【Java记录】try-with-resources的一个坑-优快云博客

##【Java记录】try-with-resources的一个坑

今天处理 AsynchronousFileChannel 时候的一个问题，代码如下：

public static void main(String[] args) throws Exception {

    String filePath = "/home/xe/git/osc/JavaNote/Lang/data/Test.java";
    ExecutorService executorService = Executors.newSingleThreadExecutor();
    Set<OpenOption> openOptions = new HashSet<>(Arrays.asList(new StandardOpenOption[]{StandardOpenOption.READ}));

    try (AsynchronousFileChannel asynchronousFileChannel = AsynchronousFileChannel.open(Paths.get(filePath), openOptions, executorService)) {
        ByteBuffer buffer = ByteBuffer.allocate(1024);
        asynchronousFileChannel.read(buffer, 0, buffer, new CompletionHandler<Integer, ByteBuffer>() {
            @Override
            public void completed(Integer result, ByteBuffer attachment) {
                System.out.println("completed,result = " + result);
                executorService.shutdown();
            }

            @Override
            public void failed(Throwable exc, ByteBuffer attachment) {
                System.out.println("failed");
                exc.printStackTrace();
                executorService.shutdown();
            }
        });
    } catch (Exception e) {
    }
}

一直提示：

java.nio.channels.AsynchronousCloseException

一直找不到问题的原因，因为我并没有显式的去关闭 AsynchronousFileChannel，后来才发现，是被 try-with-resources 特性给关闭了，悲伤的故事。

所以，在异步调用中，还是谨慎的处理通告的关闭操作比较好。

转载于:https://my.oschina.net/xesam/blog/413018