Android常用的

 1 /**
 2      * @return return true when the phone's SD card is available; Otherwise return false.
 3      */
 4     public static boolean hasSDCard() {
 5         return Environment.getExternalStorageState().equals(Environment.MEDIA_MOUNTED);
 6     }
 7     
 8     /**
 9      * @return return true when the phone's SD card is available and has enough space; Otherwise return false.
10      */
11     public static boolean hasSpace() {
12         if (!hasSDCard()) {
13             return false;
14         }
15         File path = Environment.getExternalStorageDirectory();
16         StatFs statFs = new StatFs(path.getPath());
17         
18         int blockSize = statFs.getBlockSize();
19         long availableBlock = statFs.getAvailableBlocks();        
20         long spareSize = blockSize * availableBlock;
21 
22         return spareSize >= Constants.SDCARD_MIN_SPARE_SIZE;
23     }