Android——SD卡工具类——SDCardUtils.java

 package com.xdsjs.save.utils;

 /**
  * SD卡相关的辅助类
  * Created by xdsjs on 2015/10/13.
  */

 import java.io.File;

 import android.os.Environment;
 import android.os.StatFs;

 public class SDCardUtils {
     private SDCardUtils() {
         /* cannot be instantiated */
         throw new UnsupportedOperationException("cannot be instantiated");
     }

     /**
      * 判断SDCard是否可用
      *
      * @return
      */
     public static boolean isSDCardEnable() {
         return Environment.getExternalStorageState().equals(
                 Environment.MEDIA_MOUNTED);

     }

     /**
      * 获取SD卡路径
      *
      * @return
      */
     public static String getSDCardPath() {
         return Environment.getExternalStorageDirectory().getAbsolutePath()
                 + File.separator;
     }

     /**
      * 获取SD卡的剩余容量 单位byte
      *
      * @return
      */
     public static long getSDCardAllSize() {
         if (isSDCardEnable()) {
             StatFs stat = new StatFs(getSDCardPath());
             // 获取空闲的数据块的数量
             long availableBlocks = stat.getAvailableBlocks();
             // 获取单个数据块的大小（byte）
             long blockSize = stat.getBlockSize();
             return blockSize * availableBlocks;
         }
         return 0;
     }

     /**
      * 获取指定路径所在空间的剩余可用容量字节数，单位byte
      *
      * @param filePath
      * @return 容量字节 SDCard可用空间，内部存储可用空间
      */
     public static long getFreeBytes(String filePath) {
         // 如果是sd卡的下的路径，则获取sd卡可用容量
         if (filePath.startsWith(getSDCardPath())) {
             filePath = getSDCardPath();
         } else {// 如果是内部存储的路径，则获取内存存储的可用容量
             filePath = Environment.getDataDirectory().getAbsolutePath();
         }
         StatFs stat = new StatFs(filePath);
         long availableBlocks = (long) stat.getAvailableBlocks() - 4;
         return stat.getBlockSize() * availableBlocks;
     }

     /**
      * 获取系统存储路径
      *
      * @return
      */
     public static String getRootDirectoryPath() {
         return Environment.getRootDirectory().getAbsolutePath();
     }

 }