android 删除文件以及递归删除文件夹

private void deleteDirectory(File file) {
if (file.isFile()) {
file.delete();
return;
}

if(file.isDirectory()){
File[] childFiles = file.listFiles();
if (childFiles == null || childFiles.length == 0) {
file.delete();
return;
}

for (int i = 0; i < childFiles.length; i++) {
            deleteDirectory(childFiles[i]);
}
file.delete();
}
}