Android内存和SD卡工具类

package com.example.testandroid;    import java.io.File;  import android.os.Environment;  import android.os.StatFs;    public class StorageUtil {   private static final int ERROR = -1;   public static int save_dir = 1;     // 判断是否已经安装SD卡   public static boolean isSDCardExist() {    return android.os.Environment.getExternalStorageState().equals(      android.os.Environment.MEDIA_MOUNTED);   }     // 内存剩余空间   public static long getAvailableInternalMemorySize() {    File path = Environment.getDataDirectory();    StatFs stat = new StatFs(path.getPath());    long blockSize = stat.getBlockSize();    long availableBlocks = stat.getAvailableBlocks();    return availableBlocks * blockSize;   }     // 内存总空间   public static long getTotalInternalMemorySize() {    File path = Environment.getDataDirectory();    StatFs stat = new StatFs(path.getPath());    long blockSize = stat.getBlockSize();    long totalBlocks = stat.getBlockCount();    return totalBlocks * blockSize;   }     // SD卡剩余空间   public static long getAvailableExternalMemorySize() {    if (isSDCardExist()) {     File path = Environment.getExternalStorageDirectory();     StatFs stat = new StatFs(path.getPath());     long blockSize = stat.getBlockSize();     long availableBlocks = stat.getAvailableBlocks();     return availableBlocks * blockSize;    } else {     return ERROR;    }   }     // SD卡总空间   public static long getTotalExternalMemorySize() {    if (isSDCardExist()) {     File path = Environment.getExternalStorageDirectory();     StatFs stat = new StatFs(path.getPath());     long blockSize = stat.getBlockSize();     long totalBlocks = stat.getBlockCount();     return totalBlocks * blockSize;    } else {     return ERROR;    }   }     // 判断SD卡下external_sd文件夹的总大小   public static long getTotalExternal_SDMemorySize() {    if (isSDCardExist()) {     File path = Environment.getExternalStorageDirectory();     File externalSD = new File(path.getPath() + "/external_sd");     if (externalSD.exists() && externalSD.isDirectory()) {      StatFs stat = new StatFs(path.getPath() + "/external_sd");      long blockSize = stat.getBlockSize();      long totalBlocks = stat.getBlockCount();      if (getTotalExternalMemorySize() != -1       && getTotalExternalMemorySize() != totalBlocks* blockSize) {       return totalBlocks * blockSize;      } else {       return ERROR;      }     } else {      return ERROR;     }      } else {     return ERROR;    }   }     // 判断SD卡下external_sd文件夹的可用大小   public static long getAvailableExternal_SDMemorySize() {    if (isSDCardExist()) {     File path = Environment.getExternalStorageDirectory();     File externalSD = new File(path.getPath() + "/external_sd");     if (externalSD.exists() && externalSD.isDirectory()) {      StatFs stat = new StatFs(path.getPath() + "/external_sd");      long blockSize = stat.getBlockSize();      long availableBlocks = stat.getAvailableBlocks();      if (getAvailableExternalMemorySize() != -1       && getAvailableExternalMemorySize() != availableBlocks* blockSize) {       return availableBlocks * blockSize;      } else {       return ERROR;      }       } else {      return ERROR;     }      } else {     return ERROR;    }   }  }