1、首先，新建一个类Page.java
1 public class Page implements Serializable {
2 private static final long serialVersionUID = -3198048449643774660L;
3 private int pageNow = 1; // 当前页数
4 private int pageSize = 10; // 每页显示记录的条数
5 private int totalCount; // 总记录条数
6 private int totalPageCount; // 总页数
7 private int startPos; // 开始位置，从0开始
8 //构造函数,参数：总记录数和当前页
9 public Page(int totalCount, int pageNow) {
10 this.totalCount = totalCount;
11 this.pageNow = pageNow;
12 }
13 //计算总页数，总页数=总记录数/每页显示记录的条数
14 public int getTotalPageCount() {
15 totalPageCount = getTotalCount() / getPageSize();
16 return (totalCount % pageSize == 0) ? totalPageCount : totalPageCount + 1;
17 }
18 public void setTotalPageCount(int totalPageCount) {
19 this.totalPageCount = totalPageCount;
20 }
21 public int getPageNow() {
22 return pageNow;
23 }
24 public void setPageNow(int pageNow) {
25 this.pageNow = pageNow;
26 }
27 public int getPageSize() {
28 return pageSize;
29 }
30 public void setPageSize(int pageSize) {
31 this.pageSize = pageSize;
32 }
33 public int getTotalCount() {
34 return totalCount;
35 }
36 public void setTotalCount(int totalCount) {
37 this.totalCount = totalCount;
38 }
39 //取得选择记录的初始位置
40 public int getStartPos() {
41 return (pageNow - 1) * pageSize;
42 }
43 }2、在Dao层加入两个方法，分别获取总的记录数和每页显示的list集合，DBUtil.java是数据库工具类。
1 // 获取总的记录数
2 public static int getCount() throws SQLException {
3 Connection conn = DBUtil.getConn();
4 PreparedStatement pst = null;
5 String sql = "select count(*) from users";
6 pst = conn.prepareStatement(sql);
7 ResultSet rs = pst.executeQuery();
8 int count=0;
9 if(rs.next()){
10 count=rs.getInt(1);
11 }
12 DBUtil.close(conn, pst, rs);
13 return count;
14 }
15 // 分页查找
16 public static ArrayList<Users> findByPage(int pos, int size) throws SQLException {
17 Connection conn = DBUtil.getConn();
18 ArrayList<Users> userList = new ArrayList<Users>();
19 PreparedStatement pst = null;
20 String sql = "select * from users limit ?,?";
21 pst = conn.prepareStatement(sql);
22 pst.setInt(1, pos);
23 pst.setInt(2, size);
24 ResultSet rs = pst.executeQuery();
25 while (rs.next()) {
26 Users user = new Users();
27 user.setUserid(rs.getInt(1));
28 user.setUsername(rs.getString(2));
29 }
30 DBUtil.close(conn, pst, rs);
31 return userList;
32 }3、在Servlet中调用Dao层的方法，并向页面传递参数，
1 String pageNow=request.getParameter("pageNow");//获取当前页
2 int totalCount=UsersDao.getCount();//获取总的记录数
3 List<Users> userList=new ArrayList<Users>();
4 Page page=null;
5 if(pageNow!=null){
6 page=new Page(totalCount, Integer.parseInt(pageNow));
7 userList=UsersDao.findByPage(page.getStartPos(), page.getPageSize());//从startPos开始，获取pageSize条数据
8 }else{
9 page=new Page(totalCount, 1);//初始化pageNow为1
10 userList=UsersDao.findByPage(page.getStartPos(), page.getPageSize());//从startPos开始，获取pageSize条数据
11 }
12 request.setAttribute("page", page);
13 request.setAttribute("userList", userList);
14 request.getRequestDispatcher("/WEB-INF/views/homePage.jsp").forward(request, response);4、在jsp页面中添加如下代码：
1 <body>
2 <div class="page_nav">
3 <c:choose>
4 <c:when test="${page.totalPageCount <= 10}"><!-- 如果总页数小于10，则全部显示 -->
5 <c:set var="begin" value="1"></c:set>
6 <c:set var="end" value="${page.totalPageCount }"></c:set>
7 </c:when>
8 <c:when test="${page.pageNow <= 5 }"><!-- 如果总页数小于5，则显示1-10页 -->
9 <c:set var="begin" value="1"></c:set>
10 <c:set var="end" value="10"></c:set>
11 </c:when>
12 <c:otherwise><!-- 否则，显示前5页和后5页，保证当前页在中间 -->
13 <c:set var="begin" value="${page.pageNow-5 }"></c:set>
14 <c:set var="end" value="${page.pageNow+5 }"></c:set>
15 <c:if test="${end > page.totalPageCount }"><!-- 如果end值小于总的记录数，则显示最后10页 -->
16 <c:set var="end" value="${page.totalPageCount}"></c:set>
17 <c:set var="begin" value="${end-10 }"></c:set>
18 </c:if>
19 </c:otherwise>
20 </c:choose>
21 <c:choose>
