FCM通知在App后台/关闭时无法打开指定页面求助

需求：用户点击通知时，在WebView中打开指定链接。
正常场景：App处于前台时，用户点击通知可正常跳转到目标URL。
异常场景：App未启动或处于后台时，点击通知仅打开App，无法跳转到指定URL。

已查阅相关资料但未找到解决方案。

FirebaseMessagingService代码 #

public class FcmMessagingService extends FirebaseMessagingService {
    @Override
    public void onMessageReceived(RemoteMessage remoteMessage) {
        // Also if you intend on generating your own notifications as a result of a received FCM
        // message, here is where that should be initiated. See sendNotification method below.
        String title = remoteMessage.getNotification().getTitle();
        final String message = remoteMessage.getNotification().getBody();
        String click_action = remoteMessage.getData().get("click_action");

        sendOnChannel1(title, message, click_action);
    }

    private void sendOnChannel1(String title, String messageBody, String click_action) {
        Intent activityIntent = new Intent(this, MainActivity.class);
        activityIntent.putExtra("linkz", click_action);
        PendingIntent contentIntent = PendingIntent.getActivity(this, 1 /* Request code */, activityIntent, 0);

        String channelId = "fcm_default_channel";
        Uri defaultSoundUri = RingtoneManager.getDefaultUri(RingtoneManager.TYPE_NOTIFICATION);
        NotificationCompat.Builder notificationBuilder = new NotificationCompat.Builder(this, channelId)
                .setSmallIcon(R.mipmap.ic_icon)
                .setContentTitle(title)
                .setContentText(messageBody)
                .setPriority(NotificationCompat.PRIORITY_HIGH)
                .setCategory(NotificationCompat.CATEGORY_REMINDER)
                //.setColor(Color.BLUE)
                .setSound(defaultSoundUri)
                .setContentIntent(contentIntent)
                .setAutoCancel(true)
                .setOnlyAlertOnce(true);
                //.addAction(R.mipmap.ic_launcher, "Toast", actionIntent);

        NotificationManager notificationManager = (NotificationManager) getSystemService(Context.NOTIFICATION_SERVICE);

        // Since android Oreo notification channel is needed.
        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) {
            NotificationChannel channel = new NotificationChannel(channelId,
                    "Channel human readable title",
                    NotificationManager.IMPORTANCE_DEFAULT);
            notificationManager.createNotificationChannel(channel);
        }

        notificationManager.notify(1 /* ID of notification */, notificationBuilder.build());
    }
}

Manifest配置 #

<uses-permission android:name="android.permission.INTERNET" />
<uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />
<uses-permission android:name="android.permission.ACCESS_WIFI_STATE" />
<uses-permission android:name="android.permission.CAMERA"/>
<uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE"/>
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"/>

<meta-data android:name="android.webkit.WebView.EnableSafeBrowsing"
    android:value="true" />

<application
    android:allowBackup="true"
    android:icon="@mipmap/ic_icon"
    android:label="@string/app_name"
    android:roundIcon="@mipmap/ic_icon"
    android:supportsRtl="true"
    android:theme="@style/AppTheme"
    android:hardwareAccelerated="true"
    android:usesCleartextTraffic="true">
    <activity
        android:name=".MainActivity"
        android:parentActivityName=".welcome"
        android:screenOrientation="portrait"
        android:configChanges="orientation|screenSize"
        android:exported="true">
        <intent-filter>
            <category android:name="android.intent.category.LAUNCHER" />
        </intent-filter>
    </activity>
        <activity
            android:name=".welcome"
            android:screenOrientation="portrait"
            android:configChanges="orientation|screenSize"
            android:exported="true">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
            <intent-filter>
                <action android:name="android.intent.action.VIEW" />

                <category android:name="android.intent.category.DEFAULT" />
                <category android:name="android.intent.category.BROWSABLE" />

                <data
                    android:scheme="http"
                    android:host="www.careturtle.com"
                    />

            </intent-filter>
        </activity>
     <service android:name=".FcmMessagingService"
        android:exported="false"
        android:directBootAware="true">
        <intent-filter>
            <action android:name="com.google.firebase.MESSAGING_EVENT" />
            <category android:name="android.intent.category.DEFAULT" />
        </intent-filter>
    </service>

    <meta-data
        android:name="com.google.firebase.messaging.default_notification_icon"
        android:resource="@mipmap/ic_icon" />
    <activity
        android:name=".noconnection"
        android:screenOrientation="portrait">
    </activity>
</application>

解决方案 #

1. 修正PendingIntent标记 #

App在后台或未启动时，PendingIntent需要确保额外数据能正确传递，修改sendOnChannel1方法中的PendingIntent创建逻辑：

// 根据Android版本选择兼容标记
int flags;
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {
    flags = PendingIntent.FLAG_UPDATE_CURRENT | PendingIntent.FLAG_IMMUTABLE;
} else {
    flags = PendingIntent.FLAG_UPDATE_CURRENT;
}
PendingIntent contentIntent = PendingIntent.getActivity(this, 1, activityIntent, flags);

2. 处理MainActivity的启动Intent #

App未启动时，通知的跳转数据通过启动Intent传递，需要在MainActivity的两个生命周期方法中处理：

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

@Override
protected void onNewIntent(Intent intent) {
    super.onNewIntent(intent);
    handleNotificationIntent(intent);
}

private void handleNotificationIntent(Intent intent) {
    if (intent != null && intent.hasExtra("linkz")) {
        String targetUrl = intent.getStringExtra("linkz");
        // 跳转到WebView页面加载目标链接
        Intent webIntent = new Intent(this, WebViewActivity.class);
        webIntent.putExtra("url", targetUrl);
        startActivity(webIntent);
    }
}

3. 清理Manifest的Launcher配置 #

当前两个Activity都设置了LAUNCHER类别，会导致启动入口混乱，保留一个Launcher Activity即可：

<activity
    android:name=".MainActivity"
    android:parentActivityName=".welcome"
    android:screenOrientation="portrait"
    android:configChanges="orientation|screenSize"
    android:exported="true">
    <!-- 移除该Launcher intent-filter -->
</activity>

4. 确保FCM消息数据格式正确 #

发送FCM消息时，click_action必须放在data字段中（而非notification字段），后端请求体示例：

{
  "to": "设备令牌",
  "data": {
    "click_action": "目标URL",
    "title": "通知标题",
    "body": "通知内容"
  }
}

5. 完善WebView页面加载逻辑 #

在WebView页面中确保能正确接收并加载传递的URL：

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_webview);
    WebView webView = findViewById(R.id.webView);
    if (getIntent() != null && getIntent().hasExtra("url")) {
        String url = getIntent().getStringExtra("url");
        webView.loadUrl(url);
    }
}

内容的提问来源于stack exchange，提问作者Observer