Spring Security: In-Memory Authentication example

Below is an example configuration using the WebSecurityConfigurerAdapter that configures an in-memory user store with a single user:

@Configuration

public class SecurityConfiguration extends WebSecurityConfigurerAdapter {

    @Override

    protected void configure(AuthenticationManagerBuilder auth) throws Exception {

        UserDetails user = User.withDefaultPasswordEncoder()

            .username("user")

            .password("password")

            .roles("USER")

            .build();

        auth.inMemoryAuthentication()

            .withUser(user);

    }

}

The recommended way of doing this is registering an InMemoryUserDetailsManager bean:

@Configuration

public class SecurityConfiguration {

    @Bean

    public InMemoryUserDetailsManager userDetailsService() {

        UserDetails user = User.withDefaultPasswordEncoder()

            .username("user")

            .password("password")

            .roles("USER")

            .build();

        return new InMemoryUserDetailsManager(user);

    }

}

Note: In these examples, we use the method User.withDefaultPasswordEncoder() for readability. It is not intended for production and instead we recommend hashing your passwords externally. One way to do that is to use the Spring Boot CLI as described in the reference documentation.