要获取Android 13上连接到热点的设备列表，可以使用WifiManager来获取已连接到当前设备热点的设备信息。以下是一个Java代码示例：

import android.content.Context;
import android.net.wifi.WifiConfiguration;
import android.net.wifi.WifiInfo;
import android.net.wifi.WifiManager;

import java.util.ArrayList;
import java.util.List;

public class HotspotDeviceList {

    public static List getConnectedDevices(Context context) {
        List connectedDevices = new ArrayList<>();

        WifiManager wifiManager = (WifiManager) context.getSystemService(Context.WIFI_SERVICE);
        if (wifiManager != null) {
            WifiInfo wifiInfo = wifiManager.getConnectionInfo();
            if (wifiInfo != null) {
                String ssid = wifiInfo.getSSID();
                if (ssid != null) {
                    if (ssid.startsWith("\"") && ssid.endsWith("\"")) {
                        ssid = ssid.substring(1, ssid.length() - 1);
                    }
    
                    List wifiConfigurations = wifiManager.getConfiguredNetworks();
                    if (wifiConfigurations != null) {
                        for (WifiConfiguration wifiConfiguration : wifiConfigurations) {
                            if (wifiConfiguration.SSID != null && wifiConfiguration.SSID.equals("\"" + ssid + "\"")) {
                                String[] connectedDevicesMacAddresses = wifiConfiguration.bridgeMac;
                                if (connectedDevicesMacAddresses != null) {
                                    for (String macAddress : connectedDevicesMacAddresses) {
                                        connectedDevices.add(macAddress);
                                    }
                                }
                                break;
                            }
                        }
                    }
                }
            }
        }

        return connectedDevices;
    }
}

要使用此方法，只需在Activity或Fragment中调用getConnectedDevices()方法，并传递一个有效的Context参数。例如：

List connectedDevices = HotspotDeviceList.getConnectedDevices(getApplicationContext());
for (String macAddress : connectedDevices) {
    // 处理每个连接设备的操作
}

请注意，此代码示例假设您已获得适当的权限（例如，ACCESS_WIFI_STATE和ACCESS_NETWORK_STATE）以及热点已正确配置。