基于自有后端实现Flutter推送通知的方案及设备ID获取咨询

核心实现思路 #

要实现自有后端直接推送，核心是获取平台专属推送令牌并同步到后端，再通过对应平台的官方推送API发送通知，流程如下：

1. 客户端向系统申请通知权限，获取推送令牌（iOS为APNs Device Token，Android为各厂商Push Token）
2. 将令牌与用户身份（若有）绑定，通过API发送到后端存储
3. 后端根据存储的令牌，调用对应平台的推送API下发通知

客户端代码示例 #

iOS（Swift）获取APNs令牌并同步到后端 #

import UIKit
import UserNotifications

class AppDelegate: UIResponder, UIApplicationDelegate, UNUserNotificationCenterDelegate {

    func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplication.LaunchOptionsKey: Any]?) -> Bool {
        // 请求通知权限
        UNUserNotificationCenter.current().requestAuthorization(options: [.alert, .badge, .sound]) { granted, _ in
            if granted {
                DispatchQueue.main.async {
                    application.registerForRemoteNotifications()
                }
            }
        }
        UNUserNotificationCenter.current().delegate = self
        return true
    }

    // 成功获取APNs令牌
    func application(_ application: UIApplication, didRegisterForRemoteNotificationsWithDeviceToken deviceToken: Data) {
        // 转换为字符串格式
        let tokenString = deviceToken.map { String(format: "%02.2hhx", $0) }.joined()
        // 同步到后端
        syncTokenToBackend(token: tokenString, platform: "iOS")
    }

    // 获取令牌失败处理
    func application(_ application: UIApplication, didFailToRegisterForRemoteNotificationsWithError error: Error) {
        print("APNs令牌获取失败: \(error.localizedDescription)")
    }

    // 向后端发送令牌的网络请求
    private func syncTokenToBackend(token: String, platform: String) {
        guard let url = URL(string: "https://your-api-domain.com/api/device-tokens") else { return }
        var request = URLRequest(url: url)
        request.httpMethod = "POST"
        request.setValue("application/json", forHTTPHeaderField: "Content-Type")
        
        let payload = [
            "device_token": token,
            "platform": platform,
            "user_id": "当前用户ID（如果有）"
        ]
        request.httpBody = try? JSONSerialization.data(withJSONObject: payload)
        
        URLSession.shared.dataTask(with: request) { _, response, error in
            if let error = error {
                print("令牌同步失败: \(error)")
                return
            }
            // 可根据后端响应处理成功逻辑
        }.resume()
    }
}

Android（Kotlin）获取厂商推送令牌（以华为为例）并同步到后端 #

如果不用Firebase，推荐使用Android厂商自带推送通道（华为、小米、OPPO等），以下是华为Push Token的获取示例：

import android.os.Bundle
import androidx.appcompat.app.AppCompatActivity
import com.huawei.hms.push.HmsMessaging
import okhttp3.MediaType.Companion.toMediaType
import okhttp3.OkHttpClient
import okhttp3.Request
import okhttp3.RequestBody.Companion.toRequestBody

class MainActivity : AppCompatActivity() {
    private val client = OkHttpClient()

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_main)
        
        // 获取华为Push Token
        HmsMessaging.getInstance(this).token.addOnCompleteListener { task ->
            if (task.isSuccessful) {
                task.result?.let { token ->
                    syncTokenToBackend(token, "Android-Huawei")
                }
            } else {
                print("华为Push Token获取失败: ${task.exception?.localizedDescription}")
            }
        }
    }

    // 同步令牌到后端
    private fun syncTokenToBackend(token: String, platform: String) {
        val url = "https://your-api-domain.com/api/device-tokens"
        val mediaType = "application/json; charset=utf-8".toMediaType()
        val payload = """
            {
                "device_token": "$token",
                "platform": "$platform",
                "user_id": "当前用户ID（如果有）"
            }
        """.trimIndent()
        val requestBody = payload.toRequestBody(mediaType)
        
        val request = Request.Builder()
            .url(url)
            .post(requestBody)
            .build()
        
        client.newCall(request).enqueue(object : okhttp3.Callback {
            override fun onFailure(call: okhttp3.Call, e: java.io.IOException) {
                e.printStackTrace()
            }

            override fun onResponse(call: okhttp3.Call, response: okhttp3.Response) {
                response.close()
                // 处理成功响应
            }
        })
    }
}

后端关键处理逻辑 #

1. 令牌存储：提供POST接口接收客户端发送的令牌，将其与用户ID（若有）、平台类型关联，存入数据库（注意令牌可能更新，需覆盖旧值）
2. 推送发送：
   • iOS：调用APNs HTTP/2 API，需提前在苹果开发者平台申请APNs证书或密钥，请求示例（Node.js）：

     const axios = require('axios');
     const jwt = require('jsonwebtoken');
     const fs = require('fs');
     
     // 生成APNs JWT令牌
     const generateAPNsToken = () => {
         const privateKey = fs.readFileSync('apns-private-key.p8');
         return jwt.sign({}, privateKey, {
             algorithm: 'ES256',
             issuer: '你的Team ID',
             header: { kid: '你的Key ID' }
         });
     };
     
     // 发送APNs通知
     const sendAPNsNotification = async (deviceToken, title, content) => {
         const apnsToken = generateAPNsToken();
         await axios.post(`https://api.push.apple.com/3/device/${deviceToken}`, {
             aps: {
                 alert: { title, body: content },
                 sound: 'default'
             }
         }, {
             headers: {
                 'Authorization': `bearer ${apnsToken}`,
                 'apns-topic': '你的App Bundle ID'
             }
         });
     };
     

   • Android厂商通道：调用对应厂商的推送API（如华为Push API、小米Push API），需在厂商开发者平台申请API密钥，按文档构造请求即可

注意事项 #

• 令牌可能因用户重装App、系统更新、设备重置等情况变更，客户端需在每次获取到新令牌时重新同步到后端
• 处理用户拒绝通知权限的场景，可引导用户前往设置开启
• 后端需监听推送API的错误响应（如令牌失效），及时从数据库移除无效令牌，避免无效推送请求

内容的提问来源于stack exchange，提问作者Ilian Gion Häsler