有没有一种通用的方法来找到外置SD卡的位置?
请不要与外部存储混淆。
Environment.getExternalStorageState()返回内部SD挂载点的路径,例如/mnt/sdcard。但问题是关于外部SD的。我如何获得类似/mnt/sdcard/external_sd的路径(它可能因设备而异)?
我想我将以根据文件系统名称过滤mount命令的输出作为结束。但我不确定这种方式是否足够稳健。
有没有一种通用的方法来找到外置SD卡的位置?
请不要与外部存储混淆。
Environment.getExternalStorageState()返回内部SD挂载点的路径,例如/mnt/sdcard。但问题是关于外部SD的。我如何获得类似/mnt/sdcard/external_sd的路径(它可能因设备而异)?
我想我将以根据文件系统名称过滤mount命令的输出作为结束。但我不确定这种方式是否足够稳健。
当前回答
这就是我如何找到外部存储路径。
public static String getExternalStoragePath(Context context){
File[] f = ContextCompat.getExternalFilesDirs(context, null);
String internalPath = Environment.getExternalStorageDirectory().getAbsolutePath();
String excessive = "";
String externalPath = "";
for (File file : f) {
if (file.getAbsolutePath().startsWith(internalPath)) {
excessive = file.getAbsolutePath().replaceAll(internalPath, "");
}
}
for (File file : f) {
if (!file.getAbsolutePath().startsWith(excessive)) {
externalPath = file.getAbsolutePath().replaceAll(excessive, "");
}
}
return externalPath;
}
其他回答
我已经创建了一个utils方法来检查SD卡在设备上是否可用,并获得设备上的SD卡路径(如果可用)。
你可以复制2方法波纹到你的项目的类,你需要。这是所有。
public String isRemovableSDCardAvailable() {
final String FLAG = "mnt";
final String SECONDARY_STORAGE = System.getenv("SECONDARY_STORAGE");
final String EXTERNAL_STORAGE_DOCOMO = System.getenv("EXTERNAL_STORAGE_DOCOMO");
final String EXTERNAL_SDCARD_STORAGE = System.getenv("EXTERNAL_SDCARD_STORAGE");
final String EXTERNAL_SD_STORAGE = System.getenv("EXTERNAL_SD_STORAGE");
final String EXTERNAL_STORAGE = System.getenv("EXTERNAL_STORAGE");
Map<Integer, String> listEnvironmentVariableStoreSDCardRootDirectory = new HashMap<Integer, String>();
listEnvironmentVariableStoreSDCardRootDirectory.put(0, SECONDARY_STORAGE);
listEnvironmentVariableStoreSDCardRootDirectory.put(1, EXTERNAL_STORAGE_DOCOMO);
listEnvironmentVariableStoreSDCardRootDirectory.put(2, EXTERNAL_SDCARD_STORAGE);
listEnvironmentVariableStoreSDCardRootDirectory.put(3, EXTERNAL_SD_STORAGE);
listEnvironmentVariableStoreSDCardRootDirectory.put(4, EXTERNAL_STORAGE);
File externalStorageList[] = null;
if (android.os.Build.VERSION.SDK_INT >= android.os.Build.VERSION_CODES.KITKAT) {
externalStorageList = getContext().getExternalFilesDirs(null);
}
String directory = null;
int size = listEnvironmentVariableStoreSDCardRootDirectory.size();
for (int i = 0; i < size; i++) {
if (externalStorageList != null && externalStorageList.length > 1 && externalStorageList[1] != null)
directory = externalStorageList[1].getAbsolutePath();
else
directory = listEnvironmentVariableStoreSDCardRootDirectory.get(i);
directory = canCreateFile(directory);
if (directory != null && directory.length() != 0) {
if (i == size - 1) {
if (directory.contains(FLAG)) {
Log.e(getClass().getSimpleName(), "SD Card's directory: " + directory);
return directory;
} else {
return null;
}
}
Log.e(getClass().getSimpleName(), "SD Card's directory: " + directory);
return directory;
}
}
return null;
}
/**
* Check if can create file on given directory. Use this enclose with method
* {@link BeginScreenFragement#isRemovableSDCardAvailable()} to check sd
* card is available on device or not.
