今天看到某人寫的分頁類，結果發現批人家的人不少，沒有必要，好的東西吸收學習，感覺不實用可以不用，何必發帖子挖苦人家。我前段時間也自己設計了一個分頁的方法，絕對是自己想到的，如果網上有一樣的，說明大家都思考了，有可取度，提供給大家參考。
首先寫了一個分頁的類，其實只有主要屬性的setter和getter方法
/**
* 分頁類
* @author qinglin876
*
*/
public class Pagination {
private int start;
//一次取得的數量
private int size;
//要取得頁數
private int currentPage = 1;
//總的記錄頁數
private int totalPage = 0;
//總的記錄條數
private int totalRecord;
public int getTotalRecord() {
return totalRecord;
}
public void setTotalRecord(int totalRecord) {
this.totalRecord = totalRecord;
}
public Pagination(){
}
public Pagination(int size){
this.size = size;
}
public int getSize() {
return size;
}
public void setSize(int size) {
this.size = size;
}
public int getStart() {
return start;
}
public void setStart(int start) {
this.start = start;
}
public int getCurrentPage() {
return currentPage;
}
public void setCurrentPage(int currentPage) {
this.currentPage = currentPage;
}
public int getTotalPage() {
return totalPage;
}
public void setTotalPage(int totalPage) {
this.totalPage = totalPage;
}
}
另外pagination.jsp由pagination類填充
<%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%>
<%@ taglib prefix="s" uri="/struts-tags"%>
<SCRIPT type="text/javascript">
function trim(str){
return str.replace(/(^\s*)|(\s*$)/g, "");
}
function selectPage(input){
var value = trim(input.value);
if(value == ""){
return;
}
if(/\d+/.test(value)){
input.form.submit();
return;
}
alert("請輸入正確的頁數");
input.focus();
}
</SCRIPT>
<div class="pagech">
<s:if test="pagination.totalPage != 0">
<s:url action="%{#request.url}" id="first">
<s:param name="pagination.currentPage" value="1"></s:param>
</s:url>
<s:url action="%{#request.url}" id="next" >
<s:param name="pagination.currentPage"
value="pagination.currentPage+1">
</s:param>
</s:url>
<s:url action="%{#request.url}" id="prior" >
<s:param name="pagination.currentPage"
value="pagination.currentPage-1"></s:param>
</s:url>
<s:url action="%{#request.url}" id="last">
<s:param name="pagination.currentPage" value="pagination.totalPage"></s:param>
</s:url>
<s:if test="pagination.currentPage == 1">
<span class="current">首頁</span>
<span class="current">上一頁</span>
</s:if>
<s:else>
<s:a href="%{first}">首頁</s:a>
<s:a href="%{prior}">上一頁</s:a>
</s:else>
<s:if
test="pagination.currentPage == pagination.totalPage || pagination.totalPage == 0">
<span class="current">下一頁</span>
<span class="current">末頁</span>
</s:if>
<s:else>
<s:a href="%{next}">下一頁</s:a>
<s:a href="%{last}">末頁</s:a>
</s:else>
<span class="jumplabel">跳轉到</span>
<s:form action="%{#request.url}" theme="simple"
cssStyle="display:inline">
<s:hidden name="pagination.totalPage" value="%{pagination.totalPage}"></s:hidden>
<input type="text" name="pagination.currentPage" size="2"
onblur="selectPage(this)" />
</s:form>
<span class="jumplabel">頁</span>
<span class="jumplabel">共<s:property
value="pagination.totalRecord" />條</span>
<span class="jumplabel">當前是第<s:property
value="pagination.currentPage" />/<s:property value="pagination.totalPage"/>頁</span>
</s:if>
</div>
用的時候，在頁面include進去，注意上面的"%{#request.url}"，即是在struts2的action里面有一個setter和getter方法，下面看action中的某個方法
public String showNotices() throws Exception{
if(tip != null){
tip = new String(tip.getBytes("iso8859-1"),"utf-8");
}
if(notices == null)
this.notices = new ArrayList<Notice>();
int size = Integer.valueOf(this.getText("per_page_notice_size"));
if (pagination == null) {
pagination = new Pagination(size);
}
pagination.setSize(size);
if (pagination.getCurrentPage() <= 0) {
pagination.setCurrentPage(1);
}
if (pagination.getTotalPage() != 0
&& pagination.getCurrentPage() > pagination.getTotalPage()) {
pagination.setCurrentPage(pagination.getTotalPage());
}
url = "goto_showNotices.action"; this.notices.addAll(this.noticeDAO.showAll(pagination));
if(this.notices.size() == 0 && pagination.getCurrentPage() != 1){
pagination.setCurrentPage(pagination.getCurrentPage()-1);
