/premium-calculator

Primary LanguageJava

Premium Calculator

Premium Calculator is a homework project where requirement is to create a calculator that calculates premium for given policy.

Prerequisites

  • Java 14

Usage

Use PremiumCalculatorFactory to retrieve PremiumCalculator for provided Currency.

Currency is needed to set scale for BigDecimal used for currency operations.

    Currency currency = Currency.getInstance("EUR");
    PremiumCalculator premiumCalculator = PremiumCalculatorFactory.getPremiumCalculator(currency);

To calculate premium provide or build Policy object and use PremiumCalculator#calculate(Policy policy).

    Policy policy = Policy.builder()
            .withPolicyNumber("LV20-02-100000-5")
            .withStatus(PolicyStatus.APPROVED)
            .withPolicyObject(PolicyObject.builder()
                    .withObjectName("A House")
                    .withPolicySubObject(PolicySubObject.builder()
                            .withName("TV")
                            .withRiskType(RiskType.FIRE)
                            .withSumInsured(500.00)
                            .build())
                    .withPolicySubObject(PolicySubObject.builder()
                            .withName("TV")
                            .withRiskType(RiskType.THEFT)
                            .withSumInsured(102.51)
                            .build())
                    .build())
            .build();
    BigDecimal premium = premiumCalculator.calculate(policy);

Implementation

Overall calculation logic is following:

  1. Grouping all policy sub-objects by risk type
  2. Summing the sum insured for grouped sub-objects
  3. Applying coefficient based on risk type
  4. Summing premiums from every risk type

In order to apply this logic calculation is split into two types: policy-based and risk-based calculation.

Policy-based calculation is handled by PremiumCalculatior which groups policy sub-objects by risk type, aggregates their sum insured, and applying risk-based logic on it.

Risk-based calculation is handled by RiskCalculator that applies a different coefficient based on a given sum insured.

Adding new RiskCalculator

In order to add new RiskCalculaor following steps should be done:

  1. Create new risk calculator class by implementing RiskCalculator interface
  2. Add new risk type into RiskType enum
  3. Add newly created risk calculator to RiskCalculatorFactory

Adding new risk type into RiskType enum without adding risk calculator to the factory with trigger compile error. This will ensure that RiskCalculator will be added as well.