Very common need to use for file management issue

CommonFileMethod.java

public class CommonFileManagement(){
//delete folder in android 
    public static void deleteFolderWithContent(String dirName){
        File dir = new File(Environment.getExternalStorageDirectory().toString() + "/"+dirName);
        if (dir.isDirectory())
        {
            String[] children = dir.list();
            for (int i = 0; i < children.length; i++)
            {
                new File(dir, children[i]).delete();
            }
        }
    }

//copy file from one to another
    public static void copy(File src, File dst) throws IOException {
        InputStream in = new FileInputStream(src);
        try {
            OutputStream out = new FileOutputStream(dst);
            try {
                // Transfer bytes from in to out
                byte[] buf = new byte[2048];
                int len;
                while ((len = in.read(buf)) > 0) {
                    out.write(buf, 0, len);
                }
            } finally {
                out.close();
            }
        } finally {
            in.close();
        }
    }
}