LambdaLogicTest

This is a java IRecipientBookingsCurrencyAmountsEvaluator interface implementation with InvoiceRecipientBookingsCurrencyAmountsEvaluator for lambda logic short project test.

Usage

InvoiceRecipientBookingsCurrencyAmountsEvaluator evaluator = new InvoiceRecipientBookingsCurrencyAmountsEvaluator(); 
List<Booking> bookings = new ArrayList<Booking>() {
			/**
			 * 
			 */
			private static final long serialVersionUID = 1L;};
bookings.add(new Booking(1L, new Price(TypeHelper.toBigDecimal("0.10"), "usd", TypeHelper.toBigDecimal("19"), false), 
null, null, null, TypeHelper.toBigDecimal("0.09"), null, null, null, 1L, null));
evaluator.calculate(bookings, recipientPK);

Implementation Details

InvoiceRecipientBookingsCurrencyAmountsEvaluator implements four methods of the parent interface.

calculate
getTotalAmount
getPaidAmount
getOpenAmount The latter three methods are used to retrieve resultes calculated with the calculate method.

Problem

The calculate method should add up the total amount, the paid amount and open amount of a list of Bookings for the given invoice recipient ID satisfying the requirements and conditions provided below:

Implementation does not mix-up gross and net amounts
minimize rounding errors
ignore bookings that doesn't belong to the given invoice recipient PK
ignore bookings with both paid amount and total amount of 0
throw exception if any two relevant bookings have different currencies.

Solution

The implementation assumes that:

totalAmount is the total gross amount of list of bookings.
totalPaidAmount is the total paid amount of list of bookings.
totalOpenAmount is the total open(unpaid) amount of list of bookings.

Given (from the classes) that main price, add price 1, add price 2 and paid amounts are rounded to two decimal points, multiplying them by 100 would make the decimal points .00. This multiplication helps us avoid adding up rounding errors because multiplying two BigDecimal objects with the first one .00 decimal points and .ab(two significant figures) decimal points will result in a BigDecimal of two significant figures. Therefore the original value of calcultions in gross, net, and tax amount would be preserved.

Testing

A test package is provided along with one test class CalculateBookingTest. The test package has a TestRunner, which up on execution runs the CalculateBookingTest.

Run test: compile TestRunner.java using javac
java TestRunner

Refer to a Test Documentation

License

MIT