Call Charging Service

This sample demonstrates a service for specifying the charge rates for calls through the use of 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

Rule 1 : If a local calls was taken during daytime, then the call rate is two dollars per minute.

Rule 2 : If a local call was taken during night, then the call rate is one dollar per minute.

Rule 3 : If an international call was taken during daytime, then the call rate is six dollars per minute.

Rule 4 : If an international was taken during night, then the call rate is four dollars per minute.

Facts

There is one fact named A call has been taken (CallLog). a charge should be calculated for the call (CallCharge) is the result of the rule execution.

package samples.callcharging;
import java.util.Calendar;

/**
 * CallLog fact
 */
public class CallLog {

    private String type;

    private double period;

    public String getType() {
        return type;
    }

    public void setType(String type) {
        this.type = type;
    }

    public double getPeriod() {
        return period;
    }

    public void setPeriod(double period) {
        this.period = period;
    }

    public int now() {
        Calendar cal = Calendar.getInstance();
        return cal.get(Calendar.HOUR_OF_DAY);
    }
}

package samples.callcharging;

/**
 * CallCharge fact
 */
public class CallCharge {

    private double amount;

    public double getAmount() {
        return amount;
    }

    public void setAmount(double amount) {
        this.amount = amount;
    }
}

Rule service configuration (service.rsl)

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

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

                import samples.callcharging.CallLog;
                import samples.callcharging.CallCharge;

                rule "Local Call During Daytime"
                when
                      callLog : CallLog( type == "local")
                           eval((6 < callLog.now()) && (callLog.now()< 18))
                then
                           CallCharge c = new CallCharge();
                           c.setAmount(callLog.getPeriod() * 2);
                           insertLogical(c);
                end

                rule "Local Call During Night"
                when
                      callLog : CallLog( type == "local")
                           eval((18 < callLog.now()) || (callLog.now()< 5))
                then
                           CallCharge c = new CallCharge();
                           c.setAmount(callLog.getPeriod() * 1);
                           insertLogical(c);
                end

                rule "IDD Call During Daytime"
                when
                      callLog : CallLog( type == "idd")
                           eval((6 < callLog.now()) && (callLog.now()< 18))
                then
                           CallCharge c = new CallCharge();
                           c.setAmount(callLog.getPeriod() * 6);
                           insertLogical(c);
                end

                rule "IDD Call During Night"
                when
                      callLog : CallLog( type == "idd")
                           eval((18 < callLog.now()) || (callLog.now()< 5))
                then
                           CallCharge c = new CallCharge();
                           c.setAmount(callLog.getPeriod() * 4);
                           insertLogical(c);
                end

            ]]>
        </rule>
    </ruleSet>
    <operation name="charge">
        <input wrapperElementName="callCharge" namespace="http://com.test/callCharge">
            <fact elementName="callLog" namespace="http://com.test/callCharge" type="samples.callcharging.CallLog"></fact>
        </input>
        <output wrapperElementName="callChargeRespone" namespace="http://com.test/callCharge">
            <fact elementName="callCharge" namespace="http://com.test/callCharge" type="samples.callcharging.CallCharge"></fact>
        </output>
    </operation>
</ruleService>

Executing the service

To execute the service, run the ant command from the <PRODUCT_HOME>/samples/callcharging.service directory to run the CallCharging 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 CallChargingService 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 the following request in the Try-it tool:
```
<type>idd</type> 
<period>12</period>
```
You would get the following response:
```
<amount>48.0</amount>
```
Issue another request as follows:
```
<type>local</type>
<period>12</period>
```
You would get the following result:
```
<amount>12.0</amount>
```

Alternatively, you can use Generate Axis2 Client link 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 data binding classes check box checked.

package test.com.Client;

    import org.apache.axis2.AxisFault;
    import test.com.callcharge.CallCharge;
    import test.com.callcharge.CallChargeE;
    import test.com.callcharge.CallLog;
    import test.com.callcharging.CallChargingServiceStub;

    import java.rmi.RemoteException;

    public class CallChargingTestCase {
        public static void main(String[] args) {
            try {
                CallChargingServiceStub callChargingServiceStub = new CallChargingServiceStub("http://localhost:9763/services/CallChargingService");

                CallChargeE callChargeRequest = new CallChargeE();
                CallLog callLog = new CallLog();
                callLog.setPeriod(200);
                callLog.setType("local");
                CallLog[] callLogs = new CallLog[1];
                callLogs[0] = callLog;

                callChargeRequest.setCallLog(callLogs);

                CallCharge[] callCharges = callChargingServiceStub.charge(callLogs);
                if(callCharges != null){
                    for (CallCharge callCharge : callCharges){
                        System.out.println("Tha charge for the call : " + callCharge.getAmount());

                    }
                }
            } catch (AxisFault axisFault) {
                axisFault.printStackTrace();
            } catch (RemoteException e) {
                e.printStackTrace();
            }

        }
    }