Android Build Error: Duplicate Class with Protobuf When Adding Firebase In-App Messaging

Question

I am working on an Android project that uses multiple Firebase libraries, which have been functioning without any issues. However, I recently attempted to implement Firebase In-App Messaging, and this has led to a build failure with an error indicating a "duplicate protobuf class".

Error Message:

Duplicate class com.google.protobuf.AbstractMessageLite found in modules jetified-protobuf-java-2.5.0 (com.google.protobuf:protobuf-java:2.5.0) and jetified-protobuf-javalite-3.22.3 (com.google.protobuf:protobuf-javalite:3.22.3)
Duplicate class com.google.protobuf.AbstractMessageLite$Builder found in modules jetified-protobuf-java-2.5.0 (com.google.protobuf:protobuf-java:2.5.0) and jetified-protobuf-javalite-3.22.3 (com.google.protobuf:protobuf-javalite:3.22.3)
Duplicate class com.google.protobuf.AbstractMessageLite$Builder$LimitedInputStream found in modules jetified-protobuf-java-2.5.0 (com.google.protobuf:protobuf-java:2.5.0) and jetified-protobuf-javalite-3.22.3 (com.google.protobuf:protobuf-javalite:3.22.3)
Duplicate class com.google.protobuf.AbstractParser found in modules jetified-protobuf-java-2.5.0 (com.google.protobuf:protobuf-java:2.5.0) and jetified-protobuf-javalite-3.22.3 (com.google.protobuf:protobuf-javalite:3.22.3)
Duplicate class com.google.protobuf.ByteString found in modules jetified-protobuf-java-2.5.0 (com.google.protobuf:protobuf-java:2.5.0) and jetified-protobuf-javalite-3.22.3 (com.google.protobuf:protobuf-javalite:3.22.3)
Duplicate class com.google.protobuf.ByteString$1 found in modules jetified-protobuf-java-2.5.0 (com.google.protobuf:protobuf-java:2.5.0) and jetified-protobuf-javalite-3.22.3 (com.google.protobuf:protobuf-javalite:3.22.3)
Duplicate class com.google.protobuf.ByteString$ByteIterator found in modules jetified-protobuf-java-2.5.0 (com.google.protobuf:protobuf-java:2.5.0) and jetified-protobuf-javalite-3.22.3 (com.google.protobuf:protobuf-javalite:3.22.3)
Duplicate class com.google.protobuf.ByteString$CodedBuilder found in modules jetified-protobuf-java-2.5.0 (com.google.protobuf:protobuf-java:2.5.0) and jetified-protobuf-javalite-3.22.3 (com.google.protobuf:protobuf-javalite:3.22.3)

Trying to add this dependency implementation("com.google.firebase:firebase-inappmessaging-display:21.0.0")

Attempted Solutions:

1. I tried excluding the protobuf classes in my Gradle file:

implementation("com.google.firebase:firebase-inappmessaging-display:21.0.0") {  
    exclude group: 'com.google.protobuf' 
}

2. Also tried old version for that.
3. I incorporated the Firebase Bill of Materials (BOM) to manage versions automatically:

implementation platform('com.google.firebase:firebase-bom:xx.x.x')
implementation 'com.google.firebase:firebase-inappmessaging-display'

Despite these attempts, the problem persists. My project's relevant dependencies are as follows:

dependencies {
        classpath 'com.android.tools.build:gradle:8.0.2'
        classpath 'com.google.gms:google-services:4.3.15'
        classpath "org.jetbrains.kotlin:kotlin-gradle-plugin:$kotlin_version"
        classpath 'com.google.firebase:firebase-crashlytics-gradle:2.7.1'
        classpath "androidx.navigation:navigation-safe-args-gradle-plugin:$nav_version"
        classpath 'com.jfrog.bintray.gradle:gradle-bintray-plugin:1.8.4'
        classpath 'com.google.firebase:perf-plugin:1.3.4'  // Performance Monitoring plugin
    }
dependencies {
    implementation('com.google.firebase:firebase-messaging:22.0.0') {
        exclude group: 'com.google.firebase', module: 'firebase-analytics'
        exclude group: 'com.google.firebase', module: 'firebase-measurement-connector'
    }
    implementation 'com.google.firebase:firebase-analytics:20.1.2'
    implementation 'com.google.firebase:firebase-auth:21.0.1'
    implementation 'com.google.firebase:firebase-core:20.1.2'
    implementation 'com.google.firebase:firebase-crashlytics:18.2.1'
    implementation 'com.google.firebase:firebase-iid:21.1.0'
    implementation 'com.firebase:firebase-jobdispatcher:0.8.6'
    implementation 'com.google.firebase:firebase-perf:19.0.1'
    implementation 'com.firebaseui:firebase-ui-auth:4.3.1'
    implementation 'com.google.firebase:firebase-appcheck-playintegrity:17.0.1'
}

Question: How can I resolve the duplicate class issue caused by protobuf when adding Firebase In-App Messaging to my project? Is there a specific configuration or version management technique I should follow?

Thank you in advance for your help!

Answer 1

After much debugging, I finally got a solution for that. The conflict is for

org.whispersystems:signal-protocol-java:2.6.2

This library using protobuf Java, and it is causing the duplicate class error. After updating this to the latest version, my Gradle build was successful. Also, I want to mention one more thing: you may go through app crashes because of protobuf library conflicts.

For that, you can use this solution:

configurations {
configureEach {
    resolutionStrategy {
        force group: 'com.google.protobuf', name: 'protobuf-javalite', version: '3.10.0'
    } 
}}

you can refer this link protobuf-crash