一 .使用原生分页器的实体类

        1.1 java代码部分

                方法多  不易书写

package cn.bdqn.entity;

public class Page {
    private Integer pageIndex;//页码

    private Integer pageSize;//页大小  显示多少行数据

    private Integer totalCounts;//数据的总行数

    private Integer totalPages;//总页数

    private Integer startRows;//起始行

    private String sname="";
    private String grade="";

    private String sex="";

    public Page() {
    }

    public Page(Integer pageIndex) {
        this(pageIndex, 7);
    }

    public Page(Integer pageIndex, Integer pageSize, Integer totalCounts, Integer totalPages, Integer startRows, String snane, String sex, String grade) {
        this.pageIndex = pageIndex;
        this.pageSize = pageSize;
        this.totalCounts = totalCounts;
        this.totalPages = totalPages;
        this.startRows = startRows;
        this.sname = sname;
        this.sex = sex;
        this.grade = grade;
    }

    public Page(Integer pageIndex, Integer pageSize) {
        this.pageIndex = pageIndex;
        this.pageSize = pageSize;
        this.setStartRows((pageIndex - 1) * pageSize);
    }

    public Integer getPageIndex() {
        return pageIndex;
    }

    public void setPageIndex(Integer pageIndex) {
        this.pageIndex = pageIndex;
    }

    public Integer getPageSize() {
        return pageSize;
    }

    public void setPageSize(Integer pageSize) {
        this.pageSize = pageSize;
    }

    public Integer getTotalCounts(int count) {
        return totalCounts;
    }

    public void setTotalCounts(Integer totalCounts) {
        this.totalCounts = totalCounts;

        this.setTotalPages(totalCounts % pageSize == 0 ? totalCounts / pageSize : totalCounts / pageSize + 1);
    }

    public Integer getTotalPages() {
        return totalPages;
    }

    public void setTotalPages(Integer totalPages) {
        this.totalPages = totalPages;
    }

    public Integer getStartRows() {
        return startRows;
    }

    public void setStartRows(Integer startRows) {
        this.startRows = startRows;
    }

//    public int getPageNum() {
//        return pageNum;
//    }
//


    public String getSname() {
        return sname;
    }

    public void setSname(String sname) {
        this.sname = sname;
    }

    public String getGrade() {
        return grade;
    }

    public void setGrade(String grade) {
        this.grade = grade;
    }


    public String getSex() {
        return sex;
    }

    public void setSex(String grade) {
        this.sex = sex;
    }
//    @Override
//    public String toString() {
//        return "Page{" +
//                "pageIndex=" + pageIndex +
//                ", pageSize=" + pageSize +
//                ", totalCounts=" + totalCounts +
//                ", totalPages=" + totalPages +
//                ", startRows=" + startRows +
//                '}';
//    }


    @Override
    public String toString() {
        return "Page{" +
                "pageIndex=" + pageIndex +
                ", pageSize=" + pageSize +
                ", totalCounts=" + totalCounts +
                ", totalPages=" + totalPages +
                ", startRows=" + startRows +
                ", sname='" + sname + '\'' +
                ", sex='" + sex + '\'' +
                ", grade='" + grade + '\'' +
                '}';
    }
}

        1.2 在动态jsp页面中    用forEach  书写

<div class="a-run">
    <a href="<c:url context='${pageContext.request.contextPath}' value='/ServletScoreShow?pageIndex=1'/>">首页</a>

    <c:if test="${page.pageIndex > 1}">
        <a href="<c:url context='${pageContext.request.contextPath}' value='/ServletScoreShow?pageIndex=${page.pageIndex - 1}' />">上一页</a>
    </c:if>
    <c:if test="${page.pageIndex == 1}">
        <a>上一页</a>
    </c:if>


    <c:if test="${page.pageIndex < page.totalPages}">
        <a href="<c:url context='${pageContext.request.contextPath}' value='/ServletScoreShow?pageIndex=${page.pageIndex + 1}'/>">下一页</a>
    </c:if>
    <c:if test="${page.pageIndex == page.totalPages}">
        <a>下一页</a>
    </c:if>

    <a href="<c:url context='${pageContext.request.contextPath}' value='/ServletScoreShow?pageIndex=${page.totalPages}'/>">尾页</a>

</div>

 二 . 使用mybatis  分页

             2.1.1  在pom.xml文件中引入依赖

       

 <!--引入分页插件-->
  <dependency>
    <groupId>com.github.pagehelper</groupId>
    <artifactId>pagehelper</artifactId>
    <version>5.3.2</version>
  </dependency>
</dependencies>

                2.1.2  在mybatis.xml中   设定标签（注意标签书写顺序）

<!--配置mybatis分页插件-->
<plugins>
    <plugin interceptor="com.github.pagehelper.PageInterceptor"></plugin>
</plugins>

三 . 测试类代码

package cn.sy;

import cn.sy.entity.User;
import cn.sy.mapper.UserMapper;
import com.github.pagehelper.PageHelper;
import com.github.pagehelper.PageInfo;
import org.apache.ibatis.io.Resources;
import org.apache.ibatis.session.SqlSession;
import org.apache.ibatis.session.SqlSessionFactory;
import org.apache.ibatis.session.SqlSessionFactoryBuilder;
import org.junit.Before;
import org.junit.Test;

import java.io.IOException;
import java.io.InputStream;
import java.util.List;

public class TestPageHelper {

    SqlSessionFactory factory = null;

    @Before
    public void init() {

        try {
            InputStream resourceAsStream = Resources.getResourceAsStream("config/mybatis-config.xml");
            factory = new SqlSessionFactoryBuilder().build(resourceAsStream);
        } catch (IOException e) {
            e.printStackTrace();
        }
    }

    @Test
    public void test(){
        SqlSession sqlSession = factory.openSession(true);
        UserMapper mapper = sqlSession.getMapper(UserMapper.class);

        //pageNum : 分的页数  pageSize： 每页显示的记录数
        PageHelper.startPage(3,3);
        List<User> users = mapper.selectList();

        for (User user : users) {
            System.out.println("user = " + user);
        }

        // 创建分页信息对象  获取更多的分页信息
        PageInfo<User> userPageInfo = new PageInfo<>(users);

        // 获取分页的详细信息

        List<User> list = userPageInfo.getList();

        System.out.println("list = " + list);

        long total = userPageInfo.getTotal();

        System.out.println("total = " + total);

        System.out.println("*********************");

        System.out.println("userPageInfo = " + userPageInfo);


    }
}