broken and correct
While looking for references on the web I cam across these two methids
publicstaticvoid broken()throws FileNotFoundException
{
System.out.println("Executing method broken");
FileReader obj = recreateIt();
WeakReference wr =new WeakReference(obj);
System.out.println("wr refers to object " + wr.get());
System.out.println("Now, clear the reference and run GC");
//Clear the strong reference, then run GC to collect obj.
obj =null;
System.gc();
System.out.println("wr refers to object " + wr.get());
//Now see if obj was collected and recreate it if it was.
obj = (FileReader)wr.get();
if (obj ==null)
{
System.out.println("Now, recreate the object and wrap it
in a WeakReference");
wr =new WeakReference(recreateIt());
System.gc();//FileReader object is NOT pinned...there is no
//strong reference to it. Therefore, the next
//line can return null.
obj = (FileReader)wr.get();
}
System.out.println("wr refers to object " + wr.get());
}
publicstaticvoid correct()throws FileNotFoundException
{
System.out.println("");
System.out.println("Executing method correct");
FileReader obj = recreateIt();
WeakReference wr =new WeakReference(obj);
System.out.println("wr refers to object " + wr.get());
System.out.println("Now, clear the reference and run GC");
//Clear the strong reference, then run GC to collect obj
obj =null;
System.gc();
System.out.println("wr refers to object " + wr.get());
//Now see if obj was collected and recreate it if it was.
obj = (FileReader)wr.get();
if (obj ==null)
{
System.out.println("Now, recreate the object and wrap it
in a WeakReference");
obj = recreateIt();
System.gc();//FileReader is pinned, this will not affect
//anything.
wr =new WeakReference(obj);
}
System.out.println("wr refers to object " + wr.get());
}
I have not been able to figure out why one is broken while the other is correct, they both seem identical to me
