Android手机外置SD卡(TF卡)的获取方法

 1 public class SDCardScanner {
 2     /*
 3      * avoid initializations of tool classes
 4      */
 5     private SDCardScanner() {
 6     }
 7 
 8     /**
 9      * @Title: getExtSDCardPaths
10      * @Description: to obtain storage paths, the first path is theoretically
11      *               the returned value of
12      *               Environment.getExternalStorageDirectory(), namely the
13      *               primary external storage. It can be the storage of internal
14      *               device, or that of external sdcard. If paths.size() >1,
15      *               basically, the current device contains two type of storage:
16      *               one is the storage of the device itself, one is that of
17      *               external sdcard. Additionally, the paths is directory.
18      * @return List<String>
19      * @throws IOException
20      */
21     public static List<String> getExtSDCardPaths() {
22         List<String> paths = new ArrayList<String>();
23         String extFileStatus = Environment.getExternalStorageState();
24         File extFile = Environment.getExternalStorageDirectory();
25         if (extFileStatus.endsWith(Environment.MEDIA_UNMOUNTED)
26                 && extFile.exists() && extFile.isDirectory()
27                 && extFile.canWrite()) {
28             paths.add(extFile.getAbsolutePath());
29         }
30         try {
31             // obtain executed result of command line code of ‘mount‘, to judge
32             // whether tfCard exists by the result
33             Runtime runtime = Runtime.getRuntime();
34             Process process = runtime.exec("mount");
35             InputStream is = process.getInputStream();
36             InputStreamReader isr = new InputStreamReader(is);
37             BufferedReader br = new BufferedReader(isr);
38             String line = null;
39             int mountPathIndex = 1;
40             while ((line = br.readLine()) != null) {
41                 // format of sdcard file system: vfat/fuse
42                 if ((!line.contains("fat") && !line.contains("fuse") && !line
43                         .contains("storage"))
44                         || line.contains("secure")
45                         || line.contains("asec")
46                         || line.contains("firmware")
47                         || line.contains("shell")
48                         || line.contains("obb")
49                         || line.contains("legacy") || line.contains("data")) {
50                     continue;
51                 }
52                 String[] parts = line.split(" ");
53                 int length = parts.length;
54                 if (mountPathIndex >= length) {
55                     continue;
56                 }
57                 String mountPath = parts[mountPathIndex];
58                 if (!mountPath.contains("/") || mountPath.contains("data")
59                         || mountPath.contains("Data")) {
60                     continue;
61                 }
62                 File mountRoot = new File(mountPath);
63                 if (!mountRoot.exists() || !mountRoot.isDirectory()
64                         || !mountRoot.canWrite()) {
65                     continue;
66                 }
67                 boolean equalsToPrimarySD = mountPath.equals(extFile
68                         .getAbsolutePath());
69                 if (equalsToPrimarySD) {
70                     continue;
71                 }
72                 paths.add(mountPath);
73             }
74         } catch (IOException e) {
75             // TODO Auto-generated catch block
76             e.printStackTrace();
77         }
78         return paths;
79     }
80 }