Class that get's the username and password and try to open a database connection with this information

UserDatabaseAuthenticationProvider.groovy

class UserDatabaseAuthenticationProvider extends AbstractUserDetailsAuthenticationProvider {

  def dataSource

  @Override
  protected void additionalAuthenticationChecks(UserDetails userDetails,
    UsernamePasswordAuthenticationToken token) throws AuthenticationException {
  }

  @Override
  protected UserDetails retrieveUser(String username, 
    UsernamePasswordAuthenticationToken token) throws AuthenticationException {

    String password = (String) token.getCredentials();
		
    if (!StringUtils.hasText(password)) {
      throw new BadCredentialsException("Please enter password");
    }
		
    List<GrantedAuthority> authorities = new ArrayList<GrantedAuthority>();
		
    try {
      Connection connection = dataSource.getConnection(username, password)
      dataSource.setCredentialsForCurrentThread(username, password)
    }catch(SQLException sql) {
      throw new BadCredentialsException("Invalid username or password!");
    }
    
    return new User(username, password,	true, true, true, true,	authorities);

  }
}