極其緩慢的文件使用Java + SAMBA + Win 7的

Question

我已經確定了調用Java的File.listFiles()在從Win 7的客戶端文件夾SAMBA是極其緩慢，比從Mac客戶端較慢實際上幾乎100倍上市。 （這兩個客戶端都運行Java 7）。兩個客戶端自然在同一個1GB局域網上。客戶已經從他的Win XP客戶端進行測試，並且獲得了比他的Win7客戶端更好的性能。有誰知道如何解決這個問題？

一些測試數據，其中包括定時： 清單超過SAMBA 31頁的文件夾（ 「QNAP」 NAS磁盤）：在Mac

 
listing \\nas\Public\David\Remote Stocks: 0.0s 
listing \\nas\Public\David\Remote Stocks\Animals: 0.093s 
listing \\nas\Public\David\Remote Stocks\Animals\.jalbum: 0.312s 
listing \\nas\Public\David\Remote Stocks\Animals\.jalbum\thumbs: 0.405s 
listing \\nas\Public\David\Remote Stocks\album: 1.248s 
listing \\nas\Public\David\Remote Stocks\album\Animals: 1.31s 
listing \\nas\Public\David\Remote Stocks\album\Animals\thumbs: 1.388s 
listing \\nas\Public\David\Remote Stocks\album\Animals\slides: 1.762s 
listing \\nas\Public\David\Remote Stocks\album\Animals\res: 2.542s 
listing \\nas\Public\David\Remote Stocks\album\Sports: 2.761s 
listing \\nas\Public\David\Remote Stocks\album\Sports\thumbs: 2.839s 
listing \\nas\Public\David\Remote Stocks\album\Sports\slides: 3.229s 
listing \\nas\Public\David\Remote Stocks\album\Sports\res: 3.978s 
listing \\nas\Public\David\Remote Stocks\album\res: 4.196s 
listing \\nas\Public\David\Remote Stocks\album\Scenic: 4.695s 
listing \\nas\Public\David\Remote Stocks\album\Scenic\thumbs: 4.773s 
listing \\nas\Public\David\Remote Stocks\album\Scenic\slides: 5.194s 
listing \\nas\Public\David\Remote Stocks\album\Scenic\res: 5.99s 
listing \\nas\Public\David\Remote Stocks\album\People: 6.208s 
listing \\nas\Public\David\Remote Stocks\album\People\thumbs: 6.302s 
listing \\nas\Public\David\Remote Stocks\album\People\slides: 6.692s 
listing \\nas\Public\David\Remote Stocks\album\People\res: 7.472s 
listing \\nas\Public\David\Remote Stocks\.jalbum: 7.659s 
listing \\nas\Public\David\Remote Stocks\Sports: 7.768s 
listing \\nas\Public\David\Remote Stocks\Sports\.jalbum: 7.909s 
listing \\nas\Public\David\Remote Stocks\Sports\.jalbum\thumbs: 7.987s 
listing \\nas\Public\David\Remote Stocks\Scenic: 8.486s 
listing \\nas\Public\David\Remote Stocks\Scenic\.jalbum: 8.642s 
listing \\nas\Public\David\Remote Stocks\Scenic\.jalbum\thumbs: 8.72s 
listing \\nas\Public\David\Remote Stocks\People: 9.282s 
listing \\nas\Public\David\Remote Stocks\People\.jalbum: 9.422s 

同一列表：

運7

 
listing /Volumes/Public/David/Remote Stocks: 0.0s 
listing /Volumes/Public/David/Remote Stocks/Animals: 0.013s 
listing /Volumes/Public/David/Remote Stocks/Animals/.jalbum: 0.018s 
listing /Volumes/Public/David/Remote Stocks/Animals/.jalbum/thumbs: 0.022s 
listing /Volumes/Public/David/Remote Stocks/album: 0.027s 
listing /Volumes/Public/David/Remote Stocks/album/Animals: 0.03s 
listing /Volumes/Public/David/Remote Stocks/album/Animals/thumbs: 0.032s 
listing /Volumes/Public/David/Remote Stocks/album/Animals/slides: 0.034s 
listing /Volumes/Public/David/Remote Stocks/album/Animals/res: 0.038s 
listing /Volumes/Public/David/Remote Stocks/album/Sports: 0.04s 
listing /Volumes/Public/David/Remote Stocks/album/Sports/thumbs: 0.042s 
listing /Volumes/Public/David/Remote Stocks/album/Sports/slides: 0.046s 
listing /Volumes/Public/David/Remote Stocks/album/Sports/res: 0.05s 
listing /Volumes/Public/David/Remote Stocks/album/res: 0.052s 
listing /Volumes/Public/David/Remote Stocks/album/Scenic: 0.058s 
listing /Volumes/Public/David/Remote Stocks/album/Scenic/thumbs: 0.064s 
listing /Volumes/Public/David/Remote Stocks/album/Scenic/slides: 0.068s 
listing /Volumes/Public/David/Remote Stocks/album/Scenic/res: 0.074s 
listing /Volumes/Public/David/Remote Stocks/album/People: 0.08s 
listing /Volumes/Public/David/Remote Stocks/album/People/thumbs: 0.082s 
listing /Volumes/Public/David/Remote Stocks/album/People/slides: 0.085s 
listing /Volumes/Public/David/Remote Stocks/album/People/res: 0.089s 
listing /Volumes/Public/David/Remote Stocks/.jalbum: 0.091s 
listing /Volumes/Public/David/Remote Stocks/Sports: 0.103s 
listing /Volumes/Public/David/Remote Stocks/Sports/.jalbum: 0.106s 
listing /Volumes/Public/David/Remote Stocks/Sports/.jalbum/thumbs: 0.108s 
listing /Volumes/Public/David/Remote Stocks/Scenic: 0.11s 
listing /Volumes/Public/David/Remote Stocks/Scenic/.jalbum: 0.122s 
listing /Volumes/Public/David/Remote Stocks/Scenic/.jalbum/thumbs: 0.124s 
listing /Volumes/Public/David/Remote Stocks/People: 0.126s 
listing /Volumes/Public/David/Remote Stocks/People/.jalbum: 0.133s 

我終於嘗試在Windows上執行多線程列表來克服網絡延遲效應。它有所幫助 - 從9到3秒，即3倍的速度，但仍然顯着低於我的MacBook Pro客戶端測量的0.133s的性能。

Answer 1

問題通過使用Files.walkFileTree API解決。有了它，我可以通過一個SAMBA網絡IO調用來獲取文件夾中所有文件的所有屬性。

Answer 2

我想你偶然發現了一個已知的Windows問題。

也許這篇文章可以幫助你：http://www.sysprobs.com/windows-7-network-slow

編輯：

如果您確信，當它連接到由較早的SMB協議公開分享你的問題是不是由於操作系統的不良行爲，那麼它就是一個（沒有聽說過的）慢於JDK實現的緩慢。

的OpenJDK的和Oracle Java的java.io.File.listFiles()代表，後者又是平臺特定的方式通過java.io.UnixFileSystem，java.io.Win32FileSystem，和java.io.WinNTFileSystem實現的（未曝光）的抽象類java.io.FileSystem的String [] list()方法。

他們的list()函數總是native，所以我認爲緩慢是歸因於JRE附帶的DLL實現。

我們在Windows XP中有關文件瀏覽的類似問題。這是JRE很多時候的一個傑出的bug。