帮我写一段Android代码，实现如下功能：检测userdata分区的大小，如果小于某个值，则提示用户系统空间不足无法写入

在Android中，你可以使用`StorageManager` API 来获取设备的存储信息，包括内部存储空间。以下是一个简单的示例代码片段，它检查userdata分区的可用空间，并在空间不足时显示一条通知：

import android.app.Notification;
import android.app.NotificationChannel;
import android.app.NotificationManager;
import android.content.Context;
import android.content.pm.PackageManager;
import android.os.Environment;
import android.util.Log;

public class StorageSpaceChecker {

    private static final String TAG = "StorageChecker";
    private static final int NOTIFICATION_ID = 1001;
    private static final int MIN_AVAILABLE_SPACE_GB = 5; // 设置最小可用空间为5GB

    private Context context;
    private NotificationManager notificationManager;

    public StorageSpaceChecker(Context context) {
        this.context = context;
        notificationManager = (NotificationManager) context.getSystemService(Context.NOTIFICATION_SERVICE);
    }

    public void checkAndNotify() {
        try {
            long totalSize = Environment.getDataDirectory().getAvailableSpace();
            float availableGb = totalSize / (1024 * 1024 * 1024); // 转换为GB

            if (availableGb < MIN_AVAILABLE_SPACE_GB) {
                Log.d(TAG, "Not enough storage space for userdata partition");
                createNotification("存储警告", "您的内部存储空间不足 (" + (availableGb) + "GB)，无法继续写入数据.");
            } else {
                Log.d(TAG, "Enough storage space for userdata partition");
            }
        } catch (Exception e) {
            Log.e(TAG, "Error checking storage space", e);
        }
    }

    private void createNotification(String title, String message) {
        NotificationChannel channel = new NotificationChannel(NOTIFICATION_ID, "Storage Channel", NotificationManager.IMPORTANCE_DEFAULT);
        channel.setDescription("存储空间警报");
        context.getApplicationContext().registerReceiver(new BroadcastReceiver() {
            @Override
            public void onReceive(Context context, Intent intent) {
                notificationManager.cancel(NOTIFICATION_ID);
            }
        }, new IntentFilter(Intent.ACTION_USER_PRESENT));
        notificationManager.createNotificationChannel(channel);

        Notification notification = new NotificationCompat.Builder(context, NOTIFICATION_ID)
                .setSmallIcon(R.drawable.ic_storage_full)
                .setContentTitle(title)
                .setContentText(message)
                .build();

        notification.flags |= Notification.FLAG_AUTO_CANCEL;
        notificationManager.notify(NOTIFICATION_ID, notification);
    }
}

// 使用该类时，在需要的地方创建并调用
public static void main(String[] args) {
    Context appContext = YourApplication.getAppContext(); // 替换为实际的上下文
    StorageSpaceChecker checker = new StorageSpaceChecker(appContext);
    checker.checkAndNotify();
}

这个代码会周期性地检查，并在满足条件时显示通知。注意，你需要在应用运行时请求访问存储权限。