求助，读取txt

[python_0]

各位老大抽空帮忙看看，死活读不出来，文件在sd卡的download里，txt文件，输出al为空，先谢谢各位了

public ArrayList<String> loadFromSDFile(String fname) {
fname="/"+fname;
String result=null;
ArrayList<String> al = new ArrayList<>();
try {
File sdCard = Environment.getExternalStorageDirectory();
File directory_Download = new File(sdCard, "Download");
System.out.println("directory_Download --- " + directory_Download);
File f = new File(directory_Download.getPath() + fname);
InputStreamReader in = new InputStreamReader(fin);
FileReader reader = new FileReader(f);
BufferedReader br = new BufferedReader(in);
String line = "";

while ((line = br.readLine()) != null) {
System.out.println("line --- " + line);
al.add(line);
}
}catch (Exception e){
e.printStackTrace();
//Toast.makeText(MainActivity.this,"没有找到指定文件",Toast.LENGTH_SHORT).show();
}
System.out.println("al --- " + al);
return al;
}

[王能]

这种问题，debug打个断点单步调试，分分钟就解决了