List all the files from all the folder in a single list

Question

Hi I am looking for the solution to list all the files from root/Android device.

Suppose there are 3 folder inside root directory,but I want to display all the files in all of these folder in a single list..

Now If am using

       File f=new File("/sdcard");

Then it will list all the files from the sdcard folder only..and If I will use

       File f=new File("/download");

Then it will list all the files from download folder only ..and if I will use

       File f=new File("/");

Then it will list only root direcoty files...not the files inside /sdcard or /download..

So what steps shall I follow to list all the files with a filter to list only .csv files from all the folder inside root.

Thanks..

Vyacheslav Shylkin · Accepted Answer · 2016-11-17T14:32:48.977

Try this:

 .....
 List<File> files = getListFiles(new File("YOUR ROOT")); 
 ....
 private List<File> getListFiles(File parentDir) {
    ArrayList<File> inFiles = new ArrayList<File>();
    File[] files = parentDir.listFiles();
    for (File file : files) {
        if (file.isDirectory()) {
            inFiles.addAll(getListFiles(file));
        } else {
            if(file.getName().endsWith(".csv")){
                inFiles.add(file);
            }
        }
    }
    return inFiles;
}

or variant without recursion:

private List<File> getListFiles2(File parentDir) {
    List<File> inFiles = new ArrayList<>();
    Queue<File> files = new LinkedList<>();
    files.addAll(Arrays.asList(parentDir.listFiles()));
    while (!files.isEmpty()) {
        File file = files.remove();
        if (file.isDirectory()) {
            files.addAll(Arrays.asList(file.listFiles()));
        } else if (file.getName().endsWith(".csv")) {
            inFiles.add(file);
        }
    }
    return inFiles;
}

Hi Vyacheslav Shilkin, your code worked for me but output is coming after a delay of few seconds(2-3 seconds). Can you suggest something to make it bit quicker? — abhishek kumar gupta, May 24 '13 at 07:31
Great answer, +1 for posting a solution that doesn't use recursion. — the-ginger-geek, Aug 07 '17 at 05:15

score 3 · Answer 2 · answered Oct 08 '13 at 13:27

I've modified Vyacheslav's solution because I needed only file names inside the directory. Maybe it'll be helpfull for someone.

...
List<String> files = getList(new File("YOUR ROOT")); 
...
private List<String> getList(File parentDir, String pathToParentDir) {

    ArrayList<String> inFiles = new ArrayList<String>();
    String[] fileNames = parentDir.list();

    for (String fileName : fileNames) {
        if (fileName.toLowerCase().endsWith(".txt") || fileName.toLowerCase().endsWith(".rtf") || fileName.toLowerCase().endsWith(".txd")) {
            inFiles.add(pathToParentDir + fileName);
        } else {
            File file = new File(parentDir.getPath() + "/" + fileName);
            if (file.isDirectory()) {
                inFiles.addAll(getList(file, pathToParentDir + fileName + "/"));
            }
        }
    }

    return inFiles;
}

Sorry to say, but your modification are no improvements. First of all you add directories with .txt example and I really do not know what pathToParentDir is supposed to be that parentDir.getParent() cannot fix. Lastly, using "/" is discouraged, use File.separator instead. — Michel, Apr 19 '14 at 06:17

score 1 · Answer 3 · answered Mar 02 '12 at 09:39

1

You can use following method,

private int readLogList( String filePath )
{
    File directory = Environment.getExternalStorageDirectory();

    File folder = new File( directory + ConstantCodes.FILE_SEPARATOR + filePath );

    if ( !folder.exists() )
    {
        return 0;
    }

    return  folder.list().length;
}

answered Mar 02 '12 at 09:39

Lucifer

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1

But here still I need to pass filePath? Can't I access all the files from all the directories – Kanika Mar 02 '12 at 09:44
then you need to call this method recursively – Lucifer Mar 02 '12 at 09:46

List all the files from all the folder in a single list

3 Answers3

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