Summary

I follow this quickstart https://developers.google.com/gmail/api/quickstart/java
I create a project and enable the Gmail API
https://developers.google.com/workspace/guides/create-project
I create credentials
https://developers.google.com/workspace/guides/create-credentials
API Key, OAuth client ID, and a Service Account, I download the json file while I create the key in service Account, and I put this file as credentials.json in src/main/resources

Sample Name

Gmail Java Quickstart

Expected Behavior

no exception

Actual Behavior

$ gradle run

Task :run FAILED
Exception in thread "main" java.lang.IllegalArgumentException
at com.google.common.base.Preconditions.checkArgument(Preconditions.java:131)
at com.google.api.client.util.Preconditions.checkArgument(Preconditions.java:35)
at com.google.api.client.googleapis.auth.oauth2.GoogleClientSecrets.getDetails(GoogleClientSecrets.java:80)
at com.google.api.client.googleapis.auth.oauth2.GoogleAuthorizationCodeFlow$Builder.(GoogleAuthorizationCodeFlow.java:211)
at GmailQuickstart.getCredentials(GmailQuickstart.java:55)
at GmailQuickstart.main(GmailQuickstart.java:69)

Specifications

• Java version (java -version)
  $ java -version
  java version "18.0.1.1" 2022-04-22
  Java(TM) SE Runtime Environment (build 18.0.1.1+2-6)
  Java HotSpot(TM) 64-Bit Server VM (build 18.0.1.1+2-6, mixed mode, sharing)

• OS Mac