分页查询

1 PageBean

package com.li.domain;

import java.util.List;

/**
 * @Program: exam
 * @ClassName: PageBean
 * @Description: 分页查询
 * @Author: li
 * @Create: 2019-07-23 19:25
 */
public class PageBean<T> {
    private Integer currentPage;
    private Integer pageSize;
    private Integer totalPage;
    private Integer totalData;
    private List<T> list;

    public PageBean(Integer currentPage, Integer pageSize, Integer totalData, List<T> list) {
        this.currentPage = currentPage;
        this.pageSize = pageSize;
        this.totalPage = totalData % pageSize == 0 ? totalData / pageSize : totalData / pageSize + 1;
        this.totalData = totalData;
        this.list = list;
    }

    public PageBean() {
    }

    @Override
    public String toString() {
        return "PageBean{" +
                "currentPage=" + currentPage +
                ", pageSize=" + pageSize +
                ", totalPage=" + totalPage +
                ", totalData=" + totalData +
                ", list=" + list +
                '}';
    }

    public Integer getCurrentPage() {
        return currentPage;
    }

    public void setCurrentPage(Integer currentPage) {
        this.currentPage = currentPage;
    }

    public Integer getPageSize() {
        return pageSize;
    }

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

    public Integer getTotalPage() {
        return totalPage;
    }

    public void setTotalPage(Integer totalPage) {
        this.totalPage = totalPage;
    }

    public Integer getTotalData() {
        return totalData;
    }

    public void setTotalData(Integer totalData) {
        this.totalData = totalData;
    }

    public List<T> getList() {
        return list;
    }

    public void setList(List<T> list) {
        this.list = list;
    }
}

2 DAO

返回模糊分页数据
@Override
    public List<User> pageUser(int pageStart, int pageSize, Map<String, String[]> map) {
        StringBuilder sql = new StringBuilder();
        List<Object> list = new ArrayList<>();
        sql.append("select * from user where 1 = 1");

        Set<String> sets = map.keySet();

        for (String set : sets) {
            if ("".equals(map.get(set)[0]) || "".equals(map.get(set)[0])) {
                continue;
            } else if ("currentPage".equals(set) || "pageSize".equals(set)) {
                continue;
            } else {
                sql.append(" and " + set + " like ?");
                list.add("%" + map.get(set)[0] + "%");
            }
        }

        sql.append(" limit ?,?");
        list.add(pageStart);
        list.add(pageSize);

        return jt.query(sql.toString(), new BeanPropertyRowMapper<User>(User.class), list.toArray());
    }

返回模糊查询的总数据量
    @Override
    public int totalData(Map<String, String[]> map) {
        StringBuilder sql = new StringBuilder();
        List<Object> list = new ArrayList<>();
        sql.append("select count(1) from user where 1 = 1");

        Set<String> sets = map.keySet();

        for (String set : sets) {
            if ("".equals(map.get(set)[0]) || "".equals(map.get(set)[0])) {
                continue;
            } else if ("currentPage".equals(set) || "pageSize".equals(set)) {
                continue;
            } else {
                sql.append(" and " + set + " like ?");
                list.add("%" + map.get(set)[0] + "%");
            }
        }

        return jt.queryForObject(sql.toString(), Integer.class, list.toArray());
    }

3 services

返回一个pageBean
@Override
    public PageBean<User> pageUser(String _pageStart, String _pageSize, Map<String, String[]> map) {
        int pageStart = Integer.parseInt(_pageStart);
        int pageSize = Integer.parseInt(_pageSize);

        List<User> users = dao.pageUser((pageStart - 1) * pageSize, pageSize, map);
        int totalData = dao.totalData(map);
        return new PageBean<User>(pageStart, pageSize, totalData, users);
    }

4 servlet

/**
 * @Program: exam
 * @ClassName: PageUserServlet
 * @Description: 分页加模糊查询User
 * @Author: li
 * @Create: 2019-07-23 19:29
 */
@WebServlet("/PageUserServlet")
public class PageUserServlet extends HttpServlet {
    @Override
    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        doGet(request, response);
    }

