android-从/ res / raw文件夹中检索所有文件作为文件类型

Question

How can I retrieve all the files in /res/raw folder as File? I have found this solution, and "New Folder" value I have replaced with "res/raw" as you can see in the following code:

public File[] getRawFiles() {
        File sdCardRoot = Environment.getExternalStorageDirectory();
        File yourDir = new File(sdCardRoot, "res/raw");
        return yourDir.listFiles();
}

When program is started, I get an exception on line return yourDir.listFiles :

Caused by: java.lang.NullPointerException: Attempt to get length of null array

How can I fix this, and what is correct path to "res/raw/" ?

Answer 1

How can I retrieve all the files in /res/raw folder as File?

You cannot do this. As we discussed yesterday , resources are not files on the filesystem of the device. They are files on your development machine. They are merely entries in an APK file on the device.

Either:

• Do whatever you are trying to do some other way that does not involve files, or

• Use openInputStream() on a Resources object (you can get one from any Context via getResources() ), and use Java I/O to copy the contents of a resource to a local file, such as on internal storage , and using reflection to iterate over the actual resources , or

• Switch to using assets/ instead of res/raw/ , as AssetManager allows you to list() assets (though you still only get an InputStream on an asset, as like resources, assets are not files on the device)