如何以编程方式在android6.0中获取SD_Card路径

Question

我正在尝试使用下面给出的外部存储路径来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/";
    }

但在棉花糖中，我找不到这条路径，并且在使用 ES FILEMANAGER 检查时，它们在 Moto G 第三代中给出了类似 storage/3263-3131 的信息。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。

在此先感谢您是否在我的问题中发现任何错误，请 crt 。再次感谢。

Answer 1

这是我的解决方案，保证在 Android 7.0 Nougat 之前都可以使用：

/* 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;
    }

Answer 2

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 hack -

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()]);
}

Answer 3

这个库解决了我的问题。

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;
}

Answer 4

在这我有 redmi note prime 2.and 我没有存储卡。所以当我找到路径和 File[] externalDirs = getExternalFilesDirs(null);给出文件 [] 的空第二个位置值。 }