在android studio上使用batterymanager需要帮助

import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.content.IntentFilter;
import android.os.BatteryManager;
import android.os.Bundle;
import android.widget.TextView;
import androidx.appcompat.app.AppCompatActivity;

public class MainActivity extends AppCompatActivity {

    private TextView batteryInfoTextView;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        batteryInfoTextView = findViewById(R.id.batteryInfoTextView);

        // 注册电池状态变化的广播接收器
        IntentFilter filter = new IntentFilter(Intent.ACTION_BATTERY_CHANGED);
        registerReceiver(batteryInfoReceiver, filter);
    }

    private final BroadcastReceiver batteryInfoReceiver = new BroadcastReceiver() {
        @Override
        public void onReceive(Context context, Intent intent) {
            int status = intent.getIntExtra(BatteryManager.EXTRA_STATUS, -1);
            int level = intent.getIntExtra(BatteryManager.EXTRA_LEVEL, -1);
            int scale = intent.getIntExtra(BatteryManager.EXTRA_SCALE, -1);

            String batteryStatus;
            switch (status) {
                case BatteryManager.BATTERY_STATUS_CHARGING:
                    batteryStatus = "Charging";
                    break;
                case BatteryManager.BATTERY_STATUS_DISCHARGING:
                    batteryStatus = "Discharging";
                    break;
                case BatteryManager.BATTERY_STATUS_NOT_CHARGING:
                    batteryStatus = "Not Charging";
                    break;
                case BatteryManager.BATTERY_STATUS_FULL:
                    batteryStatus = "Full";
                    break;
                default:
                    batteryStatus = "Unknown";
                    break;
            }

            int batteryPct = (int) ((level / (float) scale) * 100);

            batteryInfoTextView.setText("Battery Status: " + batteryStatus + "\nBattery Level: " + batteryPct + "%");
        }
    };

    @Override
    protected void onDestroy() {
        super.onDestroy();
        // 取消注册广播接收器
        unregisterReceiver(batteryInfoReceiver);
    }
}