SSH2实现数据库和界面的分页

分页应该是在我们开发web应用时经常要做的工作，能够比较简洁的实现数据库和视图层的分页十分重要。 在数据库层利用Hibernate进行数据库的分页，将从数据库中查询出的数据封装为javabean；在视图层就可以方便的实现分页。 创建PageBean

1. package com.fishing.common.bean;  
2.  
3. import java.util.List;  
4. @SuppressWarnings("unchecked")  
5. public class PageBean {  
6.       
7.     private List list; // 要返回的某一页的记录列表  
8.  
9.     private int allRow; // 总记录数  
10.     private int totalPage; // 总页数  
11.     private int currentPage; // 当前页  
12.     private int pageSize; // 每页记录数  
13.  
14.       
15.     private boolean isFirstPage; // 是否为第一页  
16.     private boolean isLastPage; // 是否为最后一页  
17.     private boolean hasPreviousPage; // 是否有前一页  
18.     private boolean hasNextPage; // 是否有下一页  
19.  
20.     public List getList() {  
21.         return list;  
22.     }  
23.  
24.     public void setList(List list) {  
25.         this.list = list;  
26.     }  
27.  
28.     public int getAllRow() {  
29.         return allRow;  
30.     }  
31.  
32.     public void setAllRow(int allRow) {  
33.         this.allRow = allRow;  
34.     }  
35.  
36.     public int getTotalPage() {  
37.         return totalPage;  
38.     }  
39.  
40.     public void setTotalPage(int totalPage) {  
41.         this.totalPage = totalPage;  
42.     }  
43.  
44.     public int getCurrentPage() {  
45.         return currentPage;  
46.     }  
47.  
48.     public void setCurrentPage(int currentPage) {  
49.         this.currentPage = currentPage;  
50.     }  
51.  
52.     public int getPageSize() {  
53.         return pageSize;  
54.     }  
55.  
56.     public void setPageSize(int pageSize) {  
57.         this.pageSize = pageSize;  
58.     }  
59.  
60.     /** */ 
61.     /**  
62.      * 初始化分页信息  
63.      */ 
64.     public void init() {  
65.         this.isFirstPage = isFirstPage();  
66.         this.isLastPage = isLastPage();  
67.         this.hasPreviousPage = isHasPreviousPage();  
68.         this.hasNextPage = isHasNextPage();  
69.     }  
70.  
71.     /** */ 
72.     /**  
73.      * 以下判断页的信息,只需getter方法(is方法)即可  
74.      *   
75.      * @return  
76.      */ 
77.  
78.     public boolean isFirstPage() {      
79.         return (currentPage == 1);// 如是当前页是第1页      
80.     }     
81.     public boolean isLastPage() {      
82.  return currentPage == totalPage; //如果当前页是最后一页      
83. }     
84.     public boolean isHasPreviousPage() {      
85.  return currentPage != 1; //只要当前页不是第1页      
86. }     
87.     public boolean isHasNextPage() {      
88.  return currentPage != totalPage; //只要当前页不是最后1页      
89. }     
90.     /** */ 
91.     /**  
92.      * 计算总页数,静态方法,供外部直接通过类名调用  
93.      *   
94.      * @param pageSize  
95.      *            每页记录数  
96.      * @param allRow  
97.      *            总记录数  
98.      * @return 总页数  
99.      */ 
100.     public static int countTotalPage(final int pageSize, final int allRow) {  
101.         int totalPage = allRow % pageSize == 0 ? allRow / pageSize : allRow  
102.                 / pageSize + 1;  
103.         return totalPage;  
104.     }  
105.  
106.     /** */ 
107.     /**  
108.      * 计算当前页开始记录  
109.      *   
110.      * @param pageSize  
111.      *            每页记录数  
112.      * @param currentPage  
113.      *            当前第几页  
114.      * @return 当前页开始记录号  
115.      */ 
116.     public static int countOffset(final int pageSize, final int currentPage) {  
117.         final int offset = pageSize * (currentPage - 1);  
118.         return offset;  
119.     }  
120.  
121.     /** */ 
122.     /**  
123.      * 计算当前页,若为0或者请求的URL中没有"?page=",则用1代替  
124.      *   
125.      * @param page  
126.      *            传入的参数(可能为空,即0,则返回1)  
127.      * @return 当前页  
128.      */ 
129.     public static int countCurrentPage(int page) {  
130.         final int curPage = (page == 0 ? 1 : page);  
131.         return curPage;  
132.     }  
133. }  

在Dao的抽象接口BaseDao中添加方法

1. public List queryForPage(final String hql, final int offset,  
2.             final int length); 

在Dao的实现类JianSheDWDaoImpl中实现方法

1. public List queryForPage(final String hql, final int offset,  
2.             final int length) {  
3.         List list = getHibernateTemplate().executeFind(new HibernateCallback() {  
4.  
5.             public Object doInHibernate(Session session)  
6.                     throws HibernateException, SQLException {  
7.                 Query query = session.createQuery(hql);  
8.                 query.setFirstResult(offset);  
9.                 query.setMaxResults(length);  
10.                 List list = query.list();  
11.                 return list;  
12.  
13.             }  
14.         });  
15.  
16.         return list;  
17.     } 

