how to File.listFiles in alphabetical order?
The listFiles
method, with or without a filter does not guarantee any order.
It does, however, return an array, which you can sort with Arrays.sort()
.
File[] files = XMLDirectory.listFiles(filter_xml_files);Arrays.sort(files);for(File _xml_file : files) { ...}
This works because File
is a comparable class, which by default sorts pathnames lexicographically. If you want to sort them differently, you can define your own comparator.
If you prefer using Streams:
A more modern approach is the following. To print the names of all files in a given directory, in alphabetical order, do:
Files.list(Paths.get(dirName)).sorted().forEach(System.out::println)
Replace the System.out::println
with whatever you want to do with the file names. If you want only filenames that end with "xml"
just do:
Files.list(Paths.get(dirName)) .filter(s -> s.toString().endsWith(".xml")) .sorted() .forEach(System.out::println)
Again, replace the printing with whichever processing operation you would like.
I think the previous answer is the best way to do it here is another simple way. just to print the sorted results.
String path="/tmp"; String[] dirListing = null; File dir = new File(path); dirListing = dir.list(); Arrays.sort(dirListing); System.out.println(Arrays.deepToString(dirListing));