Ruiji takeout project - development of business development function Day2

Operate employees

Catalog

• Perfect login function
• New employees
• Paging query of employee information
• Enable / Disable employee account
• Edit employee information

One 、 Perfect login function

Summary of improving login information ：

1. Problem analysis

• Previously, we have completed the development of employee login function of background system , But there is a problem : If the user does not log in , Directly access the system homepage , You can still access .
• This design is unreasonable , What we want to see is , Only after successful login can you access the page in the system , If you don't log in, jump to the login page .
• that , How should it be realized ? The answer is to use filters or interceptors , In filters or interceptors Judge whether the user has completed login , If you don't log in, jump to the login page .
   

1. Code implementation

Implementation steps ：

• Create custom filters LoginCheckFilter  
• Annotate the startup class @ServletComponentScan
• Improve the processing logic of the filter

1.1 Create custom filters LoginCheckFilter  

You need to add comments on the class of this filter WebFilter(filterName = "loginCheckFilter", urlPatterns = "/*")

filterName Is the filter name ,urlPatterns Is the access path ,/* Indicates access to all / The opening page , This class also needs to implement filter, Then implement filter Methods

package com.itheima.filter;

import lombok.extern.slf4j.Slf4j;

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

/**
 *  Check whether the user has finished logging in 
 */
@Slf4j
@WebFilter(filterName = "loginCheckFilter", urlPatterns = "/*")
public class LoginCheckFilter implements Filter {
    @Override
    public void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain filterChain) throws IOException, ServletException {
        // Strong go 
        HttpServletRequest request = (HttpServletRequest)servletRequest;
        HttpServletResponse response = (HttpServletResponse)servletResponse;
        log.info(" Interceptors intercept requests :{}", request.getRequestURI());
        filterChain.doFilter(request, response);
    }
}

1.2 Annotate the startup class @ServletComponentScan

package com.itheima;

import lombok.extern.slf4j.Slf4j;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.boot.web.servlet.ServletComponentScan;

@Slf4j
@ServletComponentScan
@SpringBootApplication
public class ReggieApplication {
    public static void main(String[] args) {
        SpringApplication.run(ReggieApplication.class);
        log.info(" The project started successfully ...");
    }
}

1.3 Improve the processing logic of the filter

See next section

test

Access on Browser ：http://localhost:8080/backend/index.html , Presentation of the console

  Improve the processing logic of the filter

1. Get this request's URI
2. . Judge whether this request needs to be processed
3. If it doesn't need to be dealt with , Then direct release
4. Determine login status , If you are logged in , Then direct release
5. If you are not logged in, the result of not logging in will be returned

   package com.itheima.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;
   
   /**
    *  Check whether the user has finished logging in 
    */
   @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 {
           // Strong go 
           HttpServletRequest request = (HttpServletRequest)servletRequest;
           HttpServletResponse response = (HttpServletResponse)servletResponse;
   
   //        1. Get this request's URI
           String requestURI = request.getRequestURI();
           String[] urls = new String[]{
                   "/employee/login",
                   "/employee/logout",
                   "/backend/**",
                   "/front/**"
           };
           log.info(" Intercept request ：{}",requestURI);
   //        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 does not need to be processed ",requestURI);
               filterChain.doFilter(request, response);
               return;
           }
   //        4. Determine login status , If you are logged in , Then direct release 
           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;
           }
           log.info(" The user is not logged in ");
   //        5. If you are not logged in, the result of not logging in will be returned 
           response.getWriter().write(JSON.toJSONString(R.error("NOTLOGIN")));
           return;
       }
       /**
        *  Path matching , 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;
       }
   }
   

   Two 、 New employees

• Demand analysis
• Data model
• Code development
• A functional test

Demand analysis ： New employees

 

• We need to pay attention to ,employee The table is right username Field adds a unique constraint , because username Is the login account of the employee , Must be unique
  

• employee In the table status The field has been set to the default value 1, Indicates that the state is normal .

Code development ：

Before developing code , Sort out the execution process of the whole program :

1. Page sending ajax request , The data entered in the new employee page is displayed in json Submit to the server in the form of
2. Server side Controller Receive the data submitted by the page and call Service Save the data
3. Service call Mapper Operating the database , Save the data

  Page sending ajax request , The data entered in the new employee page is displayed in json Submit to the server in the form of

@PostMapping
    public R<String> save(@RequestBody Employee employee){
        log.info(" Information of new employees ：{}",employee.toString());
        return R.success(" Add employee successfully ");
    }

Server side Controller Receive the data submitted by the page and call Service Save the data

 /**
     *  New employee information 
     * @param employee
     * @return
     */
    @PostMapping
    public R<String> save(HttpServletRequest request,@RequestBody Employee employee) {
        log.info(" New employee information ： {}", employee.toString());
        employee.setPassword(DigestUtils.md5DigestAsHex("123456".getBytes()));
        employee.setCreateTime(LocalDateTime.now());
        employee.setUpdateTime(LocalDateTime.now());

        // Forced to long type    Get the current logged in user id
        Long empID = (Long) request.getSession().getAttribute("employee");

        employee.setCreateUser(empID);
        employee.setUpdateUser(empID);

        employeeService.save(employee);
        return R.success(" Add employee successfully ");
    }

Check whether to add new employees to the database ：

We found that the employee information we added has been added to the database

  Add the same... Again username（ Employee account number ）

Something unusual happened , Because it has been said above username（ Employee account number ） The index type of is unique, Therefore, you cannot add the existing username

  Add the same employee and make an exception ：

Global exception handler

There is still a problem with the previous program , That is, when we add new employees, the account number entered already exists , because employee A unique constraint is added to this field in the table , At this point, the program will throw an exception :

java.sql. SQLIntegrityConstraintViolationException: Duplicate entry 'zhangsan’for key 'idx_username

At this time, we need our program to catch exceptions , There are usually two ways of handling :

1. stay Controller Add... To the method try、catch Exception capture
2. Use exception handler for global exception capture ( The second method is recommended )

Use the exception handler to handle exceptions

Method ： stay common It's a bag , establish GlobalExceptionHandler class , And add exceptionHandler Method is used to catch exceptions , And return the result

import lombok.extern.slf4j.Slf4j;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.*;

import java.sql.SQLIntegrityConstraintViolationException;

/**
 *  Global exception handling 
 */
// Intercept controller Add above RestController Class 
@ControllerAdvice(annotations = {RestController.class, Controller.class})
// return JSON
@ResponseBody
@Slf4j
public class globalExceptionHandle {

    /**
     *  Exception handling method 
     * @return
     */
    @ExceptionHandler(SQLIntegrityConstraintViolationException.class)
    public R<String> exceptionHandler(SQLIntegrityConstraintViolationException ex){
        log.error(ex.getMessage());
        if (ex.getMessage().contains("Duplicate entry")){
            String[] split = ex.getMessage().split(" ");
            String msg = split[2] + " Already exists ";
            return R.error(msg);
        }
        return R.error(" Unknown error ");
    }
}

Summary of new employee information ：

summary

1. Define the business requirements according to the product prototype
2. Focus on the analysis of data flow process and data format
3. adopt debug Breakpoint debugging trace program execution process