后台登录功能开发

需求分析：

点击登录按钮时，页面发送请求并提交参数(username和password)

请求发送--》controller--》Service--》Mapper--》DB

员工表employee。

代码开发：

//mapper接口，持久层与数据库进行交互
package com.itheima.mapper;

import com.baomidou.mybatisplus.core.mapper.BaseMapper;
import com.itheima.entity.Employee;
import org.apache.ibatis.annotations.Mapper;

@Mapper
public interface EmployeeMapper extends BaseMapper<Employee> {
}

//service接口，继承IService
package com.itheima.service;

import com.baomidou.mybatisplus.extension.service.IService;
import com.itheima.entity.Employee;

public interface EmployeeService extends IService<Employee> {
}

//serviceimpl类实现service接口
package com.itheima.service.impl;

import com.baomidou.mybatisplus.extension.service.impl.ServiceImpl;
import com.itheima.entity.Employee;
import com.itheima.mapper.EmployeeMapper;
import com.itheima.service.EmployeeService;
import org.springframework.stereotype.Service;

@Service
public class EmployeeServiceImpl extends ServiceImpl<EmployeeMapper, Employee> implements EmployeeService{
}

返回结果类：通用结果类，服务端响应的所有结果最终都会包装成此种类型返回给前端页面

package com.itheima.common;

import lombok.Data;
import java.util.HashMap;
import java.util.Map;

/**
 * 通用返回结果，服务器端响应的数据最终都会封装成此对象
 * @param <T>
 */
@Data
public class R<T> {

    private Integer code; //编码：1成功，0和其它数字为失败

    private String msg; //错误信息

    private T data; //数据

    private Map map = new HashMap(); //动态数据

    //<T>表示该方法是个泛型方法， R<T>是返回值

    public static <T> R<T> success(T object) {
        R<T> r = new R<T>();
        r.data = object;
        r.code = 1;
        return r;
    }

    public static <T> R<T> error(String msg) {
        R r = new R();
        r.msg = msg;
        r.code = 0;
        return r;
    }

    public R<T> add(String key, Object value) {
        this.map.put(key, value);
        return this;
    }

}

controller.EmployeeController控制器提供服务

package com.itheima.controller;

import com.baomidou.mybatisplus.core.conditions.query.LambdaQueryWrapper;
import com.itheima.common.R;
import com.itheima.entity.Employee;
import com.itheima.service.EmployeeService;
import lombok.extern.slf4j.Slf4j;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.util.DigestUtils;
import org.springframework.web.bind.annotation.PostMapping;
import org.springframework.web.bind.annotation.RequestBody;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpSession;

@Slf4j
@RestController
@RequestMapping("/employee")
public class EmployeeController {

    @Autowired
    private EmployeeService employeeService;

    //传过来的json的key需要和employee实体类中的属性名相同才能封装
    /**
     * 员工登录
     *
     */
    @PostMapping("/login")
    public R<Employee> login(HttpServletRequest request, @RequestBody Employee employee){

        String password = employee.getPassword();
        //1、将页面提交的密码password进行md5加密
        password = DigestUtils.md5DigestAsHex(password.getBytes());
        //2、根据页面提交的用户名username查询数据库
        LambdaQueryWrapper<Employee> queryWrapper = new LambdaQueryWrapper<Employee>();
        queryWrapper.eq(Employee::getUsername, employee.getUsername());
        Employee emp = employeeService.getOne(queryWrapper);
        //3、如果没有查询到则返回登录失败结果
        if(emp==null){
           return R.error("登录失败");
        }
        //4、密码对比，如果不一致则返回登录失败结果
        if(!emp.getPassword().equals(password)){
            return R.error("登录失败");
        }
        //5、查看员工状态，如果为已禁用状态，则返回员工已禁用结果
        if(emp.getStatus()==0){
            return R.error("账号已禁用");
        }
        //6、登录成功，将员工id存入Session并返回登录成功结果
        HttpSession session = request.getSession();
        session.setAttribute("employee", emp.getId());
        return R.success(emp);
    }


}