发贴数:56
总积分(Karma):273
参与分(经验):262
专家分(威望):40
可用分(财富):100
类型:普通用户
注册:2005-10-19
进入XXYMJJ的部落格
|
|
怎么加5分
昨天晚上写了个PropertyFileManager~~ 然后把那些什么HQL，还有指定的那些全局的变量全部放到properies里面，感觉程序好看多了，不会这么感觉到处都写斯勒的感觉  |
|
msn: Johnny_issc@hotmail.com
|
|
|
|
|
|
Matrix排名:5658
排名变化: --
用户等级:2
总发贴数:1
总积分(Karma):104
参与分(经验):4
专家分(威望):7
可用分(财富):190
类型:普通用户
注册:2004-08-02
|
|
| setFirstResult,setMaxResult效率不高，如果在千万条数据分页时跟蜗牛一样，最高效的应该是直接在sql就分页好 |
|
|
|
|
|
|
|
Matrix排名:478
排名变化: --
用户等级:4
总发贴数:54
总积分(Karma):525
参与分(经验):182
专家分(威望):36
可用分(财富):725
类型:普通用户
昵称:java man
注册:2004-07-08
进入goodsuperstar的部落格
|
|
| 这样子的分页，已经将程序逻辑与分页逻辑耦合，比较难通用 |
|
|
|
|
|
|
|
Matrix排名:1058
排名变化: --
用户等级:3
总发贴数:38
总积分(Karma):320
参与分(经验):162
专家分(威望):7
可用分(财富):400
类型:普通用户
注册:2006-03-20
|
|