我试图通过使用下面给出的外部存储路径检查设备是否具有外部存储
if (new File("/ext_card/").exists()) {
specialPath = "/ext_card/";
} else if (new File("/mnt/sdcard/external_sd/").exists()) {
specialPath = "/mnt/sdcard/external_sd/";
} else if (new File("/storage/extSdCard/").exists()) {
specialPath = "/storage/extSdCard/";
} else if (new File("/mnt/extSdCard/").exists()) {
specialPath = "/mnt/extSdCard/";
} else if (new File("/mnt/sdcard/external_sd/").exists()) {
specialPath = "/mnt/sdcard/external_sd/";
} else if (new File("storage/sdcard1/").exists()) {
specialPath = "storage/sdcard1/";
}
但是在棉花糖中我找不到这条路径并且在使用ES FILEMANAGER进行检查时，他们在Moto G第3代中提供了类似存储/ 3263-3131。在检查其他棉花糖设备时，数字会有所不同。请帮我检查棉花糖设备是否有外部存储？如果找到存储意味着如何获取该外部存储的路径？
注意： - 我在我的应用程序中授予了存储权限，并在我的应用程序的设置中启用了存储权限。
提前致谢，你在我的问题中发现任何错误请crt它。再次感谢你。
答案 0 :(得分：17)
这是我的解决方案，保证可以使用到Android 7.0 Nougat：
/* returns external storage paths (directory of external memory card) as array of Strings */
public String[] getExternalStorageDirectories() {
List<String> results = new ArrayList<>();
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.KITKAT) { //Method 1 for KitKat & above
File[] externalDirs = getExternalFilesDirs(null);
String internalRoot = Environment.getExternalStorageDirectory().getAbsolutePath().toLowerCase();
for (File file : externalDirs) {
if(file==null) //solved NPE on some Lollipop devices
continue;
String path = file.getPath().split("/Android")[0];
if(path.toLowerCase().startsWith(internalRoot))
continue;
boolean addPath = false;
if(Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP) {
addPath = Environment.isExternalStorageRemovable(file);
}
else{
addPath = Environment.MEDIA_MOUNTED.equals(EnvironmentCompat.getStorageState(file));
}
if(addPath){
results.add(path);
}
}
}
if(results.isEmpty()) { //Method 2 for all versions
// better variation of: http://stackoverflow.com/a/40123073/5002496
String output = "";
try {
final Process process = new ProcessBuilder().command("mount | grep /dev/block/vold")
.redirectErrorStream(true).start();
process.waitFor();
final InputStream is = process.getInputStream();
final byte[] buffer = new byte[1024];
while (is.read(buffer) != -1) {
output = output + new String(buffer);
}
is.close();
} catch (final Exception e) {
e.printStackTrace();
}
if(!output.trim().isEmpty()) {
String devicePoints[] = output.split("\n");
for(String voldPoint: devicePoints) {
results.add(voldPoint.split(" ")[2]);
}
}
}
//Below few lines is to remove paths which may not be external memory card, like OTG (feel free to comment them out)
if(Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {
for (int i = 0; i < results.size(); i++) {
if (!results.get(i).toLowerCase().matches(".*[0-9a-f]{4}[-][0-9a-f]{4}")) {
Log.d(LOG_TAG, results.get(i) + " might not be extSDcard");
results.remove(i--);
}
}
} else {
for (int i = 0; i < results.size(); i++) {
if (!results.get(i).toLowerCase().contains("ext") && !results.get(i).toLowerCase().contains("sdcard")) {
Log.d(LOG_TAG, results.get(i)+" might not be extSDcard");
results.remove(i--);
}
}
}
String[] storageDirectories = new String[results.size()];
for(int i=0; i<results.size(); ++i) storageDirectories[i] = results.get(i);
return storageDirectories;
}
答案 1 :(得分：3)
我在这里找到了解决方案https://stackoverflow.com/a/13648873/842607
代码是 -
public static HashSet<String> getExternalMounts() {
final HashSet<String> out = new HashSet<String>();
String reg = "(?i).*vold.*(vfat|ntfs|exfat|fat32|ext3|ext4).*rw.*";
String s = "";
try {
final Process process = new ProcessBuilder().command("mount")
.redirectErrorStream(true).start();
process.waitFor();
final InputStream is = process.getInputStream();
final byte[] buffer = new byte[1024];
while (is.read(buffer) != -1) {
s = s + new String(buffer);
}
is.close();
} catch (final Exception e) {
e.printStackTrace();
}
// parse output
final String[] lines = s.split("\n");
for (String line : lines) {
if (!line.toLowerCase(Locale.US).contains("asec")) {
if (line.matches(reg)) {
String[] parts = line.split(" ");
for (String part : parts) {
if (part.startsWith("/"))
if (!part.toLowerCase(Locale.US).contains("vold"))
out.add(part);
}
}
}
}
return out;
}
另一个是我从同一页面找到的黑客 -
private static final Pattern DIR_SEPORATOR = Pattern.compile("/");
/**
* Raturns all available SD-Cards in the system (include emulated)
*
* Warning: Hack! Based on Android source code of version 4.3 (API 18)
* Because there is no standart way to get it.
