Send mail through gmail smtp using javamail

import java.security.Security;
import java.util.Properties;

import javax.mail.Authenticator;
import javax.mail.Message;
import javax.mail.PasswordAuthentication;
import javax.mail.Session;
import javax.mail.Transport;
import javax.mail.internet.InternetAddress;
import javax.mail.internet.MimeMessage;

import com.sun.net.ssl.internal.ssl.Provider;

public class GmailSend {
private String mailhost = "smtp.gmail.com";

public synchronized void sendMail(String subject, String body, String sender, String recipients) throws Exception {

Security.addProvider(new Provider());

Properties props = new Properties();
props.setProperty("mail.transport.protocol", "smtp");
props.setProperty("mail.host", "smtp.gmail.com");
props.put("mail.smtp.auth", "true");
props.put("mail.smtp.port", "465");
props.put("mail.smtp.socketFactory.port", "465");
props.put("mail.smtp.socketFactory.class", "javax.net.ssl.SSLSocketFactory");
props.put("mail.smtp.socketFactory.fallback", "false");
props.setProperty("mail.smtp.quitwait", "false");

Session session = Session.getDefaultInstance(props, new Authenticator() {
protected PasswordAuthentication getPasswordAuthentication() {
return new PasswordAuthentication("test.yu@gmail.com", "****password****");
}
});

MimeMessage message = new MimeMessage(session);
message.setSender(new InternetAddress(sender));
message.setSubject(subject);
message.setContent(body, "text/plain");
if (recipients.indexOf(',') > 0)
message.setRecipients(Message.RecipientType.TO, InternetAddress.parse(recipients));
else
message.setRecipient(Message.RecipientType.TO, new InternetAddress(recipients));

Transport.send(message);
System.out.println("finished!");
}

public static void main(String args[]) throws Exception {
GmailSend gmailSend = new GmailSend();
gmailSend.sendMail("send from javamail", "send form javamail by java programmng.", "test.yu@gmail.com",
"test.yu@gmail.com");
}

}