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

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Sample

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configuration

Table of Contents
maxLevel4
minLevel4

Sample

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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.

 

Code Block
languagejava
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 configuration (service.rsl)

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

 

Code Block
languagehtml/xml
<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

Sample

service

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

Info

Before executing this sampleservice, 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

testing the

Service

service

  1. 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.

  2. After deployment, click on List under Services in the main tab of the management console. The service will appear in the Deployed Services page.
  3. Click InsuranceCalculation Service to access the dashboard of the service.
  4. Click Try this service in the Client Operations widget of the dashboard to invoke the Try-it tool.
  5. Issue a request as follows in the Try the InsuranceCalculationService service window.-it tool:

    Code Block
    languagehtml/xml
    <loanType>FHA</loanType>
    <mortgageValue>100000</mortgageValue>
    <downPayment>90000</downPayment>

    You would get the following result.:

    Code Block
    languagehtml/xml
    <annualMIP>1500.0</annualMIP>


  6. Issue another request as follows:

    Code Block
    languagehtml/xml
    <loanType>PMI</loanType>
    <mortgageValue>100000</mortgageValue>
    <downPayment>90000</downPayment>

    You would get the following result:

    Code Block
    languagehtml/xml
    <annualMIP>500.0</annualMIP>
  7. Alternatively, you can click Generate Axis2 Client in the Client Operations widget of the dashboard to invoke the service. A client using generated stub codes is shown below where the codes were generated with the Unpacks the databinding  classes check box checked.

    Code Block
    languagejava
    package org.wso2.carbon.samples;
    
    import org.apache.axis2.AxisFault;
    import org.wso2.carbon.samples.mipCalculateService.clientDetail.Client;
    import org.wso2.carbon.samples.mipCalculateService.clientDetail.MIP;
    import org.wso2.carbon.samples.mipCalculateService.clientDetail.PlaceClientDetail;
    import org.wso2.carbon.samples.mipCalculateService.stub.MIPCalculateServiceStub;
    import java.rmi.RemoteException;
    
    public class MIPCalculateServiceTestCase {
    
        public static void main(String[] args) {
    
            try {
                MIPCalculateServiceStub mipCalculateServiceStub =
                        new MIPCalculateServiceStub("http://localhost:9763/services/MIPCalculateService");
                PlaceClientDetail placeClientDetail = new PlaceClientDetail();
    
                Client client = new Client();
                client.setLoanType("FHA");
                client.setDownPayment(8000);
                client.setMortgageValue(90000);
                Client[] clients = new Client[1];
                clients[0] = client;
    
                MIP[] mips = mipCalculateServiceStub.calculate(clients);
                double result = mips[0].getAnnualMIP();
                System.out.println(result);
    
            } catch (AxisFault axisFault) {
                axisFault.printStackTrace();
            } catch (RemoteException e) {
                e.printStackTrace();
            }
        }
    }
    Excerpt
    hiddentrue

    Mortgage insurance premium calculation service sample of the WSO2 Business Rules Server samples guide.