Insurance Calculation Service

This sample demonstrates a service for calculating Mortgage Insurance Premium (MIP) using business rules.

Prerequisites

To run this sample:

Windows, Linux or Solaris operating system should exist.
WSO2 BRS should be installed. To install the BRS, refer Installing the Product. This also includes installing Apache Ant as one of the Installation Prerequisites.
WSO2 BRS should be started as described in Running the Product.

Sample configuration

Sample rule definition

Rules
The mortgage insurance rate is 0.5 for MIP insurance and 1.5 for FHA loans.

Facts

There is one fact named Client. The result of the rule execution is Mortgage Insurance Premium.

package samples.MIPCalculate;

/**
 * Client fact
 */
public class Client {

    private String loanType;

    private double mortgageValue;

    private double downPayment;

    public String getLoanType() {
        return loanType;
    }

    public void setLoanType(String loanType) {
        this.loanType = loanType;
    }

    public double getMortgageValue() {
        return mortgageValue;
    }

    public void setMortgageValue(double mortgageValue) {
        this.mortgageValue = mortgageValue;
    }

    public double getDownPayment() {
        return downPayment;
    }

    public void setDownPayment(double downPayment) {
        this.downPayment = downPayment;
    }
}

package samples.MIPCalculate;

/**
 * MIP - Mortgage Insurance Premium
 */
public class MIP {

    private double annualMIP;

    public double getAnnualMIP() {
        return annualMIP;
    }

    public void setAnnualMIP(double annualMIP) {
        this.annualMIP = annualMIP;
    }
}

Rule service configuration (service.rsl)

An in-line rule set is used within the service.rsl file as follows.

<ruleService
        name="MIPCalculateService"
        xmlns="http://wso2.org/carbon/rules"
        targetNamespace="http://com.test/MIPCalculateService">
    <ruleSet>
        <rule resourceType="regular" sourceType="inline">
            <![CDATA[
                package MIPCalculateService

                import samples.MIPCalculate.Client;
                import samples.MIPCalculate.MIP;

                rule "Calculate the MIP for PMI " no-loop true
                when
                    user : Client(loanType == "PMI")
                then
                    MIP mip = new MIP();
                    double loanAmount = user.getMortgageValue() - user.getDownPayment();
                    double lvt = loanAmount / user.getMortgageValue();
                    double lvtAmount = lvt * user.getMortgageValue();
                    mip.setAnnualMIP(lvtAmount * 0.05);
                    insertLogical(mip);

                end

                rule "Calculate the MIP for FHA loan" no-loop true
                when
                    user : Client(loanType == "FHA")
                then
                    MIP mip = new MIP();
                    double loanAmount = user.getMortgageValue() - user.getDownPayment();
                    double lvt = loanAmount / user.getMortgageValue();
                    double lvtAmount = lvt * user.getMortgageValue();
                    mip.setAnnualMIP(lvtAmount * 0.15);
                    insertLogical(mip);
                end
            ]]>
        </rule>
    </ruleSet>
    <operation name="calculate">
        <input wrapperElementName="placeClientDetail" namespace="http://com.test/placeClientDetail">
            <fact elementName="clientDetail" namespace="http://com.test/placeClientDetail" type="samples.MIPCalculate.Client"></fact>
        </input>
        <output wrapperElementName="placeClientDetailRespone" namespace="http://com.test/placeClientDetail">
            <fact elementName="MIP" namespace="http://com.test/placeClientDetail" type="samples.MIPCalculate.MIP"></fact>
        </output>
    </operation>
</ruleService>

Executing the service

To execute the service, run the ant command from the <PRODUCT_HOME>/samples/MIPCalculate.service directory to run the InsuranceCalculation Service.

Before executing this service, it is recommended that you refer Exposing Rules as Services which explains in detail the process of writing and deploying a business rule.

Deploying and testing the service

Deploy the rule service through the BRS management console. You can follow either of the two methods:
- Bundle all artifacts in an .aar file and upload it (Rule Service -> Upload menu).
- Create using the Rule Service wizard UI (Rule Service -> Create menu).
The above steps are discussed in detail in section Exposing Rules as Services.
After deployment, click on List under Services in the main tab of the management console. The service will appear in the Deployed Services page.
Click InsuranceCalculation Service to access the dashboard of the service.
Click Try this service in the Client Operations widget of the dashboard to invoke the Try-it tool.

Issue a request as follows in the Try-it tool:

<loanType>FHA</loanType>
<mortgageValue>100000</mortgageValue>
<downPayment>90000</downPayment>

You would get the following result:

<annualMIP>1500.0</annualMIP>

Issue another request as follows:

<loanType>PMI</loanType>
<mortgageValue>100000</mortgageValue>
<downPayment>90000</downPayment>