jwt - Spring boot and JWTToken and how to authenticate the User -

i learning how implement jwt token generation spring boot restful controller , following article on https://auth0.com/blog/securing-spring-boot-with-jwts/

by following article able generate jwt token , able access /users. in article author defaulted user name , password below:

public class websecurityconfig extends websecurityconfigureradapter {

@override protected void configure(httpsecurity http) throws exception {     // disable caching     http.headers().cachecontrol();      http.csrf().disable() // disable csrf our requests.         .authorizerequests()         .antmatchers("/").permitall()         .antmatchers(httpmethod.post, "/login").permitall()         .anyrequest().authenticated()         .and()         // filter api/login requests         .addfilterbefore(new jwtloginfilter("/login", authenticationmanager()), usernamepasswordauthenticationfilter.class)         // , filter other requests check presence of jwt in header         .addfilterbefore(new jwtauthenticationfilter(), usernamepasswordauthenticationfilter.class); }  @override protected void configure(authenticationmanagerbuilder auth) throws exception {     // create default account     auth.inmemoryauthentication()         .withuser("admin")         .password("password")         .roles("admin"); } 

}

i trying understand how authenticate credential s of user hitting data base or dao layer please me wrote mean in while file { tokenauthenticationservice ,jwtloginfilter, jwtauthenticationfilter }and mehod () dao layer code