Kafka KsqlDB UDF (scalar function)

LoanUdf.java

import io.confluent.ksql.function.udf.Udf;
import io.confluent.ksql.function.udf.UdfDescription;
import io.confluent.ksql.function.udf.UdfParameter;

@UdfDescription(name = "loan_installment", category = "LOAN", author = "Timotius Pamungkas", version = "1.0.0", description = "User defined function for sample scalar loan business logic.")
public class LoanUdf {

	@Udf(description = "Estimate monthly loan installment for loan principal amount X, "
			+ "with loan interest rate per year is Y %, " + "over loan period Z month(s), "
			+ "roundest to 2 digit decimal. All parameters are mandatory and can only accept value greater than 1")
	public double estimateMonthlyLoanInstallment(
			@UdfParameter(description = "Loan principal amount") double principalLoanAmount,
			@UdfParameter(description = "Annual interest rate (in percent)") double annualInterestRate,
			@UdfParameter(description = "Loan period in month") int loanPeriodMonth) {
		return LoanCalculator.calculateMonthlyInstallment(principalLoanAmount, annualInterestRate, loanPeriodMonth);
	}

	@Udf(description = "Estimate monthly loan installment for loan principal amount X, "
			+ "with loan interest rate per year is Y %, " + "over loan period Z month(s), "
			+ "roundest to 2 digit decimal. All parameters are mandatory and can only accept value greater than 1. "
			+ "This assume the loan period is 12 months.")
	public double estimateMonthlyLoanInstallment(
			@UdfParameter(description = "Loan principal amount") double principalLoanAmount,
			@UdfParameter(description = "Annual interest rate (in percent)") double annualInterestRate) {
		return LoanCalculator.calculateMonthlyInstallment(principalLoanAmount, annualInterestRate, 12);
	}

}