@Override
    public String findUsername(final PasswordManagementQuery query) {
        try {
            return transactionTemplate.execute(action ->
                jdbcTemplate.queryForObject(casProperties.getAuthn().getPm().getJdbc().getSqlFindUser(), String.class, query.getEmail()));
        } catch (final EmptyResultDataAccessException e) {
            LOGGER.debug("Email [{}] not found when searching for user", query.getEmail());
            return null;
        }
    }
This is {@link JdbcPasswordManagementService}.

@author Misagh Moayyed
@since 5.1.0
support/cas-server-support-pm-jdbc/src/main/java/org/apereo/cas/pm/jdbc/JdbcPasswordManagementService.java