How do I implement security in spring boot?

dependencies {
    ...
    compile("org.springframework.boot:spring-boot-starter-security")
    ...
}

import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.security.config.annotation.web.builders.HttpSecurity;
import org.springframework.security.config.annotation.web.configuration.EnableWebSecurity;
import org.springframework.security.config.annotation.web.configuration.WebSecurityConfigurerAdapter;
import org.springframework.security.core.userdetails.User;
import org.springframework.security.core.userdetails.UserDetails;
import org.springframework.security.core.userdetails.UserDetailsService;
import org.springframework.security.provisioning.InMemoryUserDetailsManager;

@Configuration
@EnableWebSecurity
public class WebSecurityConfig extends WebSecurityConfigurerAdapter {
  @Override
  protected void configure(HttpSecurity http) throws Exception {
    http
      .authorizeRequests()
        .antMatchers("/", "/home").permitAll()
        .anyRequest().authenticated()
        .and()
      .formLogin()
        .loginPage("/login")
        .permitAll()
        .and()
      .logout()
        .permitAll();
  }

  @Bean
  @Override
  public UserDetailsService userDetailsService() {
    UserDetails user =
       User.withDefaultPasswordEncoder()
        .username("user")
        .password("password")
        .roles("USER")
        .build();

    return new InMemoryUserDetailsManager(user);
  }
}