Multiple Authentication Provider Security Config #spring-security

SecurityConfig.java

@Configuration
@EnableWebSecurity()
static class SecurityConfig {
    public static class CustomAuthenticationProvider implements AuthenticationProvider {
        private final String username;
        private final String password;
        private final String role;

        CustomAuthenticationProvider(String username, String password, String role) {
            this.username = username;
            this.password = password;
            this.role = role;
        }

        @Override
        public Authentication authenticate(Authentication auth)
                throws AuthenticationException {
            String u = auth.getName();
            String p = auth.getCredentials().toString();

            if (username.equals(u) && password.equals(p)) {
                return new UsernamePasswordAuthenticationToken
                        (username, password, Collections.singletonList(new SimpleGrantedAuthority(role)));
            } else {
                throw new
                        BadCredentialsException("External system authentication failed");
            }
        }

        @Override
        public boolean supports(Class<?> auth) {
            return auth.equals(UsernamePasswordAuthenticationToken.class);
        }
    }

    @Bean
    public SecurityFilterChain securityFilterChain(HttpSecurity httpSecurity) throws Exception {
        AuthenticationManagerBuilder authenticationManagerBuilder =
                httpSecurity.getSharedObject(AuthenticationManagerBuilder.class);

        authenticationManagerBuilder.authenticationProvider(new CustomAuthenticationProvider("user", "password", "USER"));
        authenticationManagerBuilder.authenticationProvider(new CustomAuthenticationProvider("user1", "password", "USER"));
        authenticationManagerBuilder.authenticationProvider(new CustomAuthenticationProvider("admin", "password", "ADMIN"));
        authenticationManagerBuilder.authenticationProvider(new CustomAuthenticationProvider("admin1", "password", "ADMIN"));

        httpSecurity.authenticationManager(authenticationManagerBuilder.build());

        httpSecurity
                .authorizeHttpRequests(auth -> {
                    auth.requestMatchers(EndpointRequest.toAnyEndpoint()).permitAll();
                    auth.anyRequest().fullyAuthenticated();
                });
        httpSecurity.logout(new LogoutCustomizer());
        httpSecurity.formLogin(withDefaults());
        return httpSecurity.build();
    }

    @Bean
    public PasswordEncoder passwordEncoder() {
        return NoOpPasswordEncoder.getInstance();
    }
}