在service抽象层接口JianSheDWService中添加方法

1. public PageBean queryForPage(int pageSize,int currentPage);  

在service实现类中实现方法

1. public PageBean queryForPage(int pageSize, int page) {  
2.         final String hql = "from JianSheDWBean"; // 查询语句  
3.         int allRow = this.baseDao.getAllRowCount(hql); // 总记录数  
4.         int totalPage = PageBean.countTotalPage(pageSize, allRow); // 总页数  
5.         final int offset = PageBean.countOffset(pageSize, page); // 当前页开始记录  
6.         final int length = pageSize; // 每页记录数  
7.         final int currentPage = PageBean.countCurrentPage(page);  
8.         List<JianSheDWBean> list = this.baseDao.queryForPage(hql, offset, length); // "一页"的记录  
9.  
10.         // 把分页信息保存到Bean中  
11.         PageBean pageBean = new PageBean();  
12.         pageBean.setPageSize(pageSize);  
13.         pageBean.setCurrentPage(currentPage);  
14.         pageBean.setAllRow(allRow);  
15.         pageBean.setTotalPage(totalPage);  
16.         pageBean.setList(list);  
17.         pageBean.init();  
18.         return pageBean;  
19.  
20.     } 

在视图层action中建立分页模型

1. package com.fishing.action.lcq;  
2.  
3.  
4.  
5. import com.fishing.common.bean.JianSheDWBean;  
6. import com.fishing.common.bean.PageBean;  
7. import com.fishing.service.lcq.JianSheDWService;  
8. import com.opensymphony.xwork2.ActionSupport;  
9.  
10. @SuppressWarnings("serial")  
11. public class GetInfoJSDWListAction extends ActionSupport {  
12.  
13.     private int page; // 第几页  
14.  
15.     private PageBean pageBean; // 包含分布信息的bean  
16.  
17.     private JianSheDWBean jianSheDWBean;  
18.     // private PageBean page;  
19.     private JianSheDWService jianSheDWService;  
20.  
21.     public int getPage() {  
22.         return page;  
23.     }  
24.  
25.     public void setPage(int page) {  
26.         this.page = page;  
27.     }  
28.  
29.     public PageBean getPageBean() {  
30.         return pageBean;  
31.     }  
32.  
33.     public void setPageBean(PageBean pageBean) {  
34.         this.pageBean = pageBean;  
35.     }  
36.  
37.     public JianSheDWBean getJianSheDWBean() {  
38.         return jianSheDWBean;  
39.     }  
40.  
41.     public void setJianSheDWBean(JianSheDWBean jianSheDWBean) {  
42.         this.jianSheDWBean = jianSheDWBean;  
43.     }  
44.  
45.     public JianSheDWService getJianSheDWService() {  
46.         return jianSheDWService;  
47.     }  
48.  
49.     public void setJianSheDWService(JianSheDWService jianSheDWService) {  
50.         this.jianSheDWService = jianSheDWService;  
51.     }  
52.  
53.     @Override     
54.      public String execute() throws Exception {      
55.           
56.      //分页的pageBean,参数pageSize表示每页显示记录数,page为当前页      
57.      this.pageBean = jianSheDWService.queryForPage(10, page);      
58.      return SUCCESS;  
59.     }  
60. }  

在jsp中编写分页

1. <tr class="odd"> 
2.                                                     <td> 
3.                                                         &nbsp;  
4.                                                     </td> 
5.                                                     <td> 
6.                                                         <s:if test="%{pageBean.currentPage == 1}">     
7.                                           首页      上一页  
8.                                             </s:if> 
9.                                                         <s:else> 
10.                                                             <a href="jianguan/getJSDWInfos.action?page=1">首页</a> 
11.                                                             <a 
12.                                                                 href="jianguan/getJSDWInfos.action?page=<s:property value="%{pageBean.currentPage-1}"/>" />上一页</a> 
13.  
14.                                                         </s:else> 
15.                                                     </td> 
16.                                                     <td> 
17.                                                         <s:if test="%{pageBean.currentPage != pageBean.totalPage}"> 
18.  
19.                                                             <a 
20.                                                                 href="jianguan/getJSDWInfos.action?page=<s:property value="%{pageBean.currentPage+1}"/>">下一页</a> 
21.                                                             <a 
22.                                                                 href="jianguan/getJSDWInfos.action?page=<s:property value="pageBean.totalPage"/>">尾页  
23.                                                             </a> 
24.                                                         </s:if> 
25.                                                         <s:else>   
26.                                           下一页  尾页   
27.                                             </s:else> 
28.                                                     </td> 
29.  
30.                                                     <td> 
31.                                                         <div align="center"> 
32.                                                             页次  
33.                                                             <s:property value="pageBean.currentPage" /> 
34.                                                             /  
35.                                                             <s:property value="pageBean.totalPage" /> 
36.                                                             &nbsp;&nbsp;&nbsp;共  
37.                                                             <s:property value="pageBean.allRow" /> 
38.                                                             记录  
39.                                                         </div> 
40.                                                         <div align="center"></div> 
41.                                                     </td> 
42.                                                 </tr> 

上面只是代码的实现，没有说明配置文件的配置，读者根据情况配置。