this.notices.addAll(this.noticeDAO.showAll(pagination));
}
return "success";
}
在上面的this.noticeDAO.showAll(pagination))中填充pagination，具體如下
/*
* 顯示所有的通告
* @see com.qinglin.dao.NoticeDAO#showAll(com.qinglin.util.Pagination)
*/
@SuppressWarnings("unchecked")
public List<Notice> showAll(final Pagination pagination) {
String hql = "from Notice as n";
this.getHibernateTemplate().setCacheQueries(true);
int totalRecord = ((Long) this.getSession().createQuery(
"select count(*) " + hql).uniqueResult()).intValue();
int totalPage = totalRecord % pagination.getSize() == 0 ? totalRecord
/ pagination.getSize() : totalRecord / pagination.getSize() + 1;
pagination.setTotalRecord(totalRecord);
pagination.setTotalPage(totalPage);
hql += " order by n.add_date desc";
final String hql1 = hql;
return (List<Notice>) this.getHibernateTemplate().execute(
new HibernateCallback() {
public Object doInHibernate(Session session)
throws HibernateException, SQLException {
Query query = session.createQuery(hql1);
query.setFirstResult((pagination.getCurrentPage() - 1)
* pagination.getSize());
query.setMaxResults(pagination.getSize());
return query.list();
}
});
}
基本上就這些，當然請求的action里面需要設置pagination的setter和getter方法
這個分頁方法特點是簡單，只需在action中指明請求的url，用某種方法填充pagination，在顯示的頁面包含pagination.jsp即可。
package com.shop.bean;
import java.util.List;
public class PageView <T> {
private int currentPage = 1;
private long totalPage = 1;
private long totalRecord = 1;
private List <T> records;
private int firstIndex = 1;
private PageIndex pageIndex;
private int maxResult = 12;
public PageView(int currentPage, int maxResult) {
this.currentPage = currentPage;
this.maxResult = maxResult;
this.firstIndex = currentPage * maxResult;
}
public int getCurrentPage() {
return currentPage;
}
public void setCurrentPage(int currentPage) {
this.currentPage = currentPage;
}
public void setQueryResult(QueryResult <T> qr){
setTotalRecord(qr.getTotal());
setRecords(qr.getDatas());
}
public long getTotalPage() {
return totalPage;
}
public void setTotalPage(long totalPage) {
this.totalPage = totalPage;
this.pageIndex = WebTool.getPageIndex(this.maxResult, this.currentPage, this.totalPage);
}
public long getTotalRecord() {
return totalRecord;
}
public void setTotalRecord(long totalRecord) {
this.totalRecord = totalRecord;
setTotalPage(totalRecord / this.maxResult == 0 ? totalRecord / this.maxResult : totalRecord / this.maxResult + 1);
}
public List <T> getRecords() {
return records;
}
public void setRecords(List <T> records) {
this.records = records;
}
public int getFirstIndex() {
return firstIndex;
}
public PageIndex getPageIndex() {
return pageIndex;
}
public void setPageIndex(PageIndex pageIndex) {
this.pageIndex = pageIndex;
}
public int getMaxResult() {
return maxResult;
}
public void setMaxResult(int maxResult) {
this.maxResult = maxResult;
}
public void setFirstIndex(int firstIndex) {
this.firstIndex = firstIndex;
}
}
畫面的代碼：
<s:iterator value="#request.pageView.pageIndex.pageList">
<s:if test="#request.pageView.currentPage == 4"> <b> <font color="#FFFFFF">第 <s:property/>頁 </font> </b> </s:if>
<s:if test="#request.pageView.currentPage != 4"> <a href="javascript:topage( <s:property/>)" class="a03">第 <s:property/>頁 </a> </s:if>
</s:iterator>
action中的代碼：
Map <String, Object> request = (Map <String, Object>)ActionContext.getContext().get("request");
request.put("pageView", pageView);
<s:iterator value="#request.pageView.pageIndex.pageList">中="#request.pageView.pageIndex.pageList值能正常獲取，可是 <s:if test="#request.pageView.currentPage == 4"> 中的="#request.pageView.currentPage值獲取不到正確的值，這是什么原因啊？
問題補充：
<s:iterator value="#request.pageView.pageIndex.pageList">
<s:if test="{#request.pageView.currentPage == 4}"><b><font color="#FFFFFF">第<s:property/>頁</font></b></s:if>
<s:if test="{#request.pageView.currentPage != 4}"><a href="javascript:topage(<s:property/>)" class="a03">第<s:property/>頁</a></s:if>
</s:iterator>