Java | 分页功能 JSP+Java

思路：建一个分页的实体类，包含属性：总数据数，总页数，满足条件的List集合，当前页，每页显示的条数。封装对象，通过servlet转发到前端jsp界面，使用JSTL渲染界面数据。

效果

前端

<nav aria-label="Page navigation">
        <ul class="pagination">
            <c:if test="${pageBean.currentPage==1}">
            <li class="disabled">
                </c:if>
                <c:if test="${pageBean.currentPage!=1}">
            <li>
                </c:if>
                <a href="${pageContext.request.contextPath}/bookInfoList?currentPage=${pageBean.currentPage-1}"
                   aria-label="Previous">
                    <span aria-hidden="true">&laquo;</span>
                </a>
            </li>
            <c:if test="${pageBean.currentPage==1}">
                <li><a style="background: #2aabd2" href="${pageContext.request.contextPath}/bookInfoList?currentPage=1">1</a>
                </li>
            </c:if>
            <c:if test="${pageBean.currentPage!=1}">
                <li><a href="${pageContext.request.contextPath}/bookInfoList?currentPage=1">1</a></li>
            </c:if>
            <c:forEach begin="2" end="${pageBean.totalPage}" var="i">
                <c:if test="${pageBean.currentPage==i}">
                    <li><a style="background: #2aabd2"
                           href="${pageContext.request.contextPath}/bookInfoList?currentPage=${i}">${i}</a></li>
                </c:if>
                <c:if test="${pageBean.currentPage!=i}">
                    <li><a href="${pageContext.request.contextPath}/bookInfoList?currentPage=${i}">${i}</a></li>
                </c:if>
            </c:forEach>
            <c:if test="${pageBean.currentPage!=pageBean.totalPage}">
            <li>
                </c:if>
                <c:if test="${pageBean.currentPage==pageBean.totalPage}">
            <li class="disabled">
                </c:if>
                <a href="${pageContext.request.contextPath}/bookInfoList?currentPage=${pageBean.currentPage+1}"
                   aria-label="Next">
                    <span aria-hidden="true">&raquo;</span>
                </a>
            </li>
            <strong>当前一共有${pageBean.totalCount}条数据，共${pageBean.totalPage}页</strong>
        </ul>
    </nav>

servlet

protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        req.setCharacterEncoding("utf-8");
        resp.setContentType("text/html;charset=UTF-8");
        String currentPage = req.getParameter("currentPage");
        String rows = req.getParameter("rows");
        if (currentPage == null || "".equals(currentPage)) {
            currentPage = "1";
        }
        if (Integer.parseInt(currentPage) <= 0) {
            currentPage = "1";
        }
        if (rows == null || "".equals(rows)) {
            rows = "4";
        }
        PageBean<BookInfo> PageBean = bookInfoService.BookListByPage(currentPage, rows);
        req.setAttribute("pageBean", PageBean);
        req.getRequestDispatcher("bookinfolist.jsp").forward(req, resp);
    }

PageBean实体类

package com.library.pojo;

import lombok.AllArgsConstructor;
import lombok.Data;
import lombok.NoArgsConstructor;

import java.util.List;

@Data
@AllArgsConstructor
@NoArgsConstructor
public class PageBean<T> {
    private int totalCount;//总共数据的条数
    private int totalPage;//总共数据的页数
    private List<T> list;//每页数据的list集合
    private int currentPage;//当前页码
    private int rows;//每页显示的条数
}

service层

public PageBean<BookInfo> BookListByPage(String _currentPage, String _rows) {
        int currentPage = Integer.parseInt(_currentPage);
        int rows = Integer.parseInt(_rows);
        PageBean<BookInfo> pageBean = new PageBean<BookInfo>();
        pageBean.setRows(rows);
        pageBean.setCurrentPage(currentPage);
        int totalCount = bookInfoDao.findTotalCount();
        pageBean.setTotalCount(totalCount);
        int totalPage = (totalCount % rows) == 0 ? totalCount / rows : (totalCount / rows) + 1;
        pageBean.setTotalPage(totalPage);
        if (currentPage >= pageBean.getTotalPage()) {
            currentPage = pageBean.getTotalPage();
        }
        pageBean.setCurrentPage(currentPage);
        List<BookInfo> list = bookInfoDao.findList((currentPage - 1) * rows, rows);
        pageBean.setList(list);
        return pageBean;
    }

dao层

@Override
public int findTotalCount() {
    String sql = "select * from book_info";
    return Utils.executeQuery(sql, null, BookInfo.class).size();
}

@Override
public List<BookInfo> findList(int i, int rows) {
    String sql = "select * from book_info limit ?,?";
    Object[] params = {i, rows};
    return Utils.executeQuery(sql, params, BookInfo.class);
}