关于Javaweb分页处理以及导航栏实现小记

对于搜索功能结果展示的分页处理，首先应该明确的是目前页，每页显示数据的条数，以及总的数据数目。

接下来，通过这些数据来计算出总的显示页数，以及数据库语句limit查询的范围。

Object result：是分页显示的数据，这里设置为Object的目的是为了方便通过JSON传输。

  1 public class PageBean {
  2     private int pageNum; // 当前页，从请求那边传过来
  3     private int pageSize; // 每页显示的数据条数
  4     private int totalRecord; //总的记录条数
  5     
  6     private int totalPage; // 总页数：totalRecord/pageSize
  7     private int startIndex; // 从第几行开始查数据
  8     
  9     private Object result; // JSON封装好的数据
 10     
 11     // 分页显示的页数，比如在页数上显示1，2，3，4，5.start就是1，end就是5
 12     private int start;
 13     private int end;
 14     
 15     public PageBean(int pageNum, int pageSize, int totalRecord) {
 16         this.pageNum = pageNum;
 17         this.pageSize = pageSize;
 18         this.totalRecord = totalRecord;
 19         
 20         // 计算总页数
 21         if (totalRecord % pageSize == 0) {// 总的数据正好整除每页所显示数据
 22             this.totalPage = totalRecord / pageSize;
 23         } else {
 24             // 不整除，页数+1
 25             this.totalPage = totalRecord / pageSize + 1;
 26         }
 27         
 28         // 数据库查询索引
 29         this.startIndex = (pageNum - 1) * pageSize;
 30         // 显示5页
 31         this.start = 1;
 32         this.end = 5;
 33         
 34         // 显示页数的算法
 35         if (totalPage <= 5) {// 总页数小于5页
 36             this.end = this.totalPage;
 37         } else {
 38             // 总页数是大于5的，那么就要根据当前是第几页来判断显示的start和end
 39             this.start = pageNum - 2;
 40             this.end = pageNum + 2;
 41             
 42             if (start <= 0) {
 43                 this.start = 1;
 44                 this.end = 5;
 45             }
 46             if (end > this.totalPage) {
 47                 this.end = totalPage;
 48                 this.start = end - 4;
 49             }
 50         }
 51         
 52     }
 53 
 54     public int getPageNum() {
 55         return pageNum;
 56     }
 57 
 58     public void setPageNum(int pageNum) {
 59         this.pageNum = pageNum;
 60     }
 61 
 62     public int getPageSize() {
 63         return pageSize;
 64     }
 65 
 66     public void setPageSize(int pageSize) {
 67         this.pageSize = pageSize;
 68     }
 69 
 70     public int getTotalRecord() {
 71         return totalRecord;
 72     }
 73 
 74     public void setTotalRecord(int totalRecord) {
 75         this.totalRecord = totalRecord;
 76     }
 77 
 78     public int getTotalPage() {
 79         return totalPage;
 80     }
 81 
 82     public void setTotalPage(int totalPage) {
 83         this.totalPage = totalPage;
 84     }
 85 
 86     public int getStartIndex() {
 87         return startIndex;
 88     }
 89 
 90     public void setStartIndex(int startIndex) {
 91         this.startIndex = startIndex;
 92     }
 93 
 94     public Object getResult() {
 95         return result;
 96     }
 97 
 98     public void setResult(Object result) {
 99         this.result = result;
100     }
101 
102     public int getStart() {
103         return start;
104     }
105 
106     public void setStart(int start) {
107         this.start = start;
108     }
109 
110     public int getEnd() {
111         return end;
112     }
113 
114     public void setEnd(int end) {
115         this.end = end;
116     }
117     
118     
119 }

持久层主要是得到PageBean对象里的startIndex和pageSize数据来进行limit查询

代码如下：

 1 public class SearchUtils {
 2     /**
 3      * 通过模糊匹配帖子标题查询所有帖子信息（themeId,themeTitle,createTime,userID,nickName,boardId,
 4      * boardNamereadCount,postCount,）
 5      * 
 6      * @param keyWord
 7      * @return
 8      */
 9     public static List<Object> searchByThemeTitle(String keyWord) {
10         List<Object> searchResult = null;
11         String sql = "select bt.themeId, bt.themeTitle,bt.createTime,bt.userID,u.nickName,bt.boardId,sb.smallBoardName,bt.readCount,bt.postCount,bt.content, bb.bigBoardName from bbs_theme bt, `user` u, smallboard sb, bigboard bb where bt.boardId = sb.smallBoardId and bt.userID = u.userID and sb.parentId=bb.bigBoardId and bt.themeTitle like '%"+keyWord+"%' order by bt.readCount DESC";
12         Session session = HibernateSessionFactory.openSession();
13         try {
14             SQLQuery sqlQuery = session.createSQLQuery(sql);
15             searchResult = sqlQuery.list();
16         } catch (Exception e) {
17             e.printStackTrace();
18         } finally {
19             session.close();
20         }
21         return searchResult;
22     }
23     
24     /**
25      * 分页查询
26      * @param start
27      * @param end
28      * @param keyWord
29      * @return
30      */
31     public static List<Object> searchByThemeTitle(int start, int end, String keyWord) {
32         List<Object> searchResult = null;
33         String sql = "select bt.themeId, bt.themeTitle,bt.createTime,bt.userID,u.nickName,bt.boardId,sb.smallBoardName,bt.readCount,bt.postCount,bt.content, bb.bigBoardName from bbs_theme bt, `user` u, smallboard sb, bigboard bb where bt.boardId = sb.smallBoardId and bt.userID = u.userID and sb.parentId=bb.bigBoardId and bt.themeTitle like '%"+keyWord+"%' order by bt.readCount DESC limit "+start+","+end;
34         Session session = HibernateSessionFactory.openSession();
35         try {
36             SQLQuery sqlQuery = session.createSQLQuery(sql);
37             searchResult = sqlQuery.list();
38         } catch (Exception e) {
39             e.printStackTrace();
40         } finally {
41             session.close();
42         }
43         return searchResult;
44     }
45 }

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