获取系统所有文件集合

private Handler handler = new Handler(){

    @Override
    public void handleMessage(Message msg) {
        super.handleMessage(msg);
        
        adapter = new ArrayAdapter(MainActivity.this,android.R.layout.simple_list_item_1,list_s);
        mListView.setAdapter(adapter);
    }
};

final File dirFile = Environment.getRootDirectory();
new Thread(new Runnable() {
    @Override
    public void run() {
        ShowFile(dirFile);
        handler.sendEmptyMessage(0);
    }
}).start();

private void ShowFile(File dirFile){
    if(dirFile.exists()&&dirFile!=null){
        if(dirFile.isDirectory()&&dirFile!=null&&dirFile.listFiles()!=null){
            Log.i(TAG,"path is "+dirFile.getPath()+"\nlength = "+dirFile.length());
            for (File file:dirFile.listFiles()) {
                if(file.isDirectory()&&file!=null&&file.length()!=0){
                    ShowFile(file);
                }else{
                    list_s.add(file.getPath());
                }
            }
        }else{
            list_s.add(dirFile.getPath());
        }

    }
}