android:如何在sdcard中获取存储在文件夹中的文件的完整路径？

<uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE" />
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />

String folderName = "your_folder_name";
String fileName = "your_file_name";
String sdCardPath = Environment.getExternalStorageDirectory().getAbsolutePath();
String fullPath = sdCardPath + File.separator + folderName + File.separator + fileName;

File file = new File(fullPath);
FileInputStream fis = new FileInputStream(file);