클래스를 초기화 할 수 없습니다. Firebase에서 FirebaseThreadManagers 오류가 발생했습니다.

Question

Google App Engine에서 Firebase 데이터베이스를 조작하려고합니다. 아래에있는 내 코드와 같이

org.slf4j.LoggerFactory is a restricted class. Please see the Google App Engine developer's guide for more details. 

오류는 FirebaseOptions에서 발생

java.lang.NoClassDefFoundError: Could not initialize class com.google.firebase.internal.FirebaseThreadManagers

때때로 나는 다음을 참조 - 다음 자습서를 가지고, 나는 다음과 같은 오류를 받고 있어요. 여기

 FileInputStream serviceAccount = new FileInputStream("WEB-INF/MyApp.json"); 

    FirebaseOptions options = new FirebaseOptions.Builder() 
      .setCredentials(GoogleCredentials.fromStream(serviceAccount)) 
      .setDatabaseUrl("https://MyApp.firebaseio.com") 
      .build(); 

    FirebaseApp.initializeApp(options); 

다음은 백엔드 내 build.gradle의 전체

java.lang.NoClassDefFoundError: Could not initialize class com.google.firebase.internal.FirebaseThreadManagers at com.google.firebase.FirebaseOptions$Builder.(FirebaseOptions.java:147) at com.example.name.myapplication.backend.MyServlet.doGet(MyServlet.java:55) at javax.servlet.http.HttpServlet.service(HttpServlet.java:617) at javax.servlet.http.HttpServlet.service(HttpServlet.java:717) at org.mortbay.jetty.servlet.ServletHolder.handle(ServletHolder.java:511) at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1166) at com.google.appengine.api.blobstore.dev.ServeBlobFilter.doFilter(ServeBlobFilter.java:63) at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1157) at com.google.appengine.tools.development.DevAppServerModulesFilter.doRedirectedModuleRequest(DevAppServerModulesFilter.java:415) at com.google.appengine.tools.development.DevAppServerModulesFilter.doFilter(DevAppServerModulesFilter.java:128) at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1157) at org.mortbay.jetty.servlet.ServletHandler.handle(ServletHandler.java:388) at org.mortbay.jetty.security.SecurityHandler.handle(SecurityHandler.java:216) at org.mortbay.jetty.servlet.SessionHandler.handle(SessionHandler.java:182) at org.mortbay.jetty.handler.ContextHandler.handle(ContextHandler.java:765) at org.mortbay.jetty.webapp.WebAppContext.handle(WebAppContext.java:418) at com.google.appengine.tools.development.DevAppEngineWebAppContext.handle(DevAppEngineWebAppContext.java:98) at org.mortbay.jetty.servlet.Dispatcher.forward(Dispatcher.java:327) at org.mortbay.jetty.servlet.Dispatcher.forward(Dispatcher.java:126) at com.google.appengine.tools.development.JettyContainerService.forwardToServer(JettyContainerService.java:458) at com.google.appengine.tools.development.Modules.forwardToInstance(Modules.java:372) at com.google.appengine.tools.development.DelegatingModulesFilterHelper.forwardToInstance(DelegatingModulesFilterHelper.java:95) at com.google.appengine.tools.development.DevAppServerModulesFilter.doRedirect(DevAppServerModulesFilter.java:326) at com.google.appengine.tools.development.DevAppServerModulesFilter.doFilter(DevAppServerModulesFilter.java:119) at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1157) at org.mortbay.jetty.servlet.ServletHandler.handle(ServletHandler.java:388) at org.mortbay.jetty.security.SecurityHandler.handle(SecurityHandler.java:216) at org.mortbay.jetty.servlet.SessionHandler.handle(SessionHandler.java:182) at org.mortbay.jetty.handler.ContextHandler.handle(ContextHandler.java:765) at org.mortbay.jetty.webapp.WebAppContext.handle(WebAppContext.java:418) at com.google.appengine.tools.development.DevAppEngineWebAppContext.handle(DevAppEngineWebAppContext.java:98) at org.mortbay.jetty.handler.HandlerWrapper.handle(HandlerWrapper.java:152) at com.google.appengine.tools.development.JettyContainerService$ApiProxyHandler.handle(JettyContainerService.java:511) at org.mortbay.jetty.handler.HandlerWrapper.handle(HandlerWrapper.java:152) at org.mortbay.jetty.Server.handle(Server.java:326) at org.mortbay.jetty.HttpConnection.handleRequest(HttpConnection.java:542) at org.mortbay.jetty.HttpConnection$RequestHandler.headerComplete(HttpConnection.java:923) at org.mortbay.jetty.HttpParser.parseNext(HttpParser.java:547) at org.mortbay.jetty.HttpParser.parseAvailable(HttpParser.java:212) at org.mortbay.jetty.HttpConnection.handle(HttpConnection.java:404) at org.mortbay.io.nio.SelectChannelEndPoint.run(SelectChannelEndPoint.java:409) at org.mortbay.thread.QueuedThreadPool$PoolThread.run(QueuedThreadPool.java:582)

의 오류입니다

buildscript { 
    repositories { 
     jcenter() 
    } 
    dependencies { 
     classpath 'com.google.appengine:gradle-appengine-plugin:1.9.42' 
    } 
} 

repositories { 
    jcenter(); 
} 

apply plugin: 'java' 
apply plugin: 'war' 
apply plugin: 'appengine' 

sourceCompatibility = JavaVersion.VERSION_1_7 
targetCompatibility = JavaVersion.VERSION_1_7 

dependencies { 
    appengineSdk 'com.google.appengine:appengine-java-sdk:1.9.42' 
    compile 'javax.servlet:servlet-api:2.5' 
    compile 'com.google.firebase:firebase-admin:5.5.0' 
    compile 'com.squareup.retrofit2:retrofit:2.1.0' 
    compile 'com.squareup.retrofit2:converter-gson:2.1.0' 
    compile 'com.google.code.gson:gson:2.6.1' 


    appengine { 
     downloadSdk = true 
     appcfg { 
      oauth2 = true 
     } 
    } 
} 

최고 수준의 빌드 파일 :

buildscript { 
    repositories { 
     jcenter() 
    } 
    dependencies { 
     classpath 'com.android.tools.build:gradle:3.0.1' 


     // NOTE: Do not place your application dependencies here; they belong 
     // in the individual module build.gradle files 
     classpath 'com.google.gms:google-services:3.1.0' 
    } 
} 

allprojects { 
    repositories { 
     jcenter() 
     maven { url "https://maven.google.com" } 
    } 
} 

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

Answer 1

는 사용하지 마십시오 firebase-admin 의존성과 다른 Android cl 서버 응용 프로그램의 ient 라이브러리. firebase-admin 만 있으면 JVM 런타임에서 실시간 데이터베이스에 액세스하는 데 필요한 모든 것이 있습니다. Android 클라이언트 라이브러리는 Android 인프라가 필요하기 때문에 서버 앱에서는 사용할 수 없습니다.