src/main/java/com/authlete/jaxrs/AuthleteApiCaller.java
private BackchannelAuthenticationResponse callBackchannelAuthentication(
            String parameters, String clientId, String clientSecret,
            String clientCertificate, String[] clientCertificatePath)
    {
        if (parameters == null)
        {
            // Authlete returns different error codes for null and an empty string.
            // 'null' is regarded as a caller's error. An empty string is regarded
            // as a client application's error.
            parameters = "";
        }

        // Create a request for Authlete's /api/backchannel/authentication API.
        BackchannelAuthenticationRequest request = new BackchannelAuthenticationRequest()
            .setParameters(parameters)
            .setClientId(clientId)
            .setClientSecret(clientSecret)
            .setClientCertificate(clientCertificate)
            .setClientCertificatePath(clientCertificatePath)
            ;

        try
        {
            // Call Authlete's /api/backchannel/authentication API.
            return mApi.backchannelAuthentication(request);
        }
        catch (AuthleteApiException e)
        {
            // The API call failed.
            throw apiFailure("/api/backchannel/authentication", e);
        }
    }
private BackchannelAuthenticationResponse callBackchannelAuthentication(
            String parameters, String clientId, String clientSecret,
            String clientCertificate, String[] clientCertificatePath)
    {
        if (parameters == null)
        {
            // Authlete returns different error codes for null and an empty string.
            // 'null' is regarded as a caller's error. An empty string is regarded
            // as a client application's error.
            parameters = "";
        }

        // Create a request for Authlete's /api/backchannel/authentication API.
        BackchannelAuthenticationRequest request = new BackchannelAuthenticationRequest()
            .setParameters(parameters)
            .setClientId(clientId)
            .setClientSecret(clientSecret)
            .setClientCertificate(clientCertificate)
            .setClientCertificatePath(clientCertificatePath)
            ;

        try
        {
            // Call Authlete's /api/backchannel/authentication API.
            return mApi.backchannelAuthentication(request);
        }
        catch (AuthleteApiException e)
        {
            // The API call failed.
            throw apiFailure("/api/backchannel/authentication", e);
        }
    }
Call Authlete's {@code /api/backchannel/authentication} API.