Cursor.count( ) leaves open cursors?

Question

Hi, I am seeing a weird scenario inside a JUnit test -- they symptom is if I call cursor.count( ); in the code, and then close everything properly (I think), when I call close( ) on the environment, it throws a DB exception and claims there are cursors still open. If I comment out the call to cursor.count( ); this exception goes away.
Example inside JUnit test:
EntityIndex<Long, FaceEdge> subIndex = da.faceEdgeByEdgeId.subIndex(12L);
assertFalse(cursor.count( ) == 0);
try {
   for (FaceEdge fe : cursor) {
       assertTrue(fe.getEdgeId( ) == 12L);
   } finally {
       cursor.close( );
}The JUnit tearDown looks like this:
super.tearDown( );
myDbEnv.close( );...and myDbEnv.close( ) looks like this:
if (store != null) {
   try {
       store.close( );
   } catch(DatabaseException dbe) {
      etc.
if(myEnv != null) {
   try {
       myEnv.close( );
   } catch(DatabaseException dbe) {
      // this gets caught and says there are cursors still open
}The comment above is where the exception is caught. I use no other cursors anywhere, and if I comment out the line:
assertFalse(cursors.count( ) == 0);..in the JUnit test, the exception goes away.

Answer 1

Hello,
EntityCursor<FaceEdge> cursor = subIndex.entities();
assertFalse(cursor.count( ) == 0);I think the problem is that you're calling EntityCursor.count for an uninitalized cursor. The cursor must be advanced to the first entity before calling count() is allowed. In this situation a DatabaseException will be thrown with an "uninitialized cursor" message.
Probably what is happening in your JUnit test is that the exception is thrown but your tearDown method still executes, or perhaps you have a finally block, and you're trying to close the EntityStore or the Environment. If you try to close the store or the environment with cursors left open, you'll get an exception telling you to close the cursors. Because of this second exception, you don't see the first exception about the cursor being uninitialized.
I see this problem a lot in my own JUnit tests. :-) What I do is, in the tearDown method I put the calls to close the store and the environnment in a try/catch block. If an exception occurs, I print it, but I don't rethrow it. This allows the original exception (the one thrown by EntityCursor.count in your case) to be reported by JUnit. For example:
public void tearDown() {
    if (store != null) {
        try {
            store.close();
        } catch (Throwable e) {
            System.out.println("During tearDown: " + e);
        store = null;
    if (env != null) {
        try {
            env.close();
        } catch (Throwable e) {
            System.out.println("During tearDown: " + e);
        env = null;
}Mark