DIRECTORY_ALARMS //警报的铃声
DIRECTORY_DCIM //相机拍摄的图片和视频保存的位置
DIRECTORY_DOWNLOADS //下载文件保存的位置
DIRECTORY_MOVIES //电影保存的位置， 比如 通过google play下载的电影
DIRECTORY_MUSIC //音乐保存的位置
DIRECTORY_NOTIFICATIONS //通知音保存的位置
DIRECTORY_PICTURES //下载的图片保存的位置
DIRECTORY_PODCASTS //用于保存podcast(博客)的音频文件
DIRECTORY_RINGTONES //保存铃声的位置

package ckl.storage.list;

import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
import android.app.Activity;
import android.os.storage.StorageManager;

public class StorageList {
private Activity mActivity;
private StorageManager mStorageManager;
private Method mMethodGetPaths;

public StorageList(Activity activity) {
mActivity = activity;
if (mActivity != null) {
mStorageManager = (StorageManager)mActivity
.getSystemService(Activity.STORAGE_SERVICE);
try {
mMethodGetPaths = mStorageManager.getClass()
.getMethod("getVolumePaths");
} catch (NoSuchMethodException e) {
e.printStackTrace();
}
}
}

public String[] getVolumePaths() {
String[] paths = null;
try {
paths = (String[]) mMethodGetPaths.invoke(mStorageManager);
} catch (IllegalArgumentException e) {
e.printStackTrace();
} catch (IllegalAccessException e) {
e.printStackTrace();
} catch (InvocationTargetException e) {
e.printStackTrace();
}
return paths;
}
}

if(Environment.getExternalStorageState().equals(Environment.MEDIA_MOUNTED))
{
//为true的话，内置sd卡存在
}

if(Environment.getStorageState(Environment.STORAGE_PATH_SD2).equals(Environment.MEDIA_MOUNTED))
{
//为true的话，外置sd卡存在
}

File sdcardDir = Environment.getExternalStorageDirectory();
StatFs sf = new StatFs(sdcardDir.getPath()); 
//sdcardDir.getPath())值为/mnt/sdcard，想取外置sd卡大小的话，直接代入/mnt/sdcard2
long blockSize = sf.getBlockSize(); //总大小
long blockCount = sf.getBlockCount();
long availCount = sf.getAvailableBlocks(); //有效大小