androidstudio安卓获取外部sd卡存储

private static String getStoragePath(Context mContext, boolean is_removale) {

    StorageManager mStorageManager = (StorageManager) mContext.getSystemService(Context.STORAGE_SERVICE);
    Class<?> storageVolumeClazz = null;
    try {
        storageVolumeClazz = Class.forName("android.os.storage.StorageVolume");
        Method getVolumeList = mStorageManager.getClass().getMethod("getVolumeList");
        Method getPath = storageVolumeClazz.getMethod("getPath");
        Method isRemovable = storageVolumeClazz.getMethod("isRemovable");
        Object result = getVolumeList.invoke(mStorageManager);
        final int length = Array.getLength(result);
        for (int i = 0; i < length; i++) {
            Object storageVolumeElement = Array.get(result, i);
            String path = null;
            try {
                path = (String) getPath.invoke(storageVolumeElement);
            } catch (InvocationTargetException e) {
                e.printStackTrace();
            }
            boolean removable = (Boolean) isRemovable.invoke(storageVolumeElement);
            if (is_removale == removable) {
                return path;
            }
        }
    } catch (ClassNotFoundException e) {
        e.printStackTrace();
    } catch (InvocationTargetException e) {
        e.printStackTrace();
    } catch (NoSuchMethodException e) {
        e.printStackTrace();
    } catch (IllegalAccessException e) {
        e.printStackTrace();
    }
    return null;
}

/**
 * 6.0使用此方法获取外置SD卡路径，尝试过反射{@link StorageManager#getVolumeList}
 * 但StorageVolume非Public API 编译不通过（7.0改为公开API）,故使用UserEnvironment
 * 的内部方法getExternalDirs获取所有的路径，通过{@link Environment#isExternalStorageRemovable(File)}
 * 判断若removable则为外部存储
 */
@TargetApi(Build.VERSION_CODES.LOLLIPOP)
//@RequiresApi(api = Build.VERSION_CODES.LOLLIPOP)
private static String getPhysicalExternalFilePathAboveM(){
    try {
        //===========================获取UserEnvironment================
        Class<?> userEnvironment = Class.forName("android.os.Environment$UserEnvironment");
        Method getExternalDirs =userEnvironment.getDeclaredMethod("getExternalDirs");
        getExternalDirs.setAccessible(true);
        //========获取构造UserEnvironment的必要参数UserId================
        Class<?> userHandle = Class.forName("android.os.UserHandle");
        Method myUserId = userHandle.getDeclaredMethod("myUserId");
        myUserId.setAccessible(true);
        int mUserId = (int) myUserId.invoke(UserHandle.class);
        Constructor<?> declaredConstructor = userEnvironment.getDeclaredConstructor(Integer.TYPE);
        // 得到UserEnvironment instance
        Object instance = declaredConstructor.newInstance(mUserId);
        File[] files = (File[]) getExternalDirs.invoke(instance);
        for (int i = 0; i < files.length; i++) {
            if (Environment.isExternalStorageRemovable(files[i])){
                return files[i].getPath();
            }
        }
    } catch (Exception e) {

    }
    return "";
}

使用sd卡权限前请求权限

    public void getPermissions(){
        if (Build.VERSION.SDK_INT >= 23) {
            int REQUEST_CODE_PERMISSION_STORAGE = 100;
            String[] permissions = {
                    Manifest.permission.READ_EXTERNAL_STORAGE,
                    Manifest.permission.WRITE_EXTERNAL_STORAGE//, "android.permission.WRITE_MEDIA_STORAGE"
            };

            this.requestPermissions(permissions,REQUEST_CODE_PERMISSION_STORAGE);

//            for (String str : permissions) {
//                if (this.checkSelfPermission(str) != PackageManager.PERMISSION_GRANTED) {
//                    this.requestPermissions(permissions, REQUEST_CODE_PERMISSION_STORAGE);
//                    return;
//                }
//            }
        }
    }