    @Override
    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        Map<String, String[]> map = request.getParameterMap();

        String currentPage = request.getParameter("currentPage");
        String pageSize = request.getParameter("pageSize");
        IUserServices services = new UserServicesImpl();

        if(currentPage == null){
            currentPage = "1";
        }

        if(pageSize == null){
            pageSize = "5";
        }

        PageBean<User> pageUser = services.pageUser(currentPage, pageSize,map);

        request.setAttribute("pu",pageUser);
        request.setAttribute("mp",map);
        request.getRequestDispatcher("member-list.jsp").forward(request, response);
    }
}

5 jsp

                        <c:forEach var="user" items="${pu.list}" varStatus="s">
                            <tr>
                                <td>
                                    <input type="checkbox" name="id" value="${user.email}" lay-skin="primary">
                                </td>
                                <td>${s.index + 1}</td>
                                <td>${user.email}</td>
                                <td>${user.username}</td>
                                <td>${user.sex}</td>
                                <td>${user.tel}</td>
                                <td>${user.address}</td>

                                <c:if test="${user.status == 1}">
                                <td class="td-status">
                                    <span class="layui-btn layui-btn-normal layui-btn-mini">已启用</span>
                                </td>
                                <td class="td-manage">
                                    <a onclick="member_stop(this,'${user.email}')" href="javascript:;"
                                       title="启用">
                                        <i class="layui-icon">&#xe601;</i>
                                    </a>
                                    </c:if>

                                    <c:if test="${user.status == -1}">
                                <td class="td-status">
                                    <span class="layui-btn layui-btn-normal layui-btn-mini layui-btn-disabled">已拉黑</span>
                                </td>
                                <td class="td-manage">
                                    <a onclick="member_stop(this,'${user.email}')" href="javascript:;"
                                       title="拉黑">
                                        <i class="layui-icon">&#xe62f;</i>
                                    </a>
                                    </c:if>



                                    <a title="编辑"
                                       onclick="xadmin.open('编辑','FindUserInfoByEmailServlet?email=${user.email}',600,400)"
                                       href="javascript:;">
                                        <i class="layui-icon">&#xe642;</i>
                                    </a>
                                    <a onclick="xadmin.open('修改密码','member-password.jsp?${user.email}',600,400)"
                                       title="修改密码" href="javascript:;">
                                        <i class="layui-icon">&#xe631;</i>
                                    </a>
                                    <a title="删除" onclick="member_del(this,'${user.email}')" href="javascript:;">
                                        <i class="layui-icon">&#xe640;</i>
                                    </a>
                                </td>
                            </tr>
                        </c:forEach>

页码

                <div class="layui-card-body ">
                    <div class="page">
                        <div>
                            <c:if test="${pu.currentPage != 1}">
                                <a class="prev"
                                   href="PageUserServlet?currentPage=${pu.currentPage-1}&pageSize=5&username=${mp.username[0]}&email=${mp.eamil[0]}&tel=${mp.tel[0]}">&lt;&lt;</a>
                            </c:if>

                            <c:forEach end="${pu.totalPage}" var="cpage" begin="1">
                                <c:if test="${pu.currentPage == cpage}">
                                    <span class="current">${cpage}</span>
                                </c:if>

                                <c:if test="${pu.currentPage != cpage}">
                                    <a class="num"
                                       href="PageUserServlet?currentPage=${cpage}&pageSize=5&username=${mp.username[0]}&email=${mp.eamil[0]}&tel=${mp.tel[0]}">${cpage}</a>
                                </c:if>
                            </c:forEach>

                            <c:if test="${pu.currentPage != pu.totalPage}">
                                <a class="next"
                                   href="PageUserServlet?currentPage=${pu.currentPage+1}&pageSize=5&username=${mp.username[0]}&email=${mp.eamil[0]}&tel=${mp.tel[0]}">&gt;&gt;</a>
                            </c:if>
                        </div>
                    </div>
                </div>