I have piece of code below in which 5 different threads are created and then correspondingly run method is being called , please advise how can i add synchronization in this as i want when one thread is calling run method then no other thread should enter inside run method

```
public class SSendEmail implements Runnable {

   public static void main(String [] args) throws Exception, IOException, Exception{

      for(int i=0;i<5;i++) {
          new Thread(new SSendMail()).start();
      }
   }

   public void run() {

    String smtpHost = "xxx";
    String mailSmtpPort = "000";
    String mailTo[] = {"sart@wer.com" };
    String mailCc[] = {"sart@wer.com" };

    xxsendmail(mailTo, mailCc, "sendername",
            "testsubject.", "testsubject..", smtpHost , mailSmtpPort);
  }  
}

```