@Override
    public String getPassword(String username) throws UserNotFoundException,
            UnsupportedOperationException
    {

        if (!supportsPasswordRetrieval()) {
            throw new UnsupportedOperationException();
        }
        if (username.contains("@")) {
            // Check that the specified domain matches the server's domain
            int index = username.indexOf("@");
            String domain = username.substring(index + 1);
            if (domain.equals(XMPPServer.getInstance().getServerInfo().getXMPPDomain())) {
                username = username.substring(0, index);
            } else {
                // Unknown domain.
                throw new UserNotFoundException();
            }
        }
        return getPasswordValue(username);
    }
XMPP disallows some characters in identifiers, requiring them to be escaped.

This implementation assumes that the database returns properly escaped identifiers,
but can apply escaping by setting the value of the 'jdbcAuthProvider.isEscaped'
property to 'false'.

@return 'false' if this implementation needs to escape database content before processing.
xmppserver/src/main/java/org/jivesoftware/openfire/auth/JDBCAuthProvider.java