我开始研究FCM模块，但按照Firebase指南休假。我收到两个类似RuntimeException和IllegalStateException的异常。 Firebase初始默认设置，但是为什么以及FCM中的问题是什么。
我喜欢下面的链接：
https://firebase.google.com/docs/cloud-messaging/android/client
App：Build.gradle
dependencies {
implementation fileTree(dir: 'libs', include: ['*.jar'])
//noinspection GradleCompatible
implementation 'com.android.support:appcompat-v7:28.0.0'
implementation 'com.android.support.constraint:constraint-layout:1.1.3'
implementation 'com.google.firebase:firebase-messaging:17.4.0'
testImplementation 'junit:junit:4.12'
androidTestImplementation 'com.android.support.test:runner:1.0.2'
androidTestImplementation 'com.android.support.test.espresso:espresso-core:3.0.2'
}
apply plugin: 'com.google.gms.google-services'
项目：Build.gradle
buildscript {
repositories {
google()
jcenter()
}
dependencies {
classpath 'com.android.tools.build:gradle:3.3.2'
classpath 'com.google.gms:google-services:4.1.0'
// NOTE: Do not place your application dependencies here; they belong
// in the individual module build.gradle files
}
}
allprojects {
repositories {
google()
jcenter()
}
}
task clean(type: Delete) {
delete rootProject.buildDir
}
在MainActivity.class中，我尝试获取令牌，但应用程序崩溃。
public class MainActivity extends AppCompatActivity {
public static final String TAG = MainActivity.class.getSimpleName();
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
String tokenId = FirebaseInstanceId.getInstance().getToken(); //Crashes in this line
Log.d("SH", tokenId);
}
}
在logcat中，我有两个例外
E/AndroidRuntime: FATAL EXCEPTION: main
Process: com.package PID: 29368
java.lang.RuntimeException: Unable to start activity ComponentInfo{com.package.testfcm/com.package.MainActivity}: java.lang.IllegalStateException: Default FirebaseApp is not initialized in this process com.package. Make sure to call FirebaseApp.initializeApp(Context) first.
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2861)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2943)
at android.app.ActivityThread.-wrap11(Unknown Source:0)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1630)
at android.os.Handler.dispatchMessage(Handler.java:106)
at android.os.Looper.loop(Looper.java:164)
at android.app.ActivityThread.main(ActivityThread.java:6626)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:438)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:811)
Caused by: java.lang.IllegalStateException: Default FirebaseApp is not initialized in this process com.package. Make sure to call FirebaseApp.initializeApp(Context) first.
at com.google.firebase.FirebaseApp.getInstance(com.google.firebase:firebase-common@@16.0.2:240)
at com.google.firebase.iid.FirebaseInstanceId.getInstance(Unknown Source:1)
at com.package.MainActivity.onCreate(MainActivity.java:20)
at android.app.Activity.performCreate(Activity.java:7032)
at android.app.Activity.performCreate(Activity.java:7023)
at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1236)
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2814)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2943)
at android.app.ActivityThread.-wrap11(Unknown Source:0)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1630)
at android.os.Handler.dispatchMessage(Handler.java:106)
at android.os.Looper.loop(Looper.java:164)
at android.app.ActivityThread.main(ActivityThread.java:6626)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:438)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:811)
最后，我找到了解决方案，现在我可以获取FCM令牌。
请按照以下解决方案中的一个进行交叉检查项目：build.gradle文件和app：build.gradle文件。
项目：build.gradle
buildscript {
repositories {
mavenLocal() //This is the line you need to add
google()
jcenter()
}
dependencies {
classpath 'com.android.tools.build:gradle:3.3.2'
classpath 'com.google.gms:google-services:4.2.0'
// NOTE: Do not place your application dependencies here; they belong
// in the individual module build.gradle files
}
}
allprojects {
repositories {
mavenLocal() //This is the line you need to add
google()
jcenter()
}
}
task clean(type: Delete) {
delete rootProject.buildDir
}
App：build.gradle
apply plugin: 'com.android.application'
android {
compileSdkVersion 28
defaultConfig {
applicationId "com.example.testfcm"
minSdkVersion 21
targetSdkVersion 28
versionCode 1
versionName "1.0"
testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner"
}
buildTypes {
release {
minifyEnabled false
proguardFiles getDefaultProguardFile('proguard-android-optimize.txt'), 'proguard-rules.pro'
}
}
}
dependencies {
implementation fileTree(dir: 'libs', include: ['*.jar'])
//noinspection GradleCompatible
implementation 'com.android.support:appcompat-v7:28.0.0'
implementation 'com.android.support.constraint:constraint-layout:1.1.3'
implementation 'com.google.firebase:firebase-core:16.0.8'
implementation 'com.google.firebase:firebase-iid:17.1.1'
implementation 'com.google.firebase:firebase-messaging:17.5.0'
testImplementation 'junit:junit:4.12'
androidTestImplementation 'com.android.support.test:runner:1.0.2'
androidTestImplementation 'com.android.support.test.espresso:espresso-core:3.0.2'
}
apply plugin: 'com.google.gms.google-services'
答案 0 :(得分：0)
我从您的代码中看到，您必须先初始化Firebase实例。您必须先对其进行初始化，然后使用getInstance()获取令牌。
FirebaseApp.initializeApp(this);
或者尝试使用Google文档显示的方式来获取令牌
FirebaseInstanceId.getInstance().getInstanceId()
.addOnCompleteListener(new OnCompleteListener<InstanceIdResult>() {
@Override
public void onComplete(@NonNull Task<InstanceIdResult> task) {
if (!task.isSuccessful()) {
Log.w(TAG, "getInstanceId failed", task.getException());
return;
}
// Get new Instance ID token
String token = task.getResult().getToken();
Toast.makeText(MainActivity.this, token, Toast.LENGTH_SHORT).show();
}
});
答案 1 :(得分：0)
尝试这种方式。
在Android Studio中，转到“工具”菜单。
然后选择Firebase选项。
提供您启用了Firebase的Google帐户ID密码。
在右侧选项卡中，选择云消息传递。
然后单击设置Firebase消息传递。
按照那里的提到步骤。