安卓工具類------)SD卡相關的輔助類

import java.io.File;

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

//SD卡相關的輔助類
public class SDCardUtils
{
	private SDCardUtils()
	{
		/* cannot be instantiated */
		throw new UnsupportedOperationException("cannot be instantiated");
	}

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

	}

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

	/**
	 * 獲取SD卡的剩余容量 單位byte
	 * 
	 * @return
	 */
	public static long getSDCardAllSize()
	{
		if (isSDCardEnable())
		{
			StatFs stat = new StatFs(getSDCardPath());
			// 獲取空閒的數據塊的數量
			long availableBlocks = (long) stat.getAvailableBlocks() - 4;
			// 獲取單個數據塊的大小（byte）
			long freeBlocks = stat.getAvailableBlocks();
			return freeBlocks * availableBlocks;
		}
		return 0;
	}

	/**
	 * 獲取指定路徑所在空間的剩余可用容量字節數，單位byte
	 * 
	 * @param filePath
	 * @return 容量字節 SDCard可用空間，內部存儲可用空間
	 */
	public static long getFreeBytes(String filePath)
	{
		// 如果是sd卡的下的路徑，則獲取sd卡可用容量
		if (filePath.startsWith(getSDCardPath()))
		{
			filePath = getSDCardPath();
		} else
		{// 如果是內部存儲的路徑，則獲取內存存儲的可用容量
			filePath = Environment.getDataDirectory().getAbsolutePath();
		}
		StatFs stat = new StatFs(filePath);
		long availableBlocks = (long) stat.getAvailableBlocks() - 4;
		return stat.getBlockSize() * availableBlocks;
	}

	/**
	 * 獲取系統存儲路徑
	 * 
	 * @return
	 */
	public static String getRootDirectoryPath()
	{
		return Environment.getRootDirectory().getAbsolutePath();
	}


}