关键字: j2ee 网页 struts 分页算法

/**

* 分页算法

*/

package cn.eshore.user.util;

public class PageBean {

private int currentPage = 1;// 当前页数

public int totalPages = 0;// 总页数

private int pageSize = 0;// 每页显示数

private int totalRows = 0;// 总数据数

private int startNum = 0;// 开始记录

private int nextPage = 0;// 下一页

private int previousPage = 0;// 上一页

private boolean hasNextPage = false;// 是否有下一页

private boolean hasPreviousPage = false;// 是否有前一页

public PageBean(int pageSize, int currentPage, int totalRows) {

this.pageSize = pageSize;

this.currentPage = currentPage;

this.totalRows = totalRows;

if ((totalRows % pageSize) == 0) {

totalPages = totalRows / pageSize;

} else {

totalPages = totalRows / pageSize + 1;

}

if (currentPage >= totalPages) {

hasNextPage = false;

currentPage = totalPages;

} else {

hasNextPage = true;

}

if (currentPage <= 1) {

hasPreviousPage = false;

currentPage = 1;

} else {

hasPreviousPage = true;

}

startNum = (currentPage - 1) * pageSize;

nextPage = currentPage + 1;

if (nextPage >= totalPages) {

nextPage = totalPages;

}

previousPage = currentPage - 1;

if (previousPage <= 1) {

previousPage = 1;

}

}

public boolean isHasNextPage() {

return hasNextPage;

}

public boolean isHasPreviousPage() {

return hasPreviousPage;

}

/**

* @return the nextPage

*/

public int getNextPage() {

return nextPage;

}

/**

* @param nextPage

*            the nextPage to set

*/

public void setNextPage(int nextPage) {

this.nextPage = nextPage;

}

/**

* @return the previousPage

*/

public int getPreviousPage() {

return previousPage;

}

/**

* @param previousPage

*            the previousPage to set

*/

public void setPreviousPage(int previousPage) {

this.previousPage = previousPage;

}

/**

* @return the currentPage

*/

public int getCurrentPage() {

return currentPage;

}

/**

* @param currentPage

*            the currentPage to set

*/

public void setCurrentPage(int currentPage) {

this.currentPage = currentPage;

}

/**

* @return the pageSize

*/

public int getPageSize() {

return pageSize;

}

/**

* @param pageSize

*            the pageSize to set

*/

public void setPageSize(int pageSize) {

this.pageSize = pageSize;

}

/**

* @return the totalPages

*/

public int getTotalPages() {

return totalPages;

}

/**

* @param totalPages

*            the totalPages to set

*/

public void setTotalPages(int totalPages) {

this.totalPages = totalPages;

}

/**

* @return the totalRows

*/

public int getTotalRows() {

return totalRows;

}

/**

* @param totalRows

*            the totalRows to set

*/

public void setTotalRows(int totalRows) {

this.totalRows = totalRows;

}

/**

* @param hasNextPage

*            the hasNextPage to set

*/

public void setHasNextPage(boolean hasNextPage) {

this.hasNextPage = hasNextPage;

}

/**

* @param hasPreviousPage

*            the hasPreviousPage to set

*/

public void setHasPreviousPage(boolean hasPreviousPage) {

this.hasPreviousPage = hasPreviousPage;

}

/**

* @return the startNum

*/

public int getStartNum() {

return startNum;

}

/**

* @param startNum

*            the startNum to set

*/

public void setStartNum(int startNum) {

this.startNum = startNum;

}

}

如果你使用的是struts，那么你在调用这个PageBean分页算法之前，你得先取得对你所想要进行分页的数据的总记录数，然后你就实例化这个PageBean，之后你就可以通过get方法得到任何你想要的值。

package test;

import cn.eshore.user.util.PageBean;

public class Test extends DispatchAction{

......

public ActionForward loadPageUser(ActionMapping mapping, ActionForm form,

HttpServletRequest request, HttpServletResponse response) {

.......

int pageSize = 5;

String pageId = request.getParameter("pageId");

if (pageId == null || pageId.equals("")) {

pageId = "1";

}

int currentPage = Integer.parseInt(pageId);

//从服务层里得到用户的总记录数

int totalRows = userService.getTotalRows();

PageBean page = new PageBean(pageSize, currentPage, totalRows);

....

}

}