Log4j example in java

1. Download “log4j-x.x.x.jar” file.
2. Create a java project in eclipse.
3. Open project’s properties and click on “Java Build Path” and then go to “Libraries” tab and add this jar by click on “Add External Jars..” tab.
   

Comparator interface to sort java object based on it's parameter.

Sort list of Employee object based on it's name parameter.

1.Bean class:

package com.collection.javacodepractices;

public class Employee {

      private int rollNo;

      private String name;

      public int getRollNo() {

            return rollNo;

      }

      public void setRollNo(int rollNo) {

            this.rollNo = rollNo;

      }

      public String getName() {

            return name;

      }

      public void setName(String name) {

            this.name = name;

      }

      @Override

      public String toString() {

            return "Employee [rollNo=" + rollNo + ", name=" + name + "]";

      }

}

2.Comparable class:

package com.collection.javacodepractices;

import java.util.Comparator;

public class EmployeeComparable implements Comparator<Employee>{

      @Override

      public int compare(Employee empOne, Employee empTwo) {

            return (empOne.getName().compareToIgnoreCase(empTwo.getName())<0?-1:                                                   (empOne.getName().equalsIgnoreCase(empTwo.getName())?0:1));

      }

}

3.Client class:

package com.collection.javacodepractices;

import java.util.ArrayList;

import java.util.Collections;

import java.util.List;

public class Client {

      public static void main(String args[]) {

            List<Employee> empList = new ArrayList<Employee>();

            // 1. employee setting.

            Employee emp1 = new Employee();

            emp1.setRollNo(1);

            emp1.setName("Bijoy");

            // 2. employee setting.

            Employee emp2 = new Employee();

            emp2.setRollNo(2);

            emp2.setName("Bappa");

            // 3. employee setting.

            Employee emp3 = new Employee();

            emp3.setRollNo(3);

            emp3.setName("Chintu");

            // 4. employee setting.

            Employee emp4 = new Employee();

            emp4.setRollNo(4);

            emp4.setName("Rahul");

            // 5. employee setting.

            Employee emp5 = new Employee();

            emp5.setRollNo(5);

            emp5.setName("Ajoy");

           

            //Add employee object to list.

            empList.add(emp1);

            empList.add(emp2);

            empList.add(emp3);

            empList.add(emp4);

            empList.add(emp5);

           

            //sorting employee based on name using comparator interface.

            Collections.sort(empList, new EmployeeComparable());

           

            //Print Employee object.

            for(Employee emp:empList){

                  System.out.println(emp.toString());

            }

      }

}

OUTPUT:

Employee [rollNo=5, name=Ajoy]

Employee [rollNo=2, name=Bappa]

Employee [rollNo=1, name=Bijoy]

Employee [rollNo=3, name=Chintu]

Employee [rollNo=4, name=Rahul]

Send mail using java (Exchange Server)

External jar needs to be added is "mail.jar".
========================================================
package com.myExample.mail;

public class Client {

      public static void main(String[] args) {

            String To = "abc1@xyz.com; abc2@xyz.com ; abc3@xyz.com ";

            String CC = " abc4@xyz.com; abc5@xyz.com ; abc6@xyz.com ";

            String BCC = "abc@xyz.com";

            String From = "myExmp@ddd.com";

            String Subject = "Test subject line.";

            String Body = "Test mail Body.";

            MailExample obj = new MailExample();

            obj.sendAMail(To, CC, BCC, From, Body, Subject);

      }

}

=========================================================

package com.myExample.mail;

import java.util.ArrayList;

import java.util.Arrays;

import java.util.Iterator;

import java.util.List;

import java.util.Properties;

import java.util.logging.Level;

import java.util.logging.Logger;

import javax.mail.Message;

import javax.mail.MessagingException;

import javax.mail.PasswordAuthentication;

import javax.mail.Session;

import javax.mail.Transport;

import javax.mail.internet.InternetAddress;

import javax.mail.internet.MimeMessage;

import javax.mail.internet.MimeMessage.RecipientType;

public class MailExample {

                public void sendAMail(String To, String CC, String BCC, String From,

                                                String Body, String Subject) {

                                try {

                                                Sendmail(To, CC, BCC, From, Body, Subject);

                                } catch (MessagingException ex) {

                                                Logger.getLogger(MailExample.class.getName()).log(Level.SEVERE,

                                                                                null, ex);

                                }

                }

                public void Sendmail(String To, String CC, String BCC, String From,

                                                String Body, String Subject) throws MessagingException {

                                Message message = new MimeMessage(getSession());

                                if (To != null && To.trim().length() > 0) {

                                                //Separate "To" mail address based on ";" separator and set it into mail "To" address.

                                                Iterator<String> ToIterator=this.getAddressList(To).iterator();

                                                while(ToIterator.hasNext()){

                                                                message.addRecipient(RecipientType.TO, new InternetAddress(ToIterator.next()));

                                                }

                                               

                                                if (CC != null && CC.trim().length() > 0){

                                                                //Separate "CC" mail address based on ";" separator and set it into mail "CC" address.

                                                                Iterator<String> CCIterator=this.getAddressList(CC).iterator();

                                                                while(CCIterator.hasNext()){

                                                                                message.addRecipient(RecipientType.CC, new InternetAddress(CCIterator.next()));

                                                                }

                                                }

                                                               

                                                if (BCC != null && BCC.trim().length() > 0){

                                                                //Separate "BCC" mail address based on ";" separator and set it into mail "BCC" address.

                                                                Iterator<String> BCCIterator=this.getAddressList(BCC).iterator();

                                                                while(BCCIterator.hasNext()){

                                                                                message.addRecipient(RecipientType.BCC, new InternetAddress(BCCIterator.next()));

                                                                }

                                                }

                                               

                                                if (From != null && From.trim().length() > 0)

                                                                message.addFrom(new InternetAddress[] { new InternetAddress(

                                                                                                From) });

                                                message.setSubject(Subject);

                                                message.setContent(Body, "text/plain");

                                }

                                System.out.println("Sending mail .............................");

                                Transport.send(message);

                                System.out.println("Mail sent .............................");

                }

                private Session getSession() {

                                Authenticator authenticator = new Authenticator();

                                Properties properties = new Properties();

                                properties.setProperty("mail.smtp.submitter", authenticator

                                                                .getPasswordAuthentication().getUserName());

                                properties.setProperty("mail.smtp.auth", "true");

                                properties.setProperty("mail.smtp.host", "172.16.16.99");

                                properties.setProperty("mail.smtp.port", "25");

                                return Session.getInstance(properties, authenticator);

                }

                private class Authenticator extends javax.mail.Authenticator {

                                private PasswordAuthentication authentication;

                                public Authenticator() {

                                                String username = "username";

                                                String password = password";

                                                authentication = new PasswordAuthentication(username, password);

                                }

                                protected PasswordAuthentication getPasswordAuthentication() {

                                                return authentication;

                                }

                }

               

                //Separate string using ';' separator.

                private List<String> getAddressList(String address){

                                String mailAddress=address;

                                List<String> mailAddressList = null;

                                if(mailAddress != null && mailAddress.trim().length()>0){

                                                mailAddressList = new ArrayList<String>();

                                                if(mailAddress.contains(";")){

                                                                mailAddressList=Arrays.asList(mailAddress.split(";"));

                                                }else{

                                                                mailAddressList.add(mailAddress.trim());

                                                }

                                }

                                return mailAddressList;

                }

}