Question

Suppose I have the code below that needs to throw an exception from withing an anonymous function without modifying the function:

FOO.doSomething(new Transactable(){
 public void run(FOO foo) {
     // How to proxy a exception throw
     // from here, without modifying the class
 }
});

Like:

@Override
public void run() throws MyCustomException{
       FOO.doSomething(new Transactable(){
           public void run(FOO foo) {
               // How to proxy a exception throw
               // from here, without modifying the class
           }
        });             
}

Answer 1

I have some doubts that I understood this correctly, but here’s my shot. I guess you’re trying to somehow move the exception from the anonymous class and throw it from the parent method:

class ExceptionWrapper {
    public Exception exception;
}

@Override
public void run() throws MyCustomException{
       final ExceptionWrapper ew = new ExceptionWrapper();

       FOO.doSomething(new Transactable(){
           public void run(FOO foo) {
               try {
                   ...
               } catch(MyCustomException ex) {
                   ew.exception = ex;
               }
           }
        });             

        if(ew.exception != null) throw (MyCustomException)ew.exception;
}