Re: [aspectj-users] Behaviours of new constructor added by AspectJ ITD

[Alexander Kriegisch <Alexander@xxxxxxxxxxxxxx>]

Hello.

With all due respect: Ramnivas has answered the question before on SO quite patiently. So as not to waste any more of his precious time I recommend you to
 - read his answer,
 - think again, especially about Q1 and
 - learn some basic Java.

Sorry if it sounds rude, but you seem not to appreciate his answer, which is also not very nice.

Regards
Alexander


Am 15.07.2013 um 20:40 schrieb pai <pikapai@xxxxxxxxx>:

> Hi! thanks for the response.
> 
> But it seems you have some misunderstanding about my questions.
> 
> So I made some modifications to make it clear.
> 
> Thank you for the help :)
> 
> 
> 
> I am currently applying AspectJ to our project, and I found a behavior which
> is a bit strange to me.
> 
> *Q1:*
> I added a new constructor to my current class with inter-type declaration,
> and found that the class's member variable is not initialized if the new
> constructor is used to instantiate my class.
> 
> For example:
> 
> The class which I'll add a new constructor to:
> 
>   public class Child {
> 
>       public String name = "John";
> 
>       public Child(String desc) {
>           // TODO Auto-generated constructor stub
>       }
>   } 
> 
> The aspectJ code:
> 
>   public aspect MyTest {
>       public Child.new(String desc, int num) {
>           System.out.println("Child Name:" + this.name);
>       }
>   }
> 
> If I instantiate the Child with the new constructor:
> 
>   new Child("A child", 5)
> 
> the member variable **this.name** is not initialized as will be done with
> the original constructor.
> 
> But, if I call the original constructor:
> 
>   new Child("A child") 
> 
> the member variable **this.name** will be initialized to "John" as usual
> 
> The result:
> 
>> Child Name:null
> 
> **Is this a limitation of AspectJ? Is there anyway to resolve this issue?** 
> 
> I don't really want to add the code for member variable initialization to
> the new constructor.
> 
> *Q2:*
> It seems **in the newly added constructor**, **super.method()** can not be
> correctly resolved.
> 
> 
> The class which I'll add a new constructor to:
> 
>   public class Child extends Parent{
> 
>       public String name = "John";
> 
>       public Child(String desc) {
> 
>       }
>   } 
> 
> **Child** extends **Parent**. **Parent** has a method **init()**
> 
>   public class Parent {
> 
>       public void init() {
>           //....
>       }
> 
>   }
> 
> I add a new constructor for the **Child** in my aspect.
>   public aspect MyTest {
>       public Child.new(String desc, int num) {
>           super.init();
>       }
>   }
> 
> The above aspect code will trigger an exception.
> 
>   Exception in thread "main" java.lang.NoSuchMethodError:
> com.test2.Child.ajc$superDispatch$com_test2_Child$init()V
>       at MyTest.ajc$postInterConstructor$MyTest$com_test2_Child(MyTest.aj:19)
>       at com.test2.Child.<init>(Child.java:1)
>       at MainProgram.main(MainProgram.java:11)
> 
> My workaround is to define **another method** for my class **Child**, and
> indirectly call the super.method() within that method
> 
> 
> For example, add a new method that calls **super.init()** for **Child**
> 
>   public void Child.initState()
>   {
>       super.init();
>   }
> 
> Now, I can call initState() in the newly added constructor like below:
> 
>   public aspect MyTest {
>       public Child.new(String desc, int num) {
>           this.initState();
>       }
>   }
> 
> **Is this a limitation of AspectJ? Is this the only way to resolve this
> issue?** 
> 
> Thank you all for your time :)
> 
> 
> 
> --
> View this message in context: http://aspectj.2085585.n4.nabble.com/Behaviours-of-new-constructor-added-by-AspectJ-ITD-tp4651015p4651019.html
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