反射获取储存的设备

//可以获取储存设备,包括U盘,此方法与adb通过storage获取的储存设备一致
public List<StorageInfo> listAllStorage(Context context) {
    ArrayList<StorageInfo> storages = new ArrayList<StorageInfo>();
    StorageManager storageManager = (StorageManager) context.getSystemService(Context.STORAGE_SERVICE);
    try {
        Class<?>[] paramClasses = {};
        Method getVolumeList = StorageManager.class.getMethod("getVolumeList", paramClasses);
        Object[] params = {};
        Object[] invokes = (Object[]) getVolumeList.invoke(storageManager, params);

        if (invokes != null) {
            StorageInfo info = null;
            for (int i = 0; i < invokes.length; i++) {
                Object obj = invokes[i];
                Method getPath = obj.getClass().getMethod("getPath", new Class[0]);
                String path = (String) getPath.invoke(obj, new Object[0]);
                info = new StorageInfo(path);

                Method getVolumeState = StorageManager.class.getMethod("getVolumeState", String.class);
                String state = (String) getVolumeState.invoke(storageManager, info.path);
                info.state = state;

                Method isRemovable = obj.getClass().getMethod("isRemovable", new Class[0]);
                info.isRemoveable = ((Boolean) isRemovable.invoke(obj, new Object[0])).booleanValue();
                storages.add(info);
            }
        }
    } catch (Exception e) {
        e.printStackTrace();
    }
    storages.trimToSize();
    return storages;
}

//获取可用的设备
public static List<StorageInfo> getAvaliableStorage(List<StorageInfo> infos){
    List<StorageInfo> storages = new ArrayList<StorageInfo>();
    for(StorageInfo info : infos){
        File file = new File(info.path);
        if ((file.exists()) && (file.isDirectory()) && (file.canWrite())) {
            if (info.isMounted()) {
                storages.add(info);
            }
        }
    }

    return storages;
}

public class StorageInfo {
    public String path;
    public String state;
    public boolean isRemoveable;
    public StorageInfo(String path) {
        this.path = path;
    }
    public boolean isMounted() {
        return "mounted".equals(state);
    }
    @Override
    public String toString() {
        return "StorageInfo [path=" + path + ", state=" + state
                + ", isRemoveable=" + isRemoveable + "]";
    }

}

//下面是简单使用上面的方法
    public int checkFileIsExsit() {
        List<StorageInfo> list = listAllStorage(m_context);
        for(StorageInfo info : list){
            //确认是否存在特定文件
           m_sFilePath = info.path + "/" + filename;
            MyLog.e("u盘路径: "+info.path + "/" + filename);
            if (fileIsExists(m_sFilePath)) {
                //Log.e(TAG, filePath + " is exists!");
                return 0;
            }
        }
        MyLog.e(m_sFilePath + " is not exists!");

    return -1;
}

private static boolean fileIsExists(String filepath){
    //Log.e(TAG, "file: " + filepath);
    try{
        File f = new File(filepath);
        if(!f.exists()){
            return false;
        }
    }catch (Exception e) {
        MyLog.e(filepath + " not exists!");
        return false;
    }
    return true;
}