Firebase Admin NoClassDefFoundError: FirebaseOptions$Builder

Question

I'm using this:

FileInputStream serviceAccount;
    try {
        serviceAccount = new FileInputStream("firebase_key.json");
    } catch (FileNotFoundException e) {
        System.out.println(e.getMessage());
        return;
    }
    System.out.println("Reached here!");

    FirebaseOptions options = new FirebaseOptions.Builder()
            .setCredential(FirebaseCredentials.fromCertificate(serviceAccount))
            .setDatabaseUrl("https://*.firebaseio.com/")
            .build();

    FirebaseApp.initializeApp(options);

However, the application crashes with a java.lang.NoClassDefFoundError for FirebaseOptions$Builder

My build.gradle:

dependencies {
    testCompile group: 'junit', name: 'junit', version: '4.11'
    compile 'com.google.firebase:firebase-admin:4.1.1'
}

I'm using IntelliJ.

Logcat:

    Exception in thread "main" java.lang.NoClassDefFoundError: com/google/firebase/FirebaseOptions$Builder
10:57:43 AM web.1 |     at com.x.*.TokenGenerator.main(TokenGenerator.java:26)
10:57:43 AM web.1 |  Caused by: java.lang.ClassNotFoundException: com.google.firebase.FirebaseOptions$Builder
10:57:43 AM web.1 |     at java.net.URLClassLoader.findClass(Unknown Source)
10:57:43 AM web.1 |     at java.lang.ClassLoader.loadClass(Unknown Source)
10:57:43 AM web.1 |     at sun.misc.Launcher$AppClassLoader.loadClass(Unknown Source)
10:57:43 AM web.1 |     at java.lang.ClassLoader.loadClass(Unknown Source)

I have my firebase_key.json in the root of the app.

What's causing this?

Answer 1

The problem turned out to be that I was using this command to build:

gradlew clean install

However, the Jar generated by that doesn't contain the dependencies. And the Firebase Admin SDK is a dependency.

So what I did is I used shadowJar, which generates a Jar that contains dependencies. Unlike gradlew clean install.

Then, in the Procfile, I set it to the Jar that shadowJar generates. The only problem I see to have is, now I have to go to IntelliJ and run the shadowJar from there, since there doesn't seem any command to run it from the commandline.

Hope this helps