一个通用的分页PageBean

最新推荐文章于 2023-07-11 16:02:07 发布

最新推荐文章于 2023-07-11 16:02:07 发布 · 168 阅读

文章标签：

#Struts #Spring #Hibernate #XML #Web

本文详细介绍了Java分页组件的实现方法，包括PageBean类的设计、DAO层的分页查询逻辑及Action层的分页处理过程。通过Struts+Spring+Hibernate框架整合，实现了高效的分页展示。

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package com.ppy.web.util;

import java.util.List;

public class PageBean {
/**
*
*
* @author ppy 2008-10-18 14:3:56
* totalRecords 总记录数
* list 保存分页的数据
* pageNo 当前页
* pageSize 页大小
* query 保存用户查询的字符串,查询分页用
* pageAction 操作分页的Servlet或Action(struts)
* method (struts中DispatchAction中的method)
*
*
*/

private int totalRecords;

private List list;

private int pageNo;

private int pageSize;

private String query;

private String pageAction;

private String method;

public void setPageAction(String pageAction) {
this.pageAction = pageAction;
}

public void setMethod(String method) {
this.method = method;
}

public List getList() {
return list;
}

public void setList(List list) {
this.list = list;
}

public int getPageNo() {
return pageNo;
}

public void setPageNo(int pageNo) {
this.pageNo = pageNo;
}

public int getPageSize() {
return pageSize;
}

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

public int getTotalRecords() {
return totalRecords;
}

public void setTotalRecords(int totalRecords) {
this.totalRecords = totalRecords;
}

public void setQuery(String query) {
this.query = query;
}

/**
* 取得总页数的方法 return
* totalRecords%pageSize==0?(totalRecords/pageSize):(totalRecords/pageSize+1)
*
* @return
*/
public int getTotalPages() {
return (totalRecords + pageSize - 1) / pageSize;
}

/**
* 得到首页
*
* @return
*/
public int getTopPage() {
return 1;
}

/**
* 得到上一页
*
* @return
*/
public int getPreviousPageNo() {
if (pageNo <= 1)
return 1;
else
return (pageNo - 1);
}

/**
* 得到下一页
*
* @return
*/
public int getNextPageNo() {
if (pageNo >= getTotalPages()) {
return getTotalPages() == 0 ? 1 : getTotalPages();
} else {
return pageNo + 1;
}
}

/**
* 得到尾页
*
* @return
*/
public int getBottomPageNo() {
return getTotalRecords() == 0 ? 1 : getTotalPages();
}

//页面分页导航的链接方式一

public String getPageToolBar1() {
String str = "";
str += "<a href='" + pageAction + "?method=" + method + "&userQuery="
+ query + "&pageNo=" + getTopPage() + "&pageSize=" + pageSize
+ "'>首页</a> ";
str += "<a href='" + pageAction + "?method=" + method + "&userQuery="
+ query + "&pageNo=" + getPreviousPageNo() + "&pageSize="
+ pageSize + "'>上一页</a> ";
str += "<a href='" + pageAction + "?method=" + method + "&userQuery="
+ query + "&pageNo=" + getNextPageNo() + "&pageSize="
+ pageSize + "'>下一页</a> ";
str += "<a href='" + pageAction + "?method=" + method + "&userQuery="
+ query + "&pageNo=" + getBottomPageNo() + "&pageSize="
+ pageSize + "'>尾页</a> ";

return str;
}

//页面分页导航的链接方式二

public String getPageToolBar2() {
String str = "";
int pageSplit = (pageNo / 5) * 5;

for (int i = pageSplit - 1; i < (pageSplit + 6); i++) {
if (i <= 0) {

} else if (pageNo == i) {
str += i + " ";
} else if (i > getTotalPages()) {

} else {
str += "<a href='" + pageAction + "?method=" + method
+ "&userQuery=" + query + "&pageNo=" + i + "&pageSize="
+ pageSize + "'>" + i + "</a>" + " ";
}
}
return str;
}

}

以一个表为例来详述分页组件的用法,本例采用的Struts+Spring+Hibernate,分页用的是Hibernate中的方法

表名Product 字段:

id int primary key identity(1,1),
typeid varchar(20),
name varchar(50),
Price float,
meno varchar(100)

1 pojo类和Product.hbm.xml省略

2 ProductDAO类

public class ProductDAO extends HibernateDaoSupport implements IProductDAO {

public List getProducts(final int pageNo, final int pageSize) {

List list = new ArrayList();

list = this.getHibernateTemplate().executeFind(new HibernateCallback() {
public Object doInHibernate(Session session)
throws HibernateException, SQLException {

return session.createQuery("from Product").setFirstResult((pageNo-1)*pageSize).setMaxResults(pageSize).list();

}
});
return list;
}

public int getTotalRecords(String query) {
Integer totalRecords = null;
if (query != null && query.trim().length() != 0) {
totalRecords = (Integer)this.getHibernateTemplate().find("select count(*) from Product a where a.id like ? or a.name like ?",
new Object[]{query + "%", query + "%"}).get(0);
}else {
totalRecords = (Integer)this.getSession().createQuery("select count(*) from Product a").uniqueResult();

}
return totalRecords.intValue();
}

}

3 Action中的代码,本例没有采用DispatchAction,没有使用查询后再分页(PageBean中的query)

public class PageAction extends Action {

private IProductDAO proDAO;

private PageBean pageBean;

public void setPageBean(PageBean pageBean) {
this.pageBean = pageBean;
}

public void setProDAO(IProductDAO proDAO) {
this.proDAO = proDAO;
}

public ActionForward execute(ActionMapping mapping, ActionForm form,
HttpServletRequest request, HttpServletResponse response) {
PageForm pageForm = (PageForm) form;
int pageNo = pageForm.getPageNo();
int pageSize = pageForm.getPageSize();

List list = proDAO.getProducts(pageNo, pageSize);

pageBean.setPageNo(pageNo);
pageBean.setPageSize(pageSize);
pageBean.setTotalRecords(proDAO.getTotalRecords(""));
pageBean.setPageAction("page.do");
pageBean.setList(list);

request.setAttribute("pageBean", pageBean);

return mapping.findForward("paging");
}

}