Can I use lambda expressions in Jaspersoft Studio 6.2.0? - java-8

Question

I use Jaspersoft Studio 6.2.0, and compile the report in a maven project with dependencies:
<dependency>
<groupId>net.sf.jasperreports</groupId>
<artifactId>jasperreports</artifactId>
<version>6.2.0</version>
</dependency>
<dependency>
<groupId>net.sf.jasperreports</groupId>
<artifactId>jasperreports-fonts</artifactId>
<version>6.0.0</version>
</dependency>
The report is fed with a
JRBeanArrayDataSource beanDS = new JRBeanArrayDataSource(new Incident[]{incident}, false);
I have tried to use a labmda expression in Print When Expression of a band. It seems not to recognise it. The expression is:
$F{actionList} == null || $F{actionList}.stream().allMatch(a -> ActionStatus.COMPLETED.equals(a.getStatus()))
ActionStatus is an Enum. And I get syntax errors like:
net.sf.jasperreports.engine.JRException: Errors were encountered when compiling report expressions class file:
1. a cannot be resolved to a variable
(((java.util.List)field_actionList.getValue()) == null || ((java.util.List)field_actionList.getValue()).stream().allMatch(a -> ActionStatus.COMPLETED.equals(a.getStatus()))) //$JR_EXPR_ID=248$
^
2. Syntax error on token "-", -- expected
(((java.util.List)field_actionList.getValue()) == null || ((java.util.List)field_actionList.getValue()).stream().allMatch(a -> ActionStatus.COMPLETED.equals(a.getStatus()))) //$JR_EXPR_ID=248$
I also tried using the method from the object directly like:
this.hasAllActionsCompleted()
that does the same thing (this is in the Incident object that is set for the report's DS) :
/**
* Checks if the incident has all actions completed
* #return true if all actions are completed or none defined, false otherwise
*/
public boolean hasAllActionsCompleted() {
return actionList == null || actionList.stream().allMatch(a -> ActionStatus.COMPLETED.equals(a.getStatus()));
}
and I get:
net.sf.jasperreports.engine.JRException: Errors were encountered when compiling report expressions class file:
1. The method hasAllActionsCompleted() is undefined for the type Incident_1461053626798_784639
this.hasAllActionsCompleted() //$JR_EXPR_ID=248$
Is there another way to do this? Or should I just set the lambda expression result in a parameter for the report (this is an obvious walkaround, but I was hoping for a direct approach)?

Answer 1

And the answer is change the method to a getter, and use it as a field.
In my case I changed hasAllActionsCompleted to isAllActionsCompleted and added a new field allActionsCompleted as a Boolean. Worked as a charm. Thank you.