Introduction
This sample demonstrates the stateful behavior of a rule session through a simple banking application which uses business rules. This sample should be deployed in a stateful axis2 session - i.e. session scope or transport scope.
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<ruleService
name="BankingService"
scope="transportsession"
xmlns="http://wso2.org/carbon/rules"
targetNamespace="http://com.test/Banking">
<ruleSet>
<rule resourceType="regular" sourceType="inline">
<![CDATA[
package Banking;
import samples.banking.Account;
import samples.banking.Deposit;
import samples.banking.DepositAccept;
import samples.banking.WithdrawAccept;
import samples.banking.WithdrawReject;
import samples.banking.Withdraw;
rule "Deposit with amount higher than 1000 in an Existing Account" dialect "mvel" no-loop true salience 6
when
$deposit : Deposit( amount > 1000 )
$account : Account( accountNumber == $deposit.accountNumber )
then
$account.increment($deposit.amount * 1.05);
DepositAccept depositAccept = new DepositAccept();
depositAccept.setMessage("Deposit was successfully done. 5 percentage credits is given because the deposit amount is higher than 1000. Amount was : " + $deposit.amount + ". Your account balance is now : "+ $account.balance);
insertLogical(depositAccept);
end
rule "Deposit with amount higher than 1000 in a new Account" dialect "mvel" no-loop true salience 5
when
$deposit : Deposit( amount > 1000)
not( Account( accountNumber == $deposit.accountNumber ) )
then
Account account = new Account();
account.setAccountNumber($deposit.accountNumber);
account.increment($deposit.amount * 1.05);
DepositAccept depositAccept = new DepositAccept();
depositAccept.setMessage("Deposit was successfully done.5 percentage credits is given because the deposit amount is higher than 1000. Amount was : " + $deposit.amount + ". Your account balance is now : "+ account.balance);
retract($deposit);
insert(account);
insertLogical(depositAccept);
end
rule "Deposit in an Existing Account" dialect "mvel" no-loop true salience 4
when
$deposit : Deposit( amount <= 1000 )
$account : Account( accountNumber == $deposit.accountNumber )
then
$account.increment($deposit.amount);
DepositAccept depositAccept = new DepositAccept();
depositAccept.setMessage("Deposit was successfully done. 5 percentage credits would be given if the deposit amount was higher than 1000. Amount was : " + $deposit.amount + ". Your account balance is now : "+ $account.balance);
insertLogical(depositAccept);
end
rule "Deposit in a new Account" dialect "mvel" no-loop true salience 3
when
$deposit : Deposit( amount <= 1000)
not( Account( accountNumber == $deposit.accountNumber) )
then
Account account = new Account();
account.setAccountNumber($deposit.accountNumber);
account.increment($deposit.amount);
DepositAccept depositAccept = new DepositAccept();
depositAccept.setMessage("Deposit was successfully done.5 percentage credits would be given if the deposit amount was higher than 1000. Amount was : " + $deposit.amount + ". Your account balance is now : "+ account.balance);
retract($deposit);
insert(account);
insertLogical(depositAccept);
end
rule "Withdrawing Allow" dialect "mvel" no-loop true salience 2
when
$withdraw : Withdraw()
$account : Account( accountNumber == $withdraw.accountNumber )
eval($account.balance > $withdraw.amount)
then
$account.decrement($withdraw.amount);
WithdrawAccept withdrawAccept = new WithdrawAccept();
withdrawAccept.setMessage("Withdraw was successfully done. Amount was : " + $withdraw.amount + ". Your new account balance is : "+ $account.balance);
insertLogical(withdrawAccept);
end
rule "Withdrawing Deny" dialect "mvel" no-loop true salience 1
when
$withdraw : Withdraw()
$account : Account( accountNumber == $withdraw.accountNumber )
eval($account.balance < $withdraw.amount)
then
WithdrawReject withdrawReject = new WithdrawReject();
withdrawReject.setReason("Withdrawing is only allowed if the account balance is higher than the requested amount. Your account balance is : "+ $account.balance);
insertLogical(withdrawReject);
end
]]>
</rule>
</ruleSet>
<operation name="withDraw">
<input wrapperElementName="withDraw" namespace="http://com.test/withDraw">
<fact elementName="withDraw" namespace="http://com.test/withDraw" type="samples.banking.Withdraw"></fact>
</input>
<output wrapperElementName="withDrawRespone" namespace="http://com.test/withDraw">
<fact elementName="withdrawAccept" namespace="http://com.test/withDraw" type="samples.banking.WithdrawAccept"></fact>
<fact elementName="withdrawReject" namespace="http://com.test/withDraw" type="samples.banking.WithdrawReject"></fact>
</output>
</operation>
<operation name="deposit">
<input wrapperElementName="deposit" namespace="http://com.test/deposit">
<fact elementName="deposit" namespace="http://com.test/deposit" type="samples.banking.Deposit"></fact>
</input>
<output wrapperElementName="depositRespone" namespace="http://com.test/deposit">
<fact elementName="depositAccept" namespace="http://com.test/deposit" type="samples.banking.DepositAccept"></fact>
</output>
</operation>
</ruleService> |
Executing the Sample
To execute the sample, run the ant command from the <BRS_Home>/samples/banking.service directory to run the Banking Service.
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Before executing this sample, 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
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 Exposing Rules as Services.
2. After deployment, the service will appear in the Deployed Services window of the BRS management console. Access the service's dashboard by clicking on it.
3. In the Client Operations widget of the dashboard, invoke the Try-it Tool to test the service.
4. In the service's Try-it window, issue a request similar to the following. As the first step, we do a deposit followed by funds withdrawal.
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