Android get all files in directory nullpointerexception

Question

I'm trying to get all files of a specific directory on the SD card. Therefore I found this function

public static 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(".mp3")){
                inFiles.add(file);
            }
        }
    }

    return inFiles;
}

The problem is the following: If the folder is empty, it will throw a NullPointerException. How can I avoid this?

Permissions for read and write on external storage are set.

you have to also check for number of files in every folder. If less than or equal to 0 dont add files. This will resolve the issue. Just check whether folder has files or not — Vilas, Feb 01 '15 at 09:55
possible duplicate of [What is a Null Pointer Exception, and how do I fix it?](http://stackoverflow.com/questions/218384/what-is-a-null-pointer-exception-and-how-do-i-fix-it) — Simon, Feb 01 '15 at 10:48

score 2 · Accepted Answer · answered Feb 01 '15 at 09:55

2

there is not much to do, if you have to check against null

File[] files = parentDir.listFiles();
if (files == null) {
  return inFiles;
}

in your case inFiles is an empty collection, try to iterating on an empty collection will not case any issues

answered Feb 01 '15 at 09:55

Blackbelt

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Android get all files in directory nullpointerexception

1 Answers1