I'm not clear which problem we are discussing:
1/ Ensuring inside jena-permissions that iterators are properly closed.
2/ Ensuring use code using jena-permissions (i.e
SecuredGraph/SecuredModel by name) closes iterators properly.
3/ Ensuring app code that uses the Graph or Model interface (and so may
be Secured* but it does not know) closes iterators properly.
If (3) isn't any change going to impact existing use code?
What's more, it does not seem to work
On 10/03/2021 21:56, Claude Warren wrote:
I think that if the solution was any simpler it would have bit me.
Change ClosableIterator<T> to extend AutoCloseable as well as Iterator.
mark ClosableIterator.close() with an @Override annotation and done.
While Autoclosable throws an exception the ClosableIterator does not so the
try with resources works.
I tried this and then changed
FinderUtils.contains() to be coded as
@Override
public boolean contains(TriplePattern pattern) {
try (ClosableIterator<Triple> it = find(pattern))
{
return it.hasNext();
}
}
and the IDE (Eclipse) does not complain. So I think it will just work.
because writing
public boolean contains(TriplePattern pattern) {
ExtendedIterator<Triple> it = find(pattern);
try {
return it.hasNext();
} finally { it.close(); }
}
is accident-prone?
I changed ClosableIterator as you describe and got hundreds of warnings
from the codebase, and it will happen to user code.
1/
A warning happens on code that is currently correctly written old style as
ExtendedIterator<> iter =
try {
...
} finally { iter.close(); }
Eclipse "quick-fix" does not do a good job on this.
The other "old style" code is where the iterator runs the the end
(exceptions aside).
2/
Sometimes there isn't a warning!
Warning: as expected:
public static void main(String...a) throws FileNotFoundException {
InputStream in = new FileInputStream("");
}
No warning: !!!!
static ExtendedIterator<Triple> foo() { return null; }
public static void main(String...a) {
ExtendedIterator<Triple> iter = foo();
}
Warning:
static ExtendedIterator<Triple> foo() { return null; }
public static void main(String...a) {
ExtendedIterator<Triple> iter = foo();
iter.close();
}
Weird.
That somewhat negates the utility.
Andy