22 <c:when test="${page.pageNow != 1 }"><!-- 如果当前页为1，则不显示首页和上一页 -->
23 <a href="?oper=login&pageNow=1">首页</a>
24 <a href="?oper=login&pageNow=${page.pageNow-1 }">上一页</a>
25 </c:when>
26 </c:choose>
27 <!-- 遍历页码 -->
28 <c:forEach begin="${begin }" end="${end }" var="index">
29 <c:choose>
30 <c:when test="${page.pageNow == index }"><!-- 如果为当前页，则特殊显示 -->
31 <a style="height:24px; margin:0 3px; border:none; background:#C00;">${index}</a>
32 </c:when>
33 <c:otherwise><!-- 否则，普通显示 -->
34 <a href="?oper=login&pageNow=${index }">${index }</a>
35 </c:otherwise>
36 </c:choose>
37 </c:forEach>
38 <c:choose>
39 <c:when test="${page.pageNow != page.totalPageCount }"><!-- 如果当前页为总的记录数，则不显示末页和下一页 -->
40 <a href="?oper=login&pageNow=${page.pageNow+1 }">下一页</a>
41 <a href="?oper=login&pageNow=${page.totalPageCount }">末页</a>
42 </c:when>
43 </c:choose>
44 共${page.totalPageCount }页，${page.totalCount }条记录 到第<input
45 value="${page.pageNow }" name="pn" id="pn_input" />页 <input
46 id="pn_btn" type="button" value="确定">
47 <script type="text/javascript">
48 //为按钮绑定一个单击响应函数
49 $("#pn_btn").click(function() {
50 //获取到要跳转的页码
51 var pageNow = $("#pn_input").val();
52 //通过修改window.location属性跳转到另一个页面
53 window.location = "?oper=login&pageNow=" + pageNow;
54 });
55 </script>
56 </div>
57 </body>最后附上数据库工具类代码DBUtil：
1 package com.bwlu.common;
2
3 import java.sql.Connection;
4 import java.sql.DriverManager;
5 import java.sql.PreparedStatement;
6 import java.sql.ResultSet;
7 import java.sql.SQLException;
8
9 public class DBUtil {
10
11 private static String DRIVER = null;
12
13 private static String URL = null;
14
15 private static String USERNAME = null;
16
17 private static String PASSWORD = null;
18
19 static {
20 DRIVER = "com.mysql.jdbc.Driver";
21 URL = "jdbc:mysql://localhost:3306/mytest";
22 USERNAME = "root";
23 PASSWORD = "mysql";
24 }
25
26 public static Connection getConn() {
27 Connection conn = null;
28 try {
29 /* 加载驱动 */
30 // System.out.println(DRIVER);
31 Class.forName(DRIVER);
32 /* 获取连接 */
33 conn = DriverManager.getConnection(URL, USERNAME, PASSWORD);
34
35 } catch (ClassNotFoundException e) {
36 e.printStackTrace();
37 } catch (SQLException e) {
38 e.printStackTrace();
39 }
40 return conn;
41 }
42
43 // 关闭连接
44 public static void close(Connection conn, PreparedStatement ps, ResultSet rs) {
45 try {
46 if (rs != null) {
47 rs.close();
48 }
49 if (ps != null) {
50 ps.close();
51 }
52 if (conn != null) {
53 conn.close();
54 }
55 } catch (SQLException e) {
56 e.printStackTrace();
57 }
58 }
59 }DBUtil
SSM框架中【MyBatis分页语句】
UsersMapper.java
1 public interface UsersMapper {
2 // 获取分页记录,startPos:从第几行开始获取，pageSize:获取的条数
3 List<Users> selectByPage(@Param(value = "startPos") Integer startPos,
4 @Param(value = "pageSize") Integer pageSize);
5 // 获取数据库总的记录数，返回users表中总的记录条数
6 int getCount();
7 }UsersMapper.xml
1 <?xml version="1.0" encoding="UTF-8" ?>
2 <!DOCTYPE mapper PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN" "http://mybatis.org/dtd/mybatis-3-mapper.dtd" >
3 <mapper namespace="com.bwlu.mapper.UsersMapper" >
4 <resultMap id="BaseResultMap" type="com.bwlu.bean.Users" >
5 <id column="userId" property="userid" jdbcType="INTEGER" />
6 <result column="userName" property="username" jdbcType="VARCHAR" />
7 <result column="password" property="password" jdbcType="VARCHAR" />
8 <result column="userEmail" property="useremail" jdbcType="VARCHAR" />
9 <result column="permission" property="permission" jdbcType="INTEGER" />
10 </resultMap>
11
12 <!-- 分页SQL语句 -->
13 <select id="selectByPage" resultMap="BaseResultMap">
14 select * from Users limit #{startPos},#{pageSize}
15 </select>
16 <!-- 取得记录的总数 -->
17 <select id="getCount" resultType="java.lang.Integer">
18 SELECT COUNT(*) FROM Users
19 </select>
20 </mapper>
不想学好基础的程序员不是好的程序员。
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