无法解析FirebaseMessagingService android

Question

我是android studio的新手，我正在尝试设置firebase消息，但我一直在消息接收器类中得到错误：

无法解析FirebaseMessagingService

我已经设置了所有的gradle依赖项，不知道我哪里出错了，这是我的代码：

Project Gradle脚本

buildscript {
    repositories {
        jcenter()
    }
    dependencies {
        classpath 'com.android.tools.build:gradle:2.3.3'
        classpath 'com.google.gms:google-services:3.1.1' // google-services plugin
        // NOTE: Do not place your application dependencies here; they belong
        // in the individual module build.gradle files
    }
}

allprojects {
    repositories {
        jcenter()
        maven {
            url "https://maven.google.com" // Google's Maven repository
        }
    }
}

task clean(type: Delete) {
    delete rootProject.buildDir
}

app gradle脚本

apply plugin: 'com.android.application'

android {
    compileSdkVersion 27
    buildToolsVersion "27.0.3"
    defaultConfig {
        applicationId "com.app.com"
        minSdkVersion 22
        targetSdkVersion 27
        versionCode 1
        versionName "1.0"
        testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner"
    }
    buildTypes {
        release {
            minifyEnabled false
            proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
        }
    }
    allprojects {
        repositories {
            jcenter()
            maven {
                url "https://maven.google.com"
            }
        }
    }
}

dependencies {
    compile fileTree(dir: 'libs', include: ['*.jar'])
    androidTestCompile('com.android.support.test.espresso:espresso-core:2.2.2', {
        exclude group: 'com.android.support', module: 'support-annotations'
    })
    compile 'com.android.support:appcompat-v7:27.+'
    compile 'com.android.support.constraint:constraint-layout:1.0.2'

    compile 'com.google.firebase:firebase-core:11.8.0'
    compile 'com.google.firebase:firebase-messaging:11.8.0'
    compile 'com.google.android.gms:play-services:11.8.0'
    testCompile 'junit:junit:4.12'
}

apply plugin: "com.google.gms.google-services"

我的课：

package com.app.com;

import FirebaseMessagingService;

/**
 * Created by abdulahmad on 1/4/18.
 */

public class PushMessageReceiver extends FirebaseMessagingService {
    private static final String TAG = "FCM Service";
    @Override
    public void onMessageReceived(RemoteMessage remoteMessage) {
        // TODO: Handle FCM messages here.
        // If the application is in the foreground handle both data and notification messages here.
        // Also if you intend on generating your own notifications as a result of a received FCM
        // message, here is where that should be initiated.
        Log.d(TAG, "From: " + remoteMessage.getFrom());
        Log.d(TAG, "Notification Message Body: " + remoteMessage.getNotification().getBody());
    }
}

Answer 1

显然你有错误的导入，它应该是From docs

import com.google.firebase.messaging.FirebaseMessagingService;

代替

import FirebaseMessagingService;