Java

GMail SMTP Send using Previously Obtained OAuth2 Access Token

See more GMail SMTP/IMAP/POP Examples

Demonstrates how to send email using GMail and OAuth2 authentication. This example assumes an OAuth2 access token was previously obtained. Java

import com.chilkatsoft.*;

public class ChilkatExample {

  static {
    try {
        System.loadLibrary("chilkat");
    } catch (UnsatisfiedLinkError e) {
      System.err.println("Native code library failed to load.\n" + e);
      System.exit(1);
    }
  }

  public static void main(String argv[])
  {
    boolean success = false;

    //  This example requires the Chilkat API to have been previously unlocked.
    //  See Global Unlock Sample for sample code.

    //  See Get GMail SMTP Access Token 
    //  for sample code showing how to obtain a GMail SMTP access token for desktop apps.

    //  In this example, our access token was previously saved to the following file which contains JSON like this:
    //  	{
    //  	 "access_token": "ya39.Ci-XA_C5bGgRDC3UaD-h0_NeL-DVIQnI2gHtBBBHkZzrwlARkwX6R3O0PCDEzRlfaQ",
    //  	 "token_type": "Bearer",
    //  	 "expires_in": 3600,
    //  	 "refresh_token": "1/r_2c_7jddspcdfesrrfKqfXtqo08D6Q-gUU0DsdfVMsx0c"
    //  	}
    //  
    CkJsonObject json = new CkJsonObject();
    success = json.LoadFile("qa_data/tokens/_gmailSmtp.json");
    if (success != true) {
        System.out.println("Failed to load GMail access token file.");
        return;
        }

    String accessToken = json.stringOf("access_token");

    CkMailMan mailman = new CkMailMan();

    //  Set the properties for the GMail SMTP server:
    mailman.put_SmtpHost("smtp.gmail.com");
    mailman.put_SmtpPort(587);
    mailman.put_StartTLS(true);

    //  The SMTP username should be the GMail address of the user's account that authorized your app to send email.
    mailman.put_SmtpUsername("chilkat.support@gmail.com");
    mailman.put_OAuth2AccessToken(accessToken);

    //  Create a new email object
    CkEmail email = new CkEmail();

    email.put_Subject("This is a test");
    email.put_Body("This is a test");
    email.put_From("Chilkat <chilkat.support@gmail.com>");
    email.AddTo("Chilkat Admin","admin@chilkatsoft.com");
    //  To add more recipients, call AddTo, AddCC, or AddBcc once per recipient.

    //  Call SendEmail to connect to the SMTP server and send.
    //  The connection (i.e. session) to the SMTP server remains
    //  open so that subsequent SendEmail calls may use the
    //  same connection.  
    success = mailman.SendEmail(email);
    if (success != true) {
        System.out.println(mailman.lastErrorText());
        return;
        }

    //  You may close the connection here.  If the connection is kept open, 
    //  the next call to mailman.SendEmail will continue using the already-established connection
    //  (and automatically re-connect if needed).
    success = mailman.CloseSmtpConnection();
    if (success != true) {
        System.out.println("Connection to SMTP server not closed cleanly.");
        }

    System.out.println("Email Sent via GMail with OAuth2 authentication.");
  }
}