Java Miscellaneous

-- Print the total time taken to perform a task

package com.java.knots;

public class TotalTime {

public static void main(String[] args) {
long programStartTime = 0;
programStartTime = System.currentTimeMillis();
/*
* perform required task
*/
long programEndTime = System.currentTimeMillis();
long minutes = ((programEndTime - programStartTime)/1000) / 60;
long seconds = ((programEndTime - programStartTime)/1000) % 60;
System.out.println("Task performed in "+minutes+" Minutes "+seconds+" Seconds");
}
}

Try for below task!

for(int i=0; i<100000000; i++)
System.out.print("");

The output in my system was "Task performed in 0 Minutes 8 Seconds"


-- How to send an Email using Java code!

import java.io.UnsupportedEncodingException;
import java.util.Properties;

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


public class SendEmail {

    public static void main(String[] args) throws InterruptedException {

        final String username = "deepak*****@gmail.com"; //supply your own userid
        final String password = "********"; //supply your own password
     
        String fromAddress = "deepak*****@gmail.com";
        String toAddresses = "deepak******@gmail.com"; //,rohitvishwakarma06@gmail.com";
     
        Properties props = new Properties();
        props.put("mail.smtp.starttls.enable", "true");
        props.put("mail.smtp.auth", "true");
        props.put("mail.smtp.host", "smtp.gmail.com");
        props.put("mail.smtp.port", "587");

        Session session = Session.getInstance(props,
          new javax.mail.Authenticator() {
            protected PasswordAuthentication getPasswordAuthentication() {
                return new PasswordAuthentication(username, password);
            }
          });

        try {

            Message message = new MimeMessage(session);
            message.setFrom(new InternetAddress(fromAddress));
            message.setRecipients(Message.RecipientType.TO,InternetAddress.parse(toAddresses));
            message.setSubject("Test#1");
            message.setText("I am glad that it is working...!");
         
            Transport.send(message);
            System.out.println("Done");

        } catch (MessagingException e) {
            throw new RuntimeException(e);
        }
    }
}

-- How to use TimerTask for cronjobs in Java

Main.java

public class Main{
   public static void main(String[] args){

     Timer t = new Timer();
     MyTask mTask = new MyTask();
     // This task is scheduled to run every 10 seconds

     t.scheduleAtFixedRate(mTask, 0, 10000);
   }

}

MyTask.java

class MyTask extends TimerTask{

   public MyTask(){
     //Some stuffs
   }

   @Override
   public void run() {
     System.out.println("Hi see you after 10 seconds");
   }

}