1 package com.jxpx.myums.domain;
  2 
  3 import java.util.List;
  4 
  5 public class PageBean<T> {
  6     //已知数据
  7     private int pageNum;    //当前页,从请求那边传过来。
  8     private int pageSize;    //每页显示的数据条数。
  9     private int totalRecord;    //总的记录条数。查询数据库得到的数据
 10     
 11     //需要计算得来
 12     private int totalPage;    //总页数，通过totalRecord和pageSize计算可以得来
 13     //开始索引，也就是我们在数据库中要从第几行数据开始拿，有了startIndex和pageSize，
 14     //就知道了limit语句的两个数据，就能获得每页需要显示的数据了
 15     private int startIndex;        
 16         
 17     
 18     //将每页要显示的数据放在list集合中
 19     private List<T> list;
 20     
 21     //分页显示的页数,比如在页面上显示1，2，3，4，5页，start就为1，end就为5，这个也是算过来的
 22     private int start;
 23     private int end;
 24     
 25     //通过pageNum，pageSize，totalRecord计算得来tatalPage和startIndex
 26     //构造方法中将pageNum，pageSize，totalRecord获得
 27     public PageBean(int pageNum,int pageSize,int totalRecord) {
 28         this.pageNum = pageNum;
 29         this.pageSize = pageSize;
 30         this.totalRecord = totalRecord;
 31         
 32         //totalPage 总页数
 33         if(totalRecord%pageSize==0){
 34             //说明整除，正好每页显示pageSize条数据，没有多余一页要显示少于pageSize条数据的
 35             this.totalPage = totalRecord / pageSize;
 36         }else{
 37             //不整除，就要在加一页，来显示多余的数据。
 38             this.totalPage = totalRecord / pageSize +1;
 39         }
 40         //开始索引
 41         this.startIndex = (pageNum-1)*pageSize ;
 42         //显示5页，这里自己可以设置，想显示几页就自己通过下面算法修改
 43         this.start = 1;
 44         this.end = 5;
 45         //显示页数的算法
 46 
 47         if(totalPage <=5){
 48             //总页数都小于5，那么end就为总页数的值了。
 49             this.end = this.totalPage;
 50         }else{
 51             //总页数大于5，那么就要根据当前是第几页，来判断start和end为多少了，
 52             this.start = pageNum - 2;
 53             this.end = pageNum + 2;
 54             
 55             if(start < 0){
 56                 //比如当前页是第1页，或者第2页，那么就不如和这个规则，
 57                 this.start = 1;
 58                 this.end = 5;
 59             }
 60             if(end > this.totalPage){
 61                 //比如当前页是倒数第2页或者最后一页，也同样不符合上面这个规则
 62                 this.end = totalPage;
 63                 this.start = end - 5;
 64             }
 65         }
 66     }
 67 //get、set方法。
 68     public int getPageNum() {
 69         return pageNum;
 70     }
 71 
 72     public void setPageNum(int pageNum) {
 73         this.pageNum = pageNum;
 74     }
 75 
 76     public int getPageSize() {
 77         return pageSize;
 78     }
 79 
 80     public void setPageSize(int pageSize) {
 81         this.pageSize = pageSize;
    }

 84     public int getTotalRecord() {
 85         return totalRecord;
 86     }
 87 
 88     public void setTotalRecord(int totalRecord) {
 89         this.totalRecord = totalRecord;
 90     }
 91 
 92     public int getTotalPage() {
 93         return totalPage;
 94     }
 95 
 96     public void setTotalPage(int totalPage) {
 97         this.totalPage = totalPage;
 98     }
 99 
100     public int getStartIndex() {
101         return startIndex;
102     }
103 
104     public void setStartIndex(int startIndex) {
105         this.startIndex = startIndex;
106     }
107 
108     public List<T> getList() {
109         return list;
110     }
111 
112     public void setList(List<T> list) {
113         this.list = list;
114     }
115 
116     public int getStart() {
117         return start;
118     }
119 
120     public void setStart(int start) {
121         this.start = start;
122     }
123 
124     public int getEnd() {
125         return end;
126     }
127 
128     public void setEnd(int end) {
129         this.end = end;
130     }
131     
132 
}

 1             <%-- 构建分页导航 --%>
 2             共有${requestScope.pageBean.totalRecord}个员工，共${requestScope.pageBean.totalPage }页，当前为${requestScope.pageBean.pageNum}页
 3             <br/>
 4             <a href="${pageContext.request.contextPath}/FindAllWithPage?pageNum=1">首页</a>
 5             <%--如果当前页为第一页时，就没有上一页这个超链接显示 --%>
 6             <c:if test="${requestScope.pageBean.pageNum ==1}">
 7                 <c:forEach begin="${requestScope.pageBean.start}" end="${requestScope.pageBean.end}" step="1" var="i">
 8                     <c:if test="${requestScope.pageBean.pageNum == i}">
 9                         ${i}
10                     </c:if>                
11                     <c:if test="${requestScope.pageBean.pageNum != i}">
12                         <a href="${pageContext.request.contextPath}/FindAllWithPage?pageNum=${i}">${i}</a>                                        
13                     </c:if>                        
14                 </c:forEach>
15                 <a href="${pageContext.request.contextPath}/FindAllWithPage?pageNum=${requestScope.pageBean.pageNum+1}">下一页</a>                    
16             </c:if>
17             
18             <%--如果当前页不是第一页也不是最后一页，则有上一页和下一页这个超链接显示 --%>
19             <c:if test="${requestScope.pageBean.pageNum > 1 && requestScope.pageBean.pageNum < requestScope.pageBean.totalPage}">
20                 <a href="${pageContext.request.contextPath}/FindAllWithPage?pageNum=${requestScope.pageBean.pageNum-1}">上一页</a>
21                 <c:forEach begin="${requestScope.pageBean.start}" end="${requestScope.pageBean.end}" step="1" var="i">    
22                     <c:if test="${requestScope.pageBean.pageNum == i}">
23                         ${i}
24                     </c:if>            
25                     <c:if test="${requestScope.pageBean.pageNum != i}">
26                         <a href="${pageContext.request.contextPath}/FindAllWithPage?pageNum=${i}">${i}</a>                                        
27                     </c:if>                        
28                 </c:forEach>
29                 <a href="${pageContext.request.contextPath}/FindAllWithPage?pageNum=${requestScope.pageBean.pageNum+1}">下一页</a>    
30             </c:if>
31             
32             <%-- 如果当前页是最后一页，则只有上一页这个超链接显示，下一页没有 --%>
33             <c:if test="${requestScope.pageBean.pageNum == requestScope.pageBean.totalPage}">
34                 <a href="${pageContext.request.contextPath}/FindAllWithPage?pageNum=${requestScope.pageBean.pageNum-1}">上一页</a>
35                 <c:forEach begin="${requestScope.pageBean.start}" end="${requestScope.pageBean.end}" step="1" var="i">
36                     <c:if test="${requestScope.pageBean.pageNum == i}">
37                         ${i}
38                     </c:if>
39                     <c:if test="${requestScope.pageBean.pageNum != i}">
40                         <a href="${pageContext.request.contextPath}/FindAllWithPage?pageNum=${i}">${i}</a>                                        
41                     </c:if>                
42                 </c:forEach>
43             </c:if>
44             <%--尾页 --%>
45             <a href="${pageContext.request.contextPath}/FindAllWithPage?pageNum=${requestScope.pageBean.totalPage}">尾页</a>