如何关闭 Java 中的隐式流？

Question

Files.walk 是我应该关闭的流之一，但是，如何在如下代码中关闭流？下面的代码是否有效，或者我是否需要重写它以便我可以访问流以关闭它？

List<Path> filesList = Files.walk(Paths.get(path)).filter(Files::isRegularFile ).collect(Collectors.toList());

Answer 1

根据 Files.walk method documentation:

The returned stream encapsulates one or more DirectoryStreams. If timely disposal of file system resources is required, the try-with-resources construct should be used to ensure that the stream's close method is invoked after the stream operations are completed. Operating on a closed stream will result in an IllegalStateException.

强调我的。

Answer 2

您应该将它与 try-with-resource 一起使用，如下所示：

try(Stream<Path> path = Files.walk(Paths.get(""))) {
    List<Path> fileList = path.filter(Files::isRegularFile)
                               .collect(Collectors.toList());
}

Files.walk 的 apiNote 明确显示为：

This method must be used within a try-with-resources statement or similar
control structure to ensure that the stream's open directories are closed
promptly after the stream's operations have completed.

如何关闭 Java 中的隐式流？

How to close implicit Stream in Java?

java

java-8

try-with-resources

java-stream