How to send a websocket GPS message from an Android device to a server?
I am using React Native. When tested on the emulator, the GPS value is transmitted normally through the websocket, but when tested on an actual Android device, the value is not transmitted.

When running the app, the location information permission confirmation notification appears normally, but the value is not transmitted from the device to the server.

My Android manifest code is as follows.

<manifest xmlns:android="http://schemas.android.com/apk/res/android">

    <uses-permission android:name="android.permission.INTERNET" />
    <uses-permission android:name="android.permission.ACCESS_FINE_LOCATION" />
    <uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION" />

    <application
      android:name=".MainApplication"
      android:label="@string/app_name"
      android:icon="@mipmap/ic_launcher"
      android:roundIcon="@mipmap/ic_launcher_round"
      android:allowBackup="false"
      android:theme="@style/AppTheme">
      <activity
        android:name=".MainActivity"
        android:label="@string/app_name"
        android:configChanges="keyboard|keyboardHidden|orientation|screenLayout|screenSize|smallestScreenSize|uiMode"
        android:launchMode="singleTask"
        android:windowSoftInputMode="adjustResize"
        android:exported="true">
        <intent-filter>
            <action android:name="android.intent.action.MAIN" />
            <category android:name="android.intent.category.LAUNCHER" />
        </intent-filter>
      </activity>
    </application>
</manifest>

The following is IdCardScreen.js, which transmits gps values ​​through websocket.

import React, { useState, useEffect } from 'react';
import { StyleSheet, Text, View, PermissionsAndroid, Platform } from 'react-native';
import Geolocation from '@react-native-community/geolocation';
import { useRoute } from '@react-navigation/native';

const GeoLocationAPI = () => {
    const route = useRoute();
    const { userId, phoneNumber, adminName, institutionName } = route.params;

    const [latitude, setLatitude] = useState(null);
    const [longitude, setLongitude] = useState(null);
    const [ws, setWs] = useState(null);

    // 위치 권한 요청 함수
    const requestLocationPermission = async () => {
        try {
            if (Platform.OS === 'android') {
                const granted = await PermissionsAndroid.request(
                    PermissionsAndroid.PERMISSIONS.ACCESS_FINE_LOCATION,
                    {
                        title: 'Location Permission',
                        message: 'This app needs to access your location.',
                        buttonPositive: 'OK',
                    },
                );
                if (granted === PermissionsAndroid.RESULTS.GRANTED) {
                    // 권한 허용되면 위치 정보 가져오기
                    geoLocation();
                } else {
                    console.log('Location permission denied.');
                }
            } else {
                // iOS에서는 이미 Info.plist에 권한을 설정했으므로 따로 처리할 필요 없음
                geoLocation();
            }
        } catch (err) {
            console.warn(err);
        }
    };

    // 위치 정보 가져오기 함수
    const geoLocation = async () => {
        Geolocation.getCurrentPosition(
            position => {
                const { latitude, longitude } = position.coords;
                setLatitude(latitude);
                setLongitude(longitude);
            },
            error => {
                console.log(error.code, error.message);
            },
            { enableHighAccuracy: true, timeout: 15000, maximumAge: 10000 },
        );
    };

    // WebSocket 연결 및 데이터 전송 함수
    useEffect(() => {
        const newWs = new WebSocket('URL'); // 새로운 WebSocket 인스턴스 생성
        // test server url
        // const newWs = new WebSocket('URL');
        // server url
        newWs.onopen = () => {
            console.log('Connected to WebSocket server');
            setWs(newWs); // ws 상태 변수 업데이트
        };

        newWs.onerror = (e) => {
            console.error('WebSocket error:', e.message);
        };

        // 컴포넌트가 언마운트될 때 WebSocket 연결 닫기
        return () => {
            newWs.close();
        };
    }, []);

    // 1초마다 위치 정보 전송
    useEffect(() => {
        const intervalId = setInterval(() => {
            if (latitude !== null && longitude !== null && ws !== null) {
                const locationData = {
                    userId: userId,
                    Location: `(${latitude}, ${longitude})`
                };
                ws.send(JSON.stringify(locationData));
            }
        }, 1000);

        // 컴포넌트가 언마운트될 때 인터벌 클리어
        return () => clearInterval(intervalId);
    }, [latitude, longitude, ws]);

    // 페이지 로드 시 위치 권한 요청
    useEffect(() => {
        requestLocationPermission();
    }, []);

    return (
        <View style={styles.container}>
            <View style={styles.infoCard}>
                <Text style={styles.cardTitle}>인솔자 정보</Text>
                <Text style={styles.cardText}>인솔자 이름: {adminName}</Text>
                <Text style={styles.cardText}>인솔자 번호: {phoneNumber}</Text>
                <Text style={styles.cardText}>소속 기관: {institutionName}</Text>
            </View>
        </View>
    );
};

const styles = StyleSheet.create({
    container: {
        flex: 1,
        alignItems: 'center',
        justifyContent: 'center',
    },
    infoCard: {
        backgroundColor: '#fff',
        padding: 20,
        borderRadius: 10,
        shadowColor: '#000',
        shadowOffset: {
            width: 0,
            height: 2,
        },
        shadowOpacity: 0.25,
        shadowRadius: 3.84,
        elevation: 5,
        marginBottom: 20,
        alignItems: 'center', // 수평 가운데 정렬
    },
    cardTitle: {
        fontSize: 24,
        fontWeight: 'bold',
        marginBottom: 10,
    },
    cardText: {
        fontSize: 18,
        marginBottom: 10,
    },
});

export default GeoLocationAPI;