我无法在 Android Nougat 中获取根路径 USB otg，直到棉花糖为止正常工作。甚至能够获得SD卡的根路径。任何人都可以帮助我摆脱这个困境，这几天我很沮丧。
这是我的代码，返回棉花糖和牛轧糖SD卡的根路径。但不是 USB otg
public static String FileSystem() {
String path = null;
String SD_CARD_DIR = null;
try {
Process mount = Runtime.getRuntime().exec("mount");
BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(mount.getInputStream()));
mount.waitFor();
// String extPath = Environment.getExternalStorageDirectory().getPath();
// String isMedai = Environment.getExternalStorageState();
// if(Environment.MEDIA_MOUNTED.equalsIgnoreCase(isMedai)){
// String root = Environment.getRootDirectory().getPath();
// path = Environment.getExternalStoragePublicDirectory(DIRECTORY_EDUCOMP).getPath();
// }
String line;
String strFileSystem = null;
while ((line = bufferedReader.readLine()) != null) {
String[] split = line.split("\\s+");
for (int i = 0; i < split.length - 1; i++) {
if (SD_CARD_DIR == null) {
File mainroot = new File(split[i]);
File f[] = mainroot.listFiles(new FilenameFilter() {
@Override
public boolean accept(File dir, String name) {
return new File(dir, name).isDirectory();
}
}); // Get First level folders /mnt
if (f != null) {
for (File aFile : f) {
File[] filenames = aFile.listFiles(); // Get second level
// folders
// /mnt/sdcard so on
// and math Educomp
// folder
if (filenames != null) {
for (File ff : filenames) {
String eduFileName = ff.getName();
if (eduFileName.equals("Temp")) {
File[] listEducompfile = ff.listFiles();
if (listEducompfile != null) {
for (File fff : listEducompfile) {
String contentFileName = fff.getName();
if (contentFileName.equals("ts")) {
SD_CARD_DIR = aFile
.getAbsolutePath() + "/";
break;
}
}
}
} else {
File[] filenamesList = ff.listFiles(new FilenameFilter() {
@Override
public boolean accept(File dir, String name) {
return new File(dir, name).isDirectory();
}
});
if (filenamesList != null) {
for (File fff : filenamesList) {
String eduFileNamess = fff.getName();
if (eduFileNamess.equals("Temp")) {
File[] listEducompfile = fff.listFiles();
if (listEducompfile != null) {
for (File fffds : listEducompfile) {
String contentFileName = fffds.getName();
if (contentFileName.equals("ts")) {
return SD_CARD_DIR = ff + "/";
}
}
}
}
}
}
}
}
}
}
}
}
// SD_CARD_DIR = DEFAULT_SD_CARD_DIR;
}
return SD_CARD_DIR;
}
return path;
} catch (IOException e) {
e.printStackTrace();
} catch (InterruptedException e) {
e.printStackTrace();
}
return null;
}
最佳答案
File dir = new File ("/");
File files = dir.listFiles();
您不会在 Nougat 中获得根目录的列表。你本可以告诉我们这一点。
`files==null` or files.length()==0
Nougat 不允许列出根目录。还有其他几个目录，您无法在 Nougat 下列出。
关于java - 我无法在 Android Nougat 中获取 USB otg 的根路径。但能够获取 sd 卡的根路径，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/44174460/