StorageUtils.java

package com.door43.util;

import android.os.Environment;

import java.io.BufferedReader;
import java.io.FileNotFoundException;
import java.io.FileReader;
import java.io.IOException;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.HashSet;
import java.util.List;
import java.util.StringTokenizer;

/**
 * This class provides utilites for determine what storage is available to the app.
 * This is nessesary because android will not reliably determine the sd card.
 * see http://stackoverflow.com/questions/9340332/how-can-i-get-the-list-of-mounted-external-storage-of-android-device
 *
 */
public class StorageUtils {

    private static final String TAG = "StorageUtils";

    public static class StorageInfo {

        public final String path;
        public final boolean readonly;
        public final boolean removable;
        public final int number;

        StorageInfo(String path, boolean readonly, boolean removable, int number) {
            this.path = path;
            this.readonly = readonly;
            this.removable = removable;
            this.number = number;
        }

        public String getDisplayName() {
            StringBuilder res = new StringBuilder();
            if (!removable) {
                res.append("Internal SD card");
            } else if (number > 1) {
                res.append("SD card " + number);
            } else {
                res.append("SD card");
            }
            if (readonly) {
                res.append(" (Read only)");
            }
            return res.toString();
        }

        /**
         * Returns the name of the mount directory
         * @return
         */
        public String getMountName() {
            String pieces[] = path.split("/");
            return pieces[pieces.length-1];
        }
    }

    public static List<StorageInfo> getStorageList() {

        List<StorageInfo> list = new ArrayList<StorageInfo>();
        String def_path = Environment.getExternalStorageDirectory().getPath();
        boolean def_path_removable = 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);

        HashSet<String> paths = new HashSet<String>();
        int cur_removable_number = 1;

        if (def_path_available) {
            paths.add(def_path);
            list.add(0, new StorageInfo(def_path, def_path_readonly, def_path_removable, def_path_removable ? cur_removable_number++ : -1));
        }

        BufferedReader buf_reader = null;
        try {
            buf_reader = new BufferedReader(new FileReader("/proc/mounts"));
            String line;
            while ((line = buf_reader.readLine()) != null) {
                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 (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, readonly, true, cur_removable_number++));
                        }
                    }
                }
            }

        } catch (FileNotFoundException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        } finally {
            if (buf_reader != null) {
                try {
                    buf_reader.close();
                } catch (IOException ex) {}
            }
        }
        return list;
    }

    /**
     * Returns the storage info for the removeable media if it exists
     * @return
     */
    public static StorageInfo getRemoveableMediaDevice() {
        return getMountDevice("sdcard1");
    }

    /**
     * Returns storage info for a mount device
     * @param name the name of the mount device
     * @return
     */
    public static StorageInfo getMountDevice(String name) {
        List<StorageUtils.StorageInfo> storageList = getStorageList();
        for(StorageUtils.StorageInfo info:storageList) {
            if(info.removable && info.getMountName().equals(name)) {
                return info;
            }
        }
        return null;
    }
}