從開始學(xué)習(xí)到現(xiàn)在，一直逃不過分頁役听，學(xué)習(xí)總結(jié)如下。
設(shè)計(jì)思路：
要有一個(gè)對象貫穿前后端表窘，包含了當(dāng)前頁面典予，分頁總條數(shù)，每頁條數(shù)等乐严。
流程：頁面提交當(dāng)前頁數(shù)currentPage-->controller創(chuàng)建一個(gè)Page對象瘤袖，將這個(gè)值設(shè)置到currentPage上，傳給service-->service調(diào)用dao江场，查詢當(dāng)前需要查詢的總條數(shù)扼鞋，設(shè)置到totalNumber，通過這兩個(gè)參數(shù)計(jì)算總頁數(shù)筐高，和數(shù)據(jù)庫查詢用到的兩個(gè)參數(shù)dbIndex占婉，dbEnd泡嘴，Page對象傳給dao-->根據(jù)dbIndex，dbEnd分頁查詢逆济，返回查詢結(jié)果-->對象通過controller返回到頁面酌予，頁面根據(jù)Page顯示總條數(shù)，當(dāng)前頁數(shù)奖慌，總頁數(shù)等抛虫。
注意：分頁查詢最好加order by，否則按照數(shù)據(jù)庫默認(rèn)排序简僧，不能保證每次排序方式都是相同的建椰，查詢結(jié)果會出問題。
Page類
根據(jù)當(dāng)前查詢的總條數(shù)totalNumber岛马， 每頁顯示幾條pageNumber棉姐，準(zhǔn)備顯示哪一頁currentPage，計(jì)算出總共有多少頁totalNumber蛛枚， 和數(shù)據(jù)庫查詢時(shí)需要的兩個(gè)參數(shù)dbIndex谅海，dbEnd
/**
* 分頁對應(yīng)的實(shí)體類
*/
public class Page {
/**
* 總條數(shù)
*/
private int totalNumber;
/**
* 當(dāng)前第幾頁
*/
private int currentPage;
/**
* 總頁數(shù)
*/
private int totalPage;
/**
* 每頁顯示條數(shù)
*/
private int pageNumber = 10;
/**
* 數(shù)據(jù)庫中l(wèi)imit的參數(shù)，從第幾條開始缺钠帧（dbIndex, dbNumber配合在mysql中使用）
*/
private int dbIndex;
/**
* 數(shù)據(jù)庫中l(wèi)imit的參數(shù)扭吁，一共取多少條
*/
private int dbNumber;
// 取到第幾條（dbIndex, dbEnd配合在oracle中使用）
private int dbEnd;
/**
* 根據(jù)當(dāng)前對象中屬性值計(jì)算并設(shè)置相關(guān)屬性值
*/
public void count() {
// 計(jì)算總頁數(shù)
int totalPageTemp = this.totalNumber / this.pageNumber;
int plus = (this.totalNumber % this.pageNumber) == 0 ? 0 : 1;
totalPageTemp = totalPageTemp + plus;
if(totalPageTemp <= 0) {
totalPageTemp = 1;
}
this.totalPage = totalPageTemp;
// 設(shè)置當(dāng)前頁數(shù)
// 總頁數(shù)小于當(dāng)前頁數(shù)，應(yīng)將當(dāng)前頁數(shù)設(shè)置為總頁數(shù)
if(this.totalPage < this.currentPage) {
this.currentPage = this.totalPage;
}
// 當(dāng)前頁數(shù)小于1設(shè)置為1
if(this.currentPage < 1) {
this.currentPage = 1;
}
// 設(shè)置limit的參數(shù)
this.dbIndex = (this.currentPage - 1) * this.pageNumber;
this.dbNumber = this.pageNumber;
this.dbEnd = this.dbIndex + this.dbNumber;
}
public int getTotalNumber() {
return totalNumber;
}
public void setTotalNumber(int totalNumber) {
this.totalNumber = totalNumber;
this.count();
}
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;
}
public int getPageNumber() {
return pageNumber;
}
public void setPageNumber(int pageNumber) {
this.pageNumber = pageNumber;
this.count();
}
public int getDbIndex() {
return dbIndex;
}
public void setDbIndex(int dbIndex) {
this.dbIndex = dbIndex;
}
public int getDbNumber() {
return dbNumber;
}
public void setDbNumber(int dbNumber) {
this.dbNumber = dbNumber;
}
public int getDbEnd() {
return dbEnd;
}
public void setDbEnd(int dbEnd) {
this.dbEnd = dbEnd;
}
@Override
public String toString() {
return "Page [totalNumber=" + totalNumber + ", currentPage="
+ currentPage + ", totalPage=" + totalPage + ", pageNumber="
+ pageNumber + ", dbIndex=" + dbIndex + ", dbNumber="
+ dbNumber + ", dbEnd=" + dbEnd + "]";
}
}
jsp
<input type="hidden" name="currentPage" id="currentPage" value="${PAGE.currentPage}"/>
<div class=''>
共 <b>${PAGE.totalNumber}</b> 條
<c:if test="${PAGE.currentPage != 1}">
