I have an apex class as below with a wrapper:

public class lightningController{ public class ContactWrappertest{ @AuraEnabled public boolean checked {get; set;} @AuraEnabled public Contact cont {get; set;}

    public ContactWrappertest(Boolean isChecked, Contact c){
        this.checked = isChecked;
        this.cont = c;
    }
}

Now when i try to create a lightning component attribute as below and save it:

I get below error on Save: Failed to save lightningComponent.cmp: Invalid aura:attribute type: ContactWrappertest[]: Source

Can someone help me understand the issue here and try to resolve it?