public static void createPaymentSession() {
    AlipayPaymentSessionRequest alipayPaymentSessionRequest = new AlipayPaymentSessionRequest();
    alipayPaymentSessionRequest.setProductCode(ProductCodeType.AGREEMENT_PAYMENT);
    alipayPaymentSessionRequest.setProductScene(ProductSceneConstants.EASY_PAY);

    // replace with your paymentRequestId
    String paymentRequestId = UUID.randomUUID().toString();
    alipayPaymentSessionRequest.setPaymentRequestId(paymentRequestId);

    // set amount
    // you should convert amount unit(in practice, amount should be calculated on your serverside)
    Amount amount = Amount.builder().currency("HKD").value("98080").build();
    alipayPaymentSessionRequest.setPaymentAmount(amount);

    //set settlement currency
    SettlementStrategy settlementStrategy = new SettlementStrategy();
    settlementStrategy.setSettlementCurrency("USD");
    alipayPaymentSessionRequest.setSettlementStrategy(settlementStrategy);

    // set paymentMethod
    PaymentMethod paymentMethod = PaymentMethod.builder().paymentMethodType("ALIPAY_HK").build();
    alipayPaymentSessionRequest.setPaymentMethod(paymentMethod);

    // set agreementInfo
    // replace with your authState
    String authState = UUID.randomUUID().toString();
    // The login ID that the user used to register in the payment method client. The login ID can be the user's email address or phone number.
    // Specify this parameter to free users from manually entering their login IDs.
    String userLoginId = "852-91234567";
    AgreementInfo agreementInfo = AgreementInfo.builder().authState(authState).userLoginId(userLoginId).build();
    alipayPaymentSessionRequest.setAgreementInfo(agreementInfo);

    // set buyer info
    Buyer buyer = Buyer.builder().referenceBuyerId("yourBuyerId").build();

    // replace with your orderId
    String orderId = UUID.randomUUID().toString();
    // set order Info
    Order order = Order.builder().referenceOrderId(orderId).
            orderDescription("antom api testing order").orderAmount(amount).buyer(buyer).build();
    alipayPaymentSessionRequest.setOrder(order);

    // replace with your notify url
    alipayPaymentSessionRequest.setPaymentNotifyUrl("http://www.yourNotifyUrl.com");

    // replace with your redirect url
    alipayPaymentSessionRequest.setPaymentRedirectUrl("http://www.yourRedirectUrl.com");

    AlipayPaymentSessionResponse alipayPaymentSessionResponse;
    try {
        alipayPaymentSessionResponse = CLIENT.execute(alipayPaymentSessionRequest);
    } catch (AlipayApiException e) {
        String errorMsg = e.getMessage();
        // handle error condition
    }
}