CancellableStatement

gistfile1.java

public class CancellableStatement {
	private static final Tuple nullTuple = new Tuple(null, null);
	private final ExecutorService priorityExecutorService;
	
	private final AtomicReference<Tuple> reference = new AtomicReference<>(nullTuple);
	private final Promise<String> cancellationWatcher;

	private static class Tuple {
		private final OracleConnection oracleConnection;
		private final CallableStatement callableStatement;
		public Tuple(OracleConnection oracleConnection, CallableStatement callableStatement) {
			this.oracleConnection = oracleConnection;
			this.callableStatement = callableStatement;
		}
	}

	public CancellableStatement(ExecutorService priorityExecutorService, Promise<String> cancellationWatcher) {
		this.priorityExecutorService = priorityExecutorService;
		this.cancellationWatcher = cancellationWatcher;
	}

	/*
	 * Cancel/abort the statement/connection
	 */
	public void cancel() {
		Tuple tuple = reference.getAndSet(null);
		try {
			if(tuple != null && tuple.callableStatement != null) {
				tuple.callableStatement.cancel();
				tuple.callableStatement.close();
			}
		} catch(Throwable t) {
			listener.cancellationFailure(t);
		}

		try {
			if(tuple != null && tuple.oracleConnection != null) {
				tuple.oracleConnection.abort(priorityExecutorService);
			}
		} catch(Throwable t) {
			listener.cancellationFailure(t);
		}
	}
}