Creating and Deploying the Rule Service

There are two ways to create a rule service using the WSO2 BRS management console, which are:

Rule Service Upload
Rule Service Wizard

Rule Service Upload

This demonstrates how to use the rule service upload UI for deploying a rule service.

Create a valid JAR containing the Java classes of facts and results defined for the Order Approval sample user case in Sample Rule Definition.
Create the Drools file that defines the rules for the sample use case. Note that the file must be in .drl format, not .dsrl.

Create a rule service configuration using the instructions in File-Based Configuration. The configuration file which is named as service.rsl (Rule Service Language) and which is used for the sample is shown below.

service.rsl

<ruleService
        name="OrderApprovalService"
        xmlns="http://wso2.org/carbon/rules"
        targetNamespace="http://com.test/orderApproval">
  <ruleSet>
        <rule resourceType="regular" sourceType="file">orderApprovalRules.drl</rule>
    </ruleSet>
    <operation name="placeOrder">
        <input wrapperElementName="placeOrder" namespace="http://com.test/placeorder">
            <fact elementName="order" namespace="http://com.test/placeorder" type="samples.userguide.PlaceOrder"></fact>
        </input>
        <output wrapperElementName="placeOrderRespone" namespace="http://com.test/placeorder">
            <fact elementName="orderAccept" namespace="http://com.test/placeorder" type="samples.userguide.OrderAccept"></fact>
            <fact elementName="orderReject" namespace="http://com.test/placeorder" type="samples.userguide.OrderReject"></fact>
        </output>
    </operation>
</ruleService>

You have so far created a .jar file, orderApprovalRules.drl and a service.rsl file. Place these files in a hierarchical folder structure as displayed below.
Make an Axis2 archive file (OrderApprovalService.aar in this example) from the above content.
Infor
- To learn how to create an Axis2 service using WSO2 Carbon Studio, refer to: http://markmail.org/download.xqy?id=tsctqe7x5rnwexls&number=1
- To learn how to create an Axis2 service using Eclipse, refer to: http://wso2.org/library/tutorials/create-axis2-web-service-in-3-steps-using-eclipse
Log in to the WSO2 BRS management console and click Upload under Rules Service in the main page.
The Upload Rule Service window opens. Upload the file created in step 4 and click Upload as shown below.
The Deployed Services window opens with the newly uploaded business rules exposed as a service. Click on it to access its dashboard and select the TryIt option on the Client Operations panel in the service dashboard.
The Try-It tool can be used to test the sample through a request similar to the one shown below.
```
<symbol>Company A</symbol>
<quantity>223</quantity>
<price>14</price>
```

Each rule can be tested by changing values in the symbol, price and quantity. For the request given above, the response will be as follows.

<brs:placeOrderResponse>
     <brs:result>
         <brs:OrderAccept xsi:type="ax2277:OrderAccept">
                <ax2275:message>Accepted order for: 223 stocks of Company A at$ 14.0</ax2275:message>
         </brs:OrderAccept>
     </brs:result>
</brs:placeOrderResponse>

The WSDL of the service can also be used to generate client-side code (stub) required for the service invocation. There is an option for code generation in the services management page. A client using generated stub codes is shown below and the codes are generated with option - Unpacks the databinding classes.

package org.wso2.carbon.samples;
import org.wso2.carbon.samples.orderApprovalService.order.OrderAccept;
import org.wso2.carbon.samples.orderApprovalService.order.PlaceOrder;
import org.wso2.carbon.samples.orderApprovalService.order.PlaceOrderE;
import org.wso2.carbon.samples.orderApprovalService.order.PlaceOrderRespone;
import org.wso2.carbon.samples.orderApprovalService.stub.OrderApprovalServiceCallbackHandler;
import org.wso2.carbon.samples.orderApprovalService.stub.OrderApprovalServiceStub;
import java.rmi.RemoteException;

public class PlaceOrderTestCase {

    public static void main(String[] args) {

        try {
            OrderApprovalServiceStub orderApprovalServiceStub = new OrderApprovalServiceStub("http://localhost:9763/services/OrderApprovalService");
            PlaceOrderE placeOrderE = new PlaceOrderE();
            PlaceOrder placeOrder = new PlaceOrder();
            placeOrder.setSymbol("Company A");
            placeOrder.setPrice(150);
            placeOrder.setQuantity(128);
            PlaceOrder[] placeOrders = new PlaceOrder[1];
            placeOrders[0] = placeOrder;
            placeOrderE.setOrder(placeOrders);

            PlaceOrderRespone placeOrderRespone = null; //new PlaceOrderRespone();
            try {
                placeOrderRespone = orderApprovalServiceStub.placeOrder(placeOrders);
            } catch (RemoteException e) {
                e.printStackTrace();  //To change body of catch statement use File | Settings | File Templates.
            }
            OrderAccept[] orderAccepts = placeOrderRespone.getOrderAccept();
            String result = orderAccepts[0].getMessage();
            System.out.println(result);



        } catch (Exception e) {
            e.printStackTrace();
        }
    }
}

Rule Service Wizard

A rules service can be created through the rule service wizard of the WSO2 BRS management console, as follows:

Log in to the WSO2 BRS management console and click Create under Rules Service in the Main page.
The Service Information window opens. Enter the required information and click Next. The service name has to be unique.
The Rule Set Information window appears. There are four ways to specify a rule set or a rule script.
- In-lined : Script is provided in the window itself
- Registry Key: Include the rule script in the system's governance registry. (Multiple scripts can be added here).
- Rule File: Upload a Drools rules file from a folder.
- URL: Upload from a url
Select a value for the Rule Type field to specify the format to be used to capture your business rule logic. The possible values are as follows:
- Regular: If this rule type is selected, a rule set will be used to capture the business rule logic. Since a rule set is more flexible than a decision table, this value should be selected if your rule takes the form of unstructured sentences. You can use this rule type even in situations where your rule takes the form of a table if some of the decision criteria is not applicable and/or output values are not defined.
- Decision Table: If this rule type is selected a decision table will be used to capture your business rule logic. This rule type should be selected if every rule uses the same decision criteria. This enables all the common decision criteria to be captured at once.
Once the rule is uploaded click Next. The Facts Upload window appears to upload facts and results that are used in the rule script. It should be a valid jar file. Multiple jar files can be uploaded. For example, create a jar file from the facts and results defined in Sample Rule Definition.
The Operations Summary window appears, displaying any operations available in the service. You can also use the Add New Operation link to create a new operation.
The Add Operation window appears. Fill in the fields appropriately.
- Name: Operation name which is mandatory.
- Input and output facts: You can use fact "selector" to select a type, which you have already uploaded in the input fact upload step. In this example, one fact is added with the type as samples.userguide.PlaceOrder and two outputs with types as samples.userguide.OrderReject and samples.userguide.OrderAccept. Note that Type is the only mandatory attribute in both input and output facts.
Click the Add button once done. This will bring you to the previous Operations Summary window. Click Finish to create and deploy the rule service.