# Pass BusinessKey in expression

**URL:** <https://forum.flowable.org/t/pass-businesskey-in-expression/3169>\
**Category:** Flowable Engine\
**Created:** [January 3, 2019, 3:35pm UTC](https://forum.flowable.org/t/pass-businesskey-in-expression/3169 "2019-01-03T15:35:04Z")\
**Posts on this page:** 1\
**Page:** 1

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**Author:** ![garyb](https://avatars.discourse-cdn.com/v4/letter/g/ee59a6/32.png) [@garyb](https://forum.flowable.org/u/garyb)\
**Post date:** [January 3, 2019, 3:35pm UTC](https://forum.flowable.org/t/pass-businesskey-in-expression/3169/1 "2019-01-03T15:35:04Z")

</div>

How do I access the Business Key in an expression?  
I have a method in a Spring service, flowableBpmPlugin;  
public void sendEmail(String reference)  
{  
System.out.println("sendEmail reference= "+reference);  
}

I would like to pass in the business key from a service task. I have tried;

> ${flowableBpmPlugin.sendEmail(execution.businessKey)}

which passes _null_

In order to get this to work I have had to add a new method that accepts the execution.  
public void sendEmail(DelegateExecution e)  
{  
String reference = e.getProcessInstanceBusinessKey();  
System.out.println("sendEmail reference= "+reference);  
}  
and change the expression to

> ${flowableBpmPlugin.sendEmail(execution)}

What do I need to do to pass the process instance business key as a String?