* TODO: Test on future Android versions 4.4+
*
* @return paths to all available SD-Cards in the system (include emulated)
*/
public static String[] getStorageDirectories()
{
// Final set of paths
final Set<String> rv = new HashSet<String>();
// Primary physical SD-CARD (not emulated)
final String rawExternalStorage = System.getenv("EXTERNAL_STORAGE");
// All Secondary SD-CARDs (all exclude primary) separated by ":"
final String rawSecondaryStoragesStr = System.getenv("SECONDARY_STORAGE");
// Primary emulated SD-CARD
final String rawEmulatedStorageTarget = System.getenv("EMULATED_STORAGE_TARGET");
if(TextUtils.isEmpty(rawEmulatedStorageTarget))
{
// Device has physical external storage; use plain paths.
if(TextUtils.isEmpty(rawExternalStorage))
{
// EXTERNAL_STORAGE undefined; falling back to default.
rv.add("/storage/sdcard0");
}
else
{
rv.add(rawExternalStorage);
}
}
else
{
// Device has emulated storage; external storage paths should have
// userId burned into them.
final String rawUserId;
if(Build.VERSION.SDK_INT < Build.VERSION_CODES.JELLY_BEAN_MR1)
{
rawUserId = "";
}
else
{
final String path = Environment.getExternalStorageDirectory().getAbsolutePath();
final String[] folders = DIR_SEPORATOR.split(path);
final String lastFolder = folders[folders.length - 1];
boolean isDigit = false;
try
{
Integer.valueOf(lastFolder);
isDigit = true;
}
catch(NumberFormatException ignored)
{
}
rawUserId = isDigit ? lastFolder : "";
}
// /storage/emulated/0[1,2,...]
if(TextUtils.isEmpty(rawUserId))
{
rv.add(rawEmulatedStorageTarget);
}
else
{
rv.add(rawEmulatedStorageTarget + File.separator + rawUserId);
}
}
// Add all secondary storages
if(!TextUtils.isEmpty(rawSecondaryStoragesStr))
{
// All Secondary SD-CARDs splited into array
final String[] rawSecondaryStorages = rawSecondaryStoragesStr.split(File.pathSeparator);
Collections.addAll(rv, rawSecondaryStorages);
}
return rv.toArray(new String[rv.size()]);
}
答案 2 :(得分：1)
这个图书馆解决了我的问题。
https://github.com/hendrawd/StorageUtil
我所做的是：
private File directory;
String[] allPath;
allPath = StorageUtil.getStorageDirectories(this);
for (String path: allPath){
directory = new File(path);
Methods.update_Directory_Files(directory);
}
Methods.update_Directory_Files（）
// Retrieving files from memory
public static void update_Directory_Files(File directory) {
//Get all file in storage
File[] fileList = directory.listFiles();
//check storage is empty or not
if(fileList != null && fileList.length > 0)
{
for (int i=0; i<fileList.length; i++)
{
boolean restricted_directory = false;
//check file is directory or other file
if(fileList[i].isDirectory())
{
for (String path : Constant.removePath){
if (path.equals(fileList[i].getPath())) {
restricted_directory = true;
break;
}
}
if (!restricted_directory)
update_Directory_Files(fileList[i]);
}
else
{
String name = fileList[i].getName().toLowerCase();
for (String ext : Constant.videoExtensions){
//Check the type of file
if(name.endsWith(ext))
{
//first getVideoDuration
String videoDuration = Methods.getVideoDuration(fileList[i]);
long playbackPosition;
long percentage = C.TIME_UNSET;
FilesInfo.fileState state;
/*First check video already played or not. If not then state is NEW
* else load playback position and calculate percentage of it and assign it*/
//check it if already exist or not if yes then start from there else start from start position
int existIndex = -1;
for (int j = 0; j < Constant.filesPlaybackHistory.size(); j++) {
String fListName = fileList[i].getName();
String fPlaybackHisName = Constant.filesPlaybackHistory.get(j).getFileName();
if (fListName.equals(fPlaybackHisName)) {
existIndex = j;
break;
}
}
try {
if (existIndex != -1) {
//if true that means file is not new
state = FilesInfo.fileState.NOT_NEW;
//set playbackPercentage not playbackPosition
MediaMetadataRetriever retriever = new MediaMetadataRetriever();
retriever.setDataSource(fileList[i].getPath());
String time = retriever.extractMetadata(MediaMetadataRetriever.METADATA_KEY_DURATION);
retriever.release();
int duration = Integer.parseInt(time);
playbackPosition = Constant.filesPlaybackHistory.get(existIndex).getPlaybackPosition();
if (duration > 0)
percentage = 1000L * playbackPosition / duration;
else
percentage = C.TIME_UNSET;
}
else
state = FilesInfo.fileState.NEW;
//playbackPosition have value in percentage
Constant.allMemoryVideoList.add(new FilesInfo(fileList[i],
directory,videoDuration, state, percentage));
//directory portion
currentDirectory = directory.getPath();
unique_directory = true;
for(int j=0; j<directoryList.size(); j++)
{
if((directoryList.get(j).toString()).equals(currentDirectory)){
unique_directory = false;
}
}
if(unique_directory){
directoryList.add(directory);
}
//When we found extension from videoExtension array we will break it.
break;
}catch (Exception e){
e.printStackTrace();
Constant.allMemoryVideoList.add(new FilesInfo(fileList[i],
directory,videoDuration, FilesInfo.fileState.NOT_NEW, C.TIME_UNSET));
}
}
}
}
}
}
Constant.directoryList = directoryList;
}
答案 3 :(得分：0)
在这里我有redmi note prime 2.我没有记忆卡。所以当我找到路径和File [] externalDirs = getExternalFilesDirs（null）;给出文件[]的第二个postion值。 }