neo4j - 用户定义的过程超时

Question

如何为我的neo4j 用户定义过程实现超时机制？

我的代码就是这样。

@Procedure(value = "nameOfMyProcedure", mode = Mode.WRITE)
@Description("finds the minimal sub-graph from given nodes")
public Stream<Output> nameOfMyProcedure(@Name("p1") Long p1, @Name("p2") Long p2, ...) {
    // there are some codes here. I want to make a timeout mechanism for codes inside here
}

我尝试使用java.util.concurrent.Callable和java.util.concurrent.ExecutorService

AdvancedQuery that = this;
Callable<Output> receiveResponse = () -> {
    // put all the codes inside this callable
    return output;
}

ExecutorService executor = Executors.newSingleThreadExecutor();
Future<Output> future = executor.submit(receiveResponse);
Output result = null;
try {
    result = future.get(10000, TimeUnit.MILLISECONDS);
    log.info("Completed successfully");
} catch (InterruptedException | ExecutionException e) {
    log.info("unexpected error: ", e.getMessage());
} catch (TimeoutException e) {
    log.info("Timed out. Cancelling the runnable...");
    future.cancel(true);
}

executor.shutdown();
if (result == null) {
    return Stream.of(new Output());
}
return Stream.of(result);

我明白了ExecutionException

org.neo4j.kernel.impl.core.ThreadToStatementContextBridge$BridgeNotInTransactionException: 请求的操作无法执行，因为它必须在事务中执行。确保您将操作包装在适当的事务样板中，然后重试。