2. login and exit function development

Login and exit function development

1、 Login function development

1.1、 establish MVC structure

Landing site ：http://localhost:8080/backend/page/login/login.html

1、 Create an employee entity class Employee

package com.itheima.reggie.entity;

import com.baomidou.mybatisplus.annotation.FieldFill;
import com.baomidou.mybatisplus.annotation.TableField;
import lombok.Data;

import java.io.Serializable;
import java.time.LocalDateTime;

/** * @Author: xjhqre * @DateTime: 2022/6/15 16:45 */
@Data
public class Employee implements Serializable {
    

    private static final long serialVersionUID = 1L;

    private Long id;

    private String username;

    private String name;

    private String password;

    private String phone;

    private String sex;

    private String idNumber; //  Id card number 

    private Integer status;

    private LocalDateTime createTime;

    private LocalDateTime updateTime;

    @TableField(fill = FieldFill.INSERT)
    private Long createUser;

    @TableField(fill = FieldFill.INSERT_UPDATE)
    private Long updateUser;

}

2、 establish MVC Catalog ：controller、service、service.impl、mapper

3、 establish EmployeeMapper

package com.itheima.reggie.mapper;

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

/** * @Author: xjhqre * @DateTime: 2022/6/15 16:47 */
@Mapper
public interface EmployeeMapper extends BaseMapper<Employee> {
    
}

4、 establish EmployeeService

package com.itheima.reggie.service;

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

/** * @Author: xjhqre * @DateTime: 2022/6/15 16:48 */
public interface EmployeeService extends IService<Employee> {
    
}

5、 establish EmployeeServiceImpl

package com.itheima.reggie.service.impl;

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

/** * @Author: xjhqre * @DateTime: 2022/6/15 16:48 */
@Service
public class EmployeeServiceImpl extends ServiceImpl<EmployeeMapper, Employee> implements EmployeeService {
    
}

6、 establish EmployeeController

package com.itheima.reggie.controller;

import com.itheima.reggie.service.EmployeeService;
import lombok.extern.slf4j.Slf4j;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;

/** * @Author: xjhqre * @DateTime: 2022/6/15 16:50 */
@Slf4j
@RestController
@RequestMapping("/employee")
public class EmployeeController {
    

    @Autowired
    private EmployeeService employeeService;
}

1.2、 Create a return value class R

establish common Catalog , Create... In this directory R

Used to return information to the front end , Encapsulate all the information you need to transfer as R object

package com.itheima.reggie.common;

import lombok.Data;

import java.util.HashMap;
import java.util.Map;

/** * @Author: xjhqre * @DateTime: 2022/6/15 17:04 */
@Data
public class R<T> {
    

    private Integer code; // code ：1 success ,0 And other numbers are failures 

    private String msg; // error message 

    private T data; // data 

    private Map map = new HashMap(); // Dynamic data 

    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;
    }

}

1.3、 stay controller Create login method in

establish login Method , route ：com/itheima/reggie/controller/EmployeeController.java

/** *  Employee login  * @param request * @param employee * @return */
@PostMapping("/login")
public R<Employee> login(HttpServletRequest request, @RequestBody Employee employee) {
    
    // 1.  Submit the password of the page password Conduct md5 Encryption processing , The same string goes through MD5 The encrypted result is the same 
    String password = employee.getPassword();
    password = DigestUtils.md5DigestAsHex(password.getBytes());

    // 2.  According to the user name submitted on the page username Query the database 
    LambdaQueryWrapper<Employee> queryWrapper = new LambdaQueryWrapper<>();
    queryWrapper.eq(Employee::getUsername, employee.getUsername());
    Employee emp = employeeService.getOne(queryWrapper); // username Field uniqueness 

    // 3.  If there is no query, the login failure result will be returned 
    if (emp == null) {
    
        return R.error(" Login failed ");
    }

    // 4.  Password comparison . If not, the login failure result will be returned 
    if (!emp.getPassword().equals(password)) {
     //  If the password in the database is different from the passed in parameter password 
        return R.error(" Login failed ");
    }

