无法使用 dialogflow 完成构建 gradle

Question

I'd like to use the latest version of dialog-flow in my Android app. However when I integrate it in my app gradle, I get the following build error:

Execution failed for task ':app:mergeDebugJavaResource'. A failure occurred while executing com.android.build.gradle.internal.tasks.Workers$ActionFacade More than one file was found with OS independent path 'META-INF/INDEX.LIST'

In order to narrow down the bug, I minimized my build gradle dependencies in a test project to:

dependencies {
    implementation fileTree(dir: 'libs', include: ['*.jar'])
    implementation 'androidx.appcompat:appcompat:1.1.0'
    implementation 'androidx.constraintlayout:constraintlayout:1.1.3'
    testImplementation 'junit:junit:4.12'
    androidTestImplementation 'androidx.test.ext:junit:1.1.1'
    androidTestImplementation 'androidx.test.espresso:espresso-core:3.2.0'
    implementation 'com.google.cloud:google-cloud-dialogflow:1.0.0'
}

I still get the same error, but at least I know that the bug is not caused by any other dependencies I have in my actual project. After searching through related forum questions, I tried many solution proposals like adding packagingOptions to my build gradle:

packagingOptions {
        exclude 'META-INF/DEPENDENCIES'
        exclude 'META-INF/LICENSE'
        exclude 'META-INF/LICENSE.txt'
        exclude 'META-INF/license.txt'
        exclude 'META-INF/NOTICE'
        exclude 'META-INF/NOTICE.txt'
        exclude 'META-INF/notice.txt'
        exclude 'META-INF/ASL2.0'
    }

and to exclude groups from my dialogflow implementation:

implementation('com.google.cloud:google-cloud-dialogflow:1.0.0'){
        exclude group: 'com.google.api.grpc'
}

The last solution proposal actually helps me to build my gradle, however as the dialogflow lib is based on grpc, most of the classes are not available anymore, which turns the whole lib quite useless for me.

I've also tried to use older versions like 0.120.2, resulting only in the same issue.

Has someone of you solved this issue already? I'm also open to use a different library to communicate with my dialogflow agent. For me it is just important to use the latest API v2 to access dialogflow (I have already some working projects with v1), as v1 will be deprecated very soon.

Thanks a lot in advance for your help!

Answer 1

In the end I found a workaround, so I don't have to use the dialogflow client library. For the authentication I use

implementation 'com.google.apis:google-api-services-oauth2:v2-rev99-1.21.0'

so I can create my credentials:

GoogleCredential credential = GoogleCredential.fromStream(new FileInputStream(file)).createScoped(Lists.newArrayList("https://www.googleapis.com/auth/cloud-platform", "https://www.googleapis.com/auth/dialogflow"));

File file is the JSON file/key that I retrieved from my Google ServiceAccount, which is assigned to my dialogflow agent. With the credential I can retrieve my access token:

private String getToken(){
    try {
        credential.refreshToken();
        return credential.getAccessToken();
    }
    catch (IOException e) {
        e.printStackTrace();
    }
    return null;
}

With the help of this token I can establish a HTTPURLConnection and send requests to my dialogflow agent:

URL url = new URL(path);
HttpURLConnection connection = (HttpURLConnection) url.openConnection();
connection.setRequestMethod("GET");
String token = getToken();
connection.setRequestProperty("Authorization", "Bearer " + token);
connection.setRequestProperty("Accept", "application/json");
connection.connect()
...

I hope, this will help other Android developers, who want to use the dialogflow v2 API!

Cheers