Simple OAuth 2.0 Framework for Authentication (Freeware)

import ch.k43.tools.SOFA;

public class SOFATest {

   public static void main(String[] args) {

      // Create SOFA object
      SOFA sofa = new SOFA(
         "https://login.microsoftonline.com/xxxxxxxx-xxxx-xxxx-xxxxxxxxxxxx/oauth2/v2.0/token",   // Authorization Server with Azure Tenant ID
         "https://outlook.office365.com/.default");                       // Authentication Scope

      // Authenticate with client credentials
      if (!sofa.authenticateWithClientCredentials(
         "aaaaaaaa-aaaa-aaaa-aaaa-aaaaaaaaaaaa",                              // Client ID (Application ID)
         "xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx")) {                       // Client secret (Value)
         System.out.println("Authentication failed <" + sofa.getErrorMessage() + ">");
         return;
      };

      // Show the ready-to-use HTTP request header
      System.out.println("HTTP Header <" + sofa.getHttpAuthorizationHeader() + ">");
   }
}