android - How to get SD_Card path in android6.0 programmatically

Question

I am trying to check whether device having external storage or not by using external storage path like this given below

 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/";
    }

But in marshmallow I con't find this path and while checking using ES FILEMANAGER, they give like storage/3263-3131 in Moto G 3rd generation. While check in other marshmallow devices that numbers getting differ. Please help me to check that marshmallow device have external storage or not? and if storage found means how to get the path of that external storage?

Note:- I gave permission for storage in my application and also enabled storage permission in settings for my app.

Thanks in advance and did you find any mistake in my question please crt it. thank you again.

Answer 1

Here's my solution, which is guaranteed to work till 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("
");
                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;
    }