*
* @param directory
* @return
*/
public String canCreateFile(String directory) {
final String FILE_DIR = directory + File.separator + "hoang.txt";
File tempFlie = null;
try {
tempFlie = new File(FILE_DIR);
FileOutputStream fos = new FileOutputStream(tempFlie);
fos.write(new byte[1024]);
fos.flush();
fos.close();
Log.e(getClass().getSimpleName(), "Can write file on this directory: " + FILE_DIR);
} catch (Exception e) {
Log.e(getClass().getSimpleName(), "Write file error: " + e.getMessage());
return null;
} finally {
if (tempFlie != null && tempFlie.exists() && tempFlie.isFile()) {
// tempFlie.delete();
tempFlie = null;
}
}
return directory;
}
像Richard一样,我也使用/proc/mounts文件来获取可用的存储选项列表
public class StorageUtils {
private static final String TAG = "StorageUtils";
public static class StorageInfo {
public final String path;
public final boolean internal;
public final boolean readonly;
public final int display_number;
StorageInfo(String path, boolean internal, boolean readonly, int display_number) {
this.path = path;
this.internal = internal;
this.readonly = readonly;
this.display_number = display_number;
}
public String getDisplayName() {
StringBuilder res = new StringBuilder();
if (internal) {
res.append("Internal SD card");
} else if (display_number > 1) {
res.append("SD card " + display_number);
} else {
res.append("SD card");
}
if (readonly) {
res.append(" (Read only)");
}
return res.toString();
}
}
public static List<StorageInfo> getStorageList() {
List<StorageInfo> list = new ArrayList<StorageInfo>();
String def_path = Environment.getExternalStorageDirectory().getPath();
boolean def_path_internal = !Environment.isExternalStorageRemovable();
String def_path_state = Environment.getExternalStorageState();
boolean def_path_available = def_path_state.equals(Environment.MEDIA_MOUNTED)
|| def_path_state.equals(Environment.MEDIA_MOUNTED_READ_ONLY);
boolean def_path_readonly = Environment.getExternalStorageState().equals(Environment.MEDIA_MOUNTED_READ_ONLY);
BufferedReader buf_reader = null;
try {
HashSet<String> paths = new HashSet<String>();
buf_reader = new BufferedReader(new FileReader("/proc/mounts"));
String line;
int cur_display_number = 1;
Log.d(TAG, "/proc/mounts");
while ((line = buf_reader.readLine()) != null) {
Log.d(TAG, line);
if (line.contains("vfat") || line.contains("/mnt")) {
StringTokenizer tokens = new StringTokenizer(line, " ");
String unused = tokens.nextToken(); //device
String mount_point = tokens.nextToken(); //mount point
if (paths.contains(mount_point)) {
continue;
}
unused = tokens.nextToken(); //file system
List<String> flags = Arrays.asList(tokens.nextToken().split(",")); //flags
boolean readonly = flags.contains("ro");
if (mount_point.equals(def_path)) {
paths.add(def_path);
list.add(0, new StorageInfo(def_path, def_path_internal, readonly, -1));
} else if (line.contains("/dev/block/vold")) {
if (!line.contains("/mnt/secure")
&& !line.contains("/mnt/asec")
&& !line.contains("/mnt/obb")
&& !line.contains("/dev/mapper")
&& !line.contains("tmpfs")) {
paths.add(mount_point);
list.add(new StorageInfo(mount_point, false, readonly, cur_display_number++));
}
}
}
}
if (!paths.contains(def_path) && def_path_available) {
list.add(0, new StorageInfo(def_path, def_path_internal, def_path_readonly, -1));
}
} catch (FileNotFoundException ex) {
ex.printStackTrace();
} catch (IOException ex) {
ex.printStackTrace();
} finally {
if (buf_reader != null) {
try {
buf_reader.close();
} catch (IOException ex) {}
}
}
return list;
}
}
只要简单地使用这个:
String primary_sd = System.getenv("EXTERNAL_STORAGE");
if(primary_sd != null)
Log.i("EXTERNAL_STORAGE", primary_sd);
String secondary_sd = System.getenv("SECONDARY_STORAGE");
if(secondary_sd != null)
Log.i("SECONDARY_STORAGE", secondary_sd)
如果你看一下Android .os. environment的源代码,你会发现Android非常依赖环境变量作为路径。您可以使用“SECONDARY_STORAGE”环境变量来查找到可移动sd卡的路径。
/**
* Get a file using an environmental variable.
*
* @param variableName
* The Environment variable name.
* @param paths
* Any paths to the file if the Environment variable was not found.
* @return the File or {@code null} if the File could not be located.
*/
private static File getDirectory(String variableName, String... paths) {
String path = System.getenv(variableName);
if (!TextUtils.isEmpty(path)) {
if (path.contains(":")) {
for (String _path : path.split(":")) {
File file = new File(_path);
if (file.exists()) {
return file;
}
}
} else {
File file = new File(path);
if (file.exists()) {
return file;
}
}
}
if (paths != null && paths.length > 0) {
for (String _path : paths) {
File file = new File(_path);
if (file.exists()) {
return file;
}
}
}
return null;
}
使用示例:
public static final File REMOVABLE_STORAGE = getDirectory("SECONDARY_STORAGE");
我不知道为什么,但我需要在使用它之前在公共存储目录中创建的文件上调用. createnewfile()。在框架中,该方法的注释说它没有用。这是一个样本……
String myPath = Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_PODCASTS) + File. txt文件。separator +“我的目录”; final File myDir = new File(myypath); 尝试{ myDir.mkdirs (); } catch(异常ex) { 吐司。makeText(this, "error: " + ex.getMessage(), Toast.LENGTH_LONG).show(); }
String fname = "whatever";
File newFile = new File(myDir, fname);
Log.i(TAG, "File exists --> " + newFile.exists()) //will be false
try {
if (newFile.createNewFile()) {
//continue
} else {
Log.e(TAG, "error creating file");
}
} catch (Exception e) {
Log.e(TAG, e.toString());
}