<a href="javascript:changeCurrentPage('${SHEETID}', '1')" class='first'>首頁</a>
<a href="javascript:changeCurrentPage('${SHEETID}', '${PAGE.currentPage-1}')" class='pre'>上一頁</a>
</c:if>
當(dāng)前第<span>${PAGE.currentPage}/${PAGE.totalPage}</span>頁
<c:if test="${PAGE.currentPage != PAGE.totalPage}">
<a href="javascript:changeCurrentPage('${SHEETID}', '${PAGE.currentPage+1}')" class='next'>下一頁</a>
<a href="javascript:changeCurrentPage('${SHEETID}', '${PAGE.totalPage}')" class='last'>末頁</a>
</c:if>
跳至 <input id="currentPageText" type='text' value='${PAGE.currentPage}' class='allInput w28' style="width: 3%;"/> 頁
<a href="javascript:changeCurrentPage('${SHEETID}', $('#currentPageText').val())" class='go'>GO</a>
</div>
<script type="text/javascript">
//修改當(dāng)前頁碼盲镶，調(diào)用后臺重新查詢
function changeCurrentPage(sheetid, currentPage) {
$("#currentPage").val(currentPage);
var currentPageVal = $("#currentPage").val();
console.log("currentPageVal:" + currentPageVal);
// 獲取tabIndex
var TABINDEX = $('#TABINDEX').val();
window.location.href = '<%=basePath %>data/findRequireListBySheetId/' + sheetid + '/' + currentPageVal + '/' + TABINDEX;
}
</script>
controller 創(chuàng)建Page對象侥袜，設(shè)置當(dāng)前頁數(shù)
@RequestMapping(value = "/findRequireListBySheetId/{sheetId}/{currentPage}/{tabIndex}", method=RequestMethod.GET)
public String findRequireListBySheetId(@PathVariable String sheetId,
@PathVariable String currentPage, @PathVariable String tabIndex, Map<String, Object> model) {
// 創(chuàng)建分頁對象
Page page = new Page();
Pattern pattern = Pattern.compile("[0-9]{1,9}");
// 如果當(dāng)前頁為空，或者不符合正則表達(dá)式溉贿，就設(shè)為第1頁
if(currentPage == null || !pattern.matcher(currentPage).matches()) {
page.setCurrentPage(1);
} else {
page.setCurrentPage(Integer.valueOf(currentPage));
}
// 獲取requirelist列表
List<Map<String, String>> requireList = dataService.findRequireListBySheetIdPage(sheetId, page);
model.put(ReturnConstant.FIND_REQUIRE_LIST_BY_SHEETID_PAGE, requireList);
model.put(ReturnConstant.PAGE, page);
model.put(ReturnConstant.SHEETID, sheetId);
model.put(ReturnConstant.TABINDEX, tabIndex);
logger.info("當(dāng)前tabIndex：" + tabIndex);
return "/requireList";
}
service 調(diào)用dao
public List<Map<String, String>> findRequireListBySheetIdPage(String sheetId, Page page) {
Map<String,Object> map = new HashMap<String, Object>();
if("null".equals(sheetId)) {
map.put("sheetId", null);
} else {
map.put("sheetId", sheetId);
}
map.put("page", page);
// 分頁查詢并返回結(jié)果
return requireDao.findRequireListBySheetIdPage(map);
}
RequireMapping.xml 沒有加分頁枫吧，分頁邏輯在攔截器中實(shí)現(xiàn)，見下一節(jié)宇色。有排序九杂。
<select id="findRequireListBySheetIdPage" parameterType="java.util.Map" resultType="java.util.HashMap" >
select t1.*, ermuser.realname from ermuser join (
select ermrequire.*, ermusersheet.userid from ermrequire join ermusersheet on
(ermrequire.sheetid = ermusersheet.sheetid)
<choose>
<when test="sheetId != null">
WHERE ermrequire.sheetid = #{sheetId} order by to_number(serialno)
</when>
<otherwise>
order by to_date(ermrequire.requireaccepttime, 'yyyy/mm/dd')
</otherwise>
</choose>
) t1 on (ermuser.userid = t1.userid)
</select>
