For details on hash calculation for TPV, refer here
For UPI
To Pay using UPI, you need to pass beneficiaryAccountNumber param as below
// For single account number
mPaymentParams.setBeneficiaryAccountNumber("123456789");
mPaymentParams.setIfscCode("SBIN000700");
// For multiple account numbers
mPaymentParams.setBeneficiaryAccountNumber("123456789|23456782|1234567");
mPaymentParams.setIfscCode("SBIN000700|KTKN2937492|ICIC0002522");
// For single account number
mPaymentParams.beneficiaryAccountNumber = "123456789"
mPaymentParams.ifscCode = "SBIN000700"
// For multiple account numbers
mPaymentParams.beneficiaryAccountNumber = "123456789|23456782|1234567"
mPaymentParams.ifscCode = "SBIN000700|KTKN2937492|ICIC0002522"
For UPI Collect
After setting the above parameters for UPI Collect transaction, you can get the payment post params using below
// To provide customer VPA
mPaymentParams.setVpa("valid VPA");
try {
mPostData = new PaymentPostParams(mPaymentParams, PayuConstants.UPI).getPaymentPostParams();
} catch (Exception e) {
e.printStackTrace();
}