javaweb-35：smbms用户管理底层实现

思路：

1.导入分页的工具类

package com.gongyi.util;


public class PageSupport {
    //当前页码-来自于用户输入
    private int currentPageNo = 1;
    //总数量（表）
    private int totalCount = 0;
    //页面容量
    private int pageSize = 0;
    //总页数-totalCount/pageSize(+1)
    private int totalPageCount = 1;

    public int getCurrentPageNo() {
        return currentPageNo;
    }

    public void setCurrentPageNo(int currentPageNo) {
        if (currentPageNo > 0) {
            this.currentPageNo = currentPageNo;
        }

    }

    public int getTotalCount() {
        return totalCount;
    }

    //OOP三大特性：封装（属性私有，set/get,在set中限定一些不安全的情况），继承，多态
    public void setTotalCount(int totalCount) {
        if (totalCount > 0) {
            this.totalCount = totalCount;
            //设置总页数
            this.setTotalPageCountByRs();
        }

    }

    public void setTotalPageCountByRs() {
        if (this.totalCount % this.pageSize == 0) {
            this.totalPageCount = this.totalCount / this.pageSize;
        } else if (this.totalCount % this.pageSize == 0) {
            this.totalPageCount = this.totalCount / this.pageSize + 1;
        } else {
            this.totalPageCount = 0;
        }
    }

    public int getPageSize() {
        return pageSize;
    }

    public void setPageSize(int pageSize) {
        if (pageSize > 0) {
            this.pageSize = pageSize;
        }

    }

    public int getTotalPageCount() {
        return totalPageCount;
    }

    public void setTotalPageCount(int totalPageCount) {
        this.totalPageCount = totalPageCount;
    }
}

2.用户列表页面导入

userlist.jsp

1.UserDao

//根据用户名或者角色查询用户总数
int getUserCount(Connection connection, String username, int userRole) throws SQLException;

2.UserDaoImpl

//根据用户名或者角色查询用户总数【最难理解的sql】
@Override
public int getUserCount(Connection connection, String username, int userRole) throws SQLException {
    PreparedStatement pstm = null;
    ResultSet rs = null;
    int count = 0;
    if (connection != null) {
        StringBuffer sql = new StringBuffer();
        sql.append("select count(1) as count from smbms_user u,smbms_role r where u.userRole=r.id");
        ArrayList