class file for com.google.protobuf.MessageOrBuilder not found

Question

I was working on my final year project, an android app which involves both firebase and dialogflow. I have this problem of "class file for com.google.protobuf.MessageOrBuilder not found".

This is my app gradle code:

android{
..
..
    configurations.all {
        exclude group:'com.google.api.grpc',module:'proto-google-common-protos'
        exclude group: 'com.google.protobuf'
        //exclude group: 'com.google.guava',module: 'guava-jdk5'
    }
    packagingOptions {
        exclude 'META-INF/INDEX.LIST'
        exclude 'META-INF/DEPENDENCIES'
    }
    lintOptions {
        checkReleaseBuilds false
    }
}

dependencies{
..
..
    //dialogflow
    implementation 'com.google.cloud:google-cloud-dialogflow:2.1.0'
    implementation 'io.grpc:grpc-okhttp:1.30.0'
}

These are the errors that I faced:

error: cannot access MessageOrBuilder
                .setText(TextInput.newBuilder().setText(message).setLanguageCode("en-US")).build();
                                  ^
  class file for com.google.protobuf.MessageOrBuilder not found

error: cannot access GeneratedMessageV3
        QueryInput input = QueryInput.newBuilder()
                                     ^
  class file for com.google.protobuf.GeneratedMessageV3 not found

error: cannot access Builder
                .setText(TextInput.newBuilder().setText(message).setLanguageCode("en-US")).build();
                                               ^
  class file for com.google.protobuf.GeneratedMessageV3$Builder not found

*Update: The dialogflow dependencies clashes with firebase dependencies, which causes an error for my app to connect to its firebase.

I hope u can help me. Thank you.

Answer 1

I am just starting to work with gRPC, but i may have had the same issue and in my case it worked by simply adding in gradle the below dependency:

implementation "io.grpc:grpc-protobuf:${grpcVersion}"

Simply put, my code did not have the required dependency that provided MessageOrBuilder, which is needed to deserialize the message.

I guess author found the issue (since 11 months passed). However if someone else has the same issue I propose to run a dependency tree on gradle or maven and check if the (sub-module?) has the protobuf-java dependency (which has the MessageOrBuilder class). I hope i helped.