SpringBoot+Spring JdbcTemplate后端开发实例（连接mysql数据库）

项目整体目录如下：

user实体类

package com.example.system.entity;
import java.util.Date;
/**
 * 用户信息对象
 * @author xutao
 * 创建时间：2020-12-8 上午13:59:23
 */public class sysUser{
    public int id;//id
 public String username;//用户名
 public String loginname;//登录账号
 public String password;//密码
 public int areaid;//区域编码
 public int orgid;//机构id
 public String sex;//性别
 public String email;//邮箱
 public int phone;//手机号码
 public String ipaddress;//IP地址
 public int errorcount;//错误计数
 public Date lastlogintime;//上次登录时间
 public Date passwdinvaltime;//密码失效时间
 public Date locktime;//锁定时间
 public int delflag;//删除标识
 public Date createtime;//创建时间
 public String createuser;//创建用户
 public Date updatetime;//更新时间
 public String updateuser;//更新用户
 public int groupid;//组别id
 public int roleid;//角色id
 public int getId() {
        return id;
    }
    public void setId(int id) {
        this.id = id;
    }
    public String getUsername() {
        return username;
    }
    public void setUsername(String username) {
        this.username = username;
    }
    public String getLoginname() {
        return loginname;
    }
    public void setLoginname(String loginname) {
        this.loginname = loginname;
    }
    public String getPassword() {
        return password;
    }
    public void setPassword(String password) {
        this.password = password;
    }
    public int getAreaid() {
        return areaid;
    }
    public void setAreaid(int areaid) {
        this.areaid = areaid;
    }
    public int getOrgid() {
        return orgid;
    }
    public void setOrgid(int orgid) {
        this.orgid = orgid;
    }
    public String getSex() {
        return sex;
    }
    public void setSex(String sex) {
        this.sex = sex;
    }
    public String getEmail() {
        return email;
    }
    public void setEmail(String email) {
        this.email = email;
    }
    public int getPhone() {
        return phone;
    }
    public void setPhone(int phone) {
        this.phone = phone;
    }
    public String getIpaddress() {
        return ipaddress;
    }
    public void setIpaddress(String ipaddress) {
        this.ipaddress = ipaddress;
    }
    public int getErrorcount() {
        return errorcount;
    }
    public void setErrorcount(int errorcount) {
        this.errorcount = errorcount;
    }
    public Date getLastlogintime() {
        return lastlogintime;
    }
    public void setLastlogintime(Date lastlogintime) {
        this.lastlogintime = lastlogintime;
    }
    public Date getPasswdinvaltime() {
        return passwdinvaltime;
    }
    public void setPasswdinvaltime(Date passwdinvaltime) {
        this.passwdinvaltime = passwdinvaltime;
    }
    public Date getLocktime() {
        return locktime;
    }
    public void setLocktime(Date locktime) {
        this.locktime = locktime;
    }
    public int getDelflag() {
        return delflag;
    }
    public void setDelflag(int delflag) {
        this.delflag = delflag;
    }
    public Date getCreatetime() {
        return createtime;
    }
    public void setCreatetime(Date createtime) {
        this.createtime = createtime;
    }
    public String getCreateuser() {
        return createuser;
    }
    public void setCreateuser(String createuser) {
        this.createuser = createuser;
    }
    public Date getUpdatetime() {
        return updatetime;
    }
    public void setUpdatetime(Date updatetime) {
        this.updatetime = updatetime;
    }
    public String getUpdateuser() {
        return updateuser;
    }
    public void setUpdateuser(String updateuser) {
        this.updateuser = updateuser;
    }
    public int getGroupid() {
        return groupid;
    }
    public void setGroupid(int groupid) {
        this.groupid = groupid;
    }
    public int getRoleid() {
        return roleid;
    }
    public void setRoleid(int roleid) {
        this.roleid = roleid;
    }
}

持久层接口dao

package com.example.system.dao;
import com.example.system.entity.sysUser;
/**
 * 登录功能dao接口
 * @author lmwang
 * 创建时间：2020-12-9 下午16:53:20
 */
public interface loginDao {
    //登录验证账号密码
 public Object login(String loginName,String password);
    //首次登录强制修改密码/重置密码（管理员权限）
 public void updatePd(int id,String password);
    //登录成功后获取用户唯一id
 public Object queryById(String loginName);
    //通过唯一id获取用户对象
 public sysUser userById(int id);
    //用户修改个人信息
 public void updateSysUser(sysUser user);
}

dao映射层daoimpl，继承dao接口

package com.example.system.dao.impl;
import com.example.system.dao.loginDao;
import com.example.system.entity.sysUser;
import com.example.system.util.JdbcDaoSupport4mysql;
import com.example.system.util.MysqlDb;
import org.springframework.dao.DataAccessException;
import org.springframework.jdbc.core.ResultSetExtractor;
import org.springframework.stereotype.Repository;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.ArrayList;
@MysqlDb
@Repository
public class loginDaoImpl extends JdbcDaoSupport4mysql implements loginDao {
    @Override
 public Object login(String loginName, String password) {
        String sql="select password from sys_user where login_name='"+loginName+"'";
        ArrayList