如何避免Java 8 Files.walk（..）终止原因（java.nio.file.AccessDeniedException）？
如何避免Java 8 Files.walk（..）终止原因（java.nio.file.AccessDeniedException）？
提问于 2018-08-15 06:39:53
/**
* Count files in a directory (including files in all sub
* directories)
*
* @param directory
* the directory to start in
* @return the total number of files
*/
public int countFiles(File dir) {
if (dir.exists())
try (Stream<Path> paths = Files.walk(Paths.get(dir.getPath()), FileVisitOption.FOLLOW_LINKS)) {
return (int) paths.filter(path -> {
// i am using something different here but i changed
// it just for the purpose of StackOverFlow question
return path.toString().contains(".mp3");
}).count();
} catch (IOException ex) {
//Main.logger.log(Level.WARNING, "", ex);
ex.printStackTrace();
}
return 0;
}
StackTrace的错误：
java.io.UncheckedIOException: java.nio.file.AccessDeniedException: C:\$Recycle.B
in\S-1-5-18
at java.nio.file.FileTreeIterator.fetchNextIfNeeded(FileTreeIterator.java:88)
at java.nio.file.FileTreeIterator.hasNext(FileTreeIterator.java:104)
at java.util.Iterator.forEachRemaining(Iterator.java:115)
at java.util.Spliterators$IteratorSpliterator.forEachRemaining(Spliterators.jav
a:1801)
at java.util.stream.AbstractPipeline.copyInto(AbstractPipeline.java:481)
at java.util.stream.AbstractPipeline.wrapAndCopyInto(AbstractPipeline.java:471)
at java.util.stream.ReduceOps$ReduceOp.evaluateSequential(ReduceOps.java:708)
at java.util.stream.AbstractPipeline.evaluate(AbstractPipeline.java:234)
at java.util.stream.LongPipeline.reduce(LongPipeline.java:438)
at java.util.stream.LongPipeline.sum(LongPipeline.java:396)
at java.util.stream.ReferencePipeline.count(ReferencePipeline.java:526)
at smartcontroller.SmartController$InputService$1.countFiles(SmartController.ja
va:2092)
...
Stack Overflow用户
发布于 2018-08-15 16:18:44
可以改进为使用Java 8流和lambdas
int[] count = {0};
try {
Files.walkFileTree(Paths.get(dir.getPath()), new HashSet<FileVisitOption>(Arrays.asList(FileVisitOption.FOLLOW_LINKS)),
Integer.MAX_VALUE, new SimpleFileVisitor<Path>() {
@Override
public FileVisitResult visitFile(Path file , BasicFileAttributes attrs) throws IOException {
System.out.printf("Visiting file %s\n", file);
++count[0];
return FileVisitResult.CONTINUE;
}
@Override
public FileVisitResult visitFileFailed(Path file , IOException e) throws IOException {
System.err.printf("Visiting failed for %s\n", file);
return FileVisitResult.SKIP_SUBTREE;
}
@Override
public FileVisitResult preVisitDirectory(Path dir , BasicFileAttributes attrs) throws IOException {
System.out.printf("About to visit directory %s\n", dir);
return FileVisitResult.CONTINUE;
}
});
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}页面原文内容由Stack Overflow提供。腾讯云小微IT领域专用引擎提供翻译支持
原文链接：
https://stackoverflow.com/questions/-100005994
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