    // 5.  View employee status , If it is disabled , The disabled employee result is returned 
    if (emp.getStatus() == 0) {
    
        return R.error(" Account has been disabled ");
    }

    // 6.  Login successful , Staff id Deposit in session And return the login success result 
    request.getSession().setAttribute("employee", emp.getId());
    return R.success(emp); //  Look up the data from the database emp Deposit in R in 
}

1.4、 Debug timeout resolution

modify request.js In the file timeout Parameters , route ：backend/js/request.js

2、 Exit function development

After clicking the exit button , Send request to backend , Back end cleanup session Users in id And back to success

2.1 Create exit method

stay EmployeeController Created in logout Method , route ：com/itheima/reggie/controller/EmployeeController.java

/** *  The employee exits the current account  * @param request * @return */
@PostMapping("/logout")
public R<String> logout(HttpServletRequest request) {
    
    request.getSession().removeAttribute("employee");
    return R.success(" Quit successfully ");
}

3、 Block unlisted users

If the employee is not logged in, it is forbidden to access index home page , Return to the login page .

Implementation method ：

1. Create custom filters LoginCheckFilter
2. Add annotations to the startup class @ServletComponentScan
3. Improve the processing logic of the filter

3.1、 establish Filter

Create directory filter, Create... In this directory LoginCheckFilter class

On the front end request.js The response interceptor in the file is based on res.data.code and res.data.msg Determine whether you need to return to the login page , So if the interceptor in the back end intercepts a request, it needs to write back one R Pass it to the front end for judgment .

package com.itheima.reggie.filter;

import com.alibaba.fastjson.JSON;
import com.itheima.reggie.common.R;
import lombok.extern.slf4j.Slf4j;
import org.springframework.util.AntPathMatcher;

import javax.servlet.*;
import javax.servlet.annotation.WebFilter;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;

/** * @Author: xjhqre * @DateTime: 2022/6/16 20:45 */
@Slf4j
@WebFilter(filterName = "loginCheckFilter", urlPatterns = "/*")
public class LoginCheckFilter implements Filter {
    
    //  Path matcher , Support for wildcards 
    public static final AntPathMatcher PATH_MATCHER = new AntPathMatcher();

    @Override
    public void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain filterChain) throws IOException, ServletException {
    
        HttpServletRequest request = (HttpServletRequest) servletRequest;
        HttpServletResponse response = (HttpServletResponse) servletResponse;

        // 1.  Get this request's URI
        String requestURI = request.getRequestURI();
        log.info(" Intercept request ：{}", requestURI);
        String [] urls = new String[]{
     //  Define the request path that does not need to be processed 
                "/employee/login",
                "/employee/logout",
                "/backend/**",
                "/front/**"
        };

        // 2.  Judge whether this request needs to be processed 
        boolean check = check(urls, requestURI);

        // 3.  If it doesn't need to be dealt with , Then direct release 
        if (check) {
    
            log.info(" This request {} No need to deal with ：", requestURI);
            filterChain.doFilter(request, response);
            return;
        }

        // 4.  Judge whether you have logged in , If you have already logged in, you can release it directly 
        if (request.getSession().getAttribute("employee") != null) {
    
            log.info(" The user has logged in , user id by ：{}", request.getSession().getAttribute("employee"));
            filterChain.doFilter(request, response);
            return;
        }

        // 5.  If you are not logged in, you will directly return the result of not logging in 
        log.info(" The user is not logged in ");
        response.getWriter().write(JSON.toJSONString(R.error("NOTLOGIN")));
    }

    /** *  Match path , Check whether this request needs to be released  * @param urls * @param requestURI * @return */
    public boolean check(String[] urls, String requestURI) {
    
        for (String url : urls) {
    
            boolean match = PATH_MATCHER.match(url, requestURI);
            if (match) {
    
                return true;
            }
        }
        return false;
    }
}

3.2、 Add... In the main startup class @ServletComponentScan

3.3、 Test the interceptor

Home address ：http://localhost:8080/backend/index.html

Login address ：http://localhost:8080/backend/page/login/login.html