HQL with Aggregate functions

<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
  xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
  <modelVersion>4.0.0</modelVersion>

  <groupId>HQLAggregateFunctions</groupId>
  <artifactId>HQLAggregateFunctions</artifactId>
  <version>0.0.1-SNAPSHOT</version>
  <packaging>jar</packaging>

  <name>HQLAggregateFunctions</name>
  <url>http://maven.apache.org</url>

  <properties>
    <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
  </properties>

  <dependencies>

    <dependency>
      <groupId>junit</groupId>
      <artifactId>junit</artifactId>
      <version>3.8.1</version>
      <scope>test</scope>
    </dependency>

     <!-- https://mvnrepository.com/artifact/org.hibernate/hibernate-core -->
		<dependency>
			<groupId>org.hibernate</groupId>
			<artifactId>hibernate-core</artifactId>
			<version>5.2.6.Final</version>
		</dependency>

		<!-- https://mvnrepository.com/artifact/mysql/mysql-connector-java -->
		<dependency>
			<groupId>mysql</groupId>
			<artifactId>mysql-connector-java</artifactId>
			<version>6.0.5</version>
		</dependency>

  </dependencies>
</project>

package com.kb.model;

import javax.persistence.Column;
import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.GenerationType;
import javax.persistence.Id;
import javax.persistence.Table;

@Entity
@Table(name="Employee")
public class Employee {

	@Id
	@GeneratedValue(strategy = GenerationType.SEQUENCE)
	@Column(name = "Employee_Id")
	private int employeeId;
	
	@Column(name = "FirstName")
	private String firstName;
	
	@Column(name = "LastName")
	private String lastName;
	
	@Column(name = "Age")
	private int age;
	
	@Column(name = "Education")
	private String education;
	
	@Column(name = "Salary")
	private int salary;
	
	public int getEmployeeId() {
		return employeeId;
	}
	public void setEmployeeId(int employeeId) {
		this.employeeId = employeeId;
	}
	public String getFirstName() {
		return firstName;
	}
	public void setFirstName(String firstName) {
		this.firstName = firstName;
	}
	public String getLastName() {
		return lastName;
	}
	public void setLastName(String lastName) {
		this.lastName = lastName;
	}
	public int getAge() {
		return age;
	}
	public void setAge(int age) {
		this.age = age;
	}
	public String getEducation() {
		return education;
	}
	public void setEducation(String education) {
		this.education = education;
	}
	public int getSalary() {
		return salary;
	}
	public void setSalary(int salary) {
		this.salary = salary;
	}
}

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE hibernate-configuration PUBLIC
       "-//Hibernate/Hibernate Configuration DTD 3.0//EN"
       "http://www.hibernate.org/dtd/hibernate-configuration-3.0.dtd">
 
<hibernate-configuration>
 
   <session-factory>
 
       <!-- Database connection properties -->
       <property name="connection.driver_class">com.mysql.jdbc.Driver</property>
       <property name="connection.url">jdbc:mysql://localhost/javainsimpleway</property>
       <property name="connection.username">root</property>
       <property name="connection.password">root</property>
 
       <!-- JDBC connection pool (using the built-in) -->
       <property name="connection.pool_size">100</property>
 
       <!-- SQL dialect -->
       <property name="dialect">org.hibernate.dialect.MySQLDialect</property>
 
       <!-- Disable the second-level cache -->
       <property name="cache.provider_class">org.hibernate.cache.internal.NoCacheProvider</property>
 
       <!-- Echo all executed SQL to stdout -->
       <property name="show_sql">true</property>
       
       <!-- Format the generated Sql -->
       <property name="format_sql">true</property>
 
       <!-- Dont Drop and re-create the database schema on startup,Just update it -->
       <property name="hbm2ddl.auto">update</property>
 
          <mapping class="com.kb.model.Employee" />
 
   </session-factory>
 
</hibernate-configuration>

package com.kb.util;

import org.hibernate.SessionFactory;
import org.hibernate.cfg.Configuration;

public class HibernateUtil {
	private static final SessionFactory sessionFactory = buildSessionFactory();

    private static SessionFactory buildSessionFactory() {
        try {
            // Create the SessionFactory from hibernate.cfg.xml
            return new Configuration().configure().buildSessionFactory();
        } catch (Throwable ex) {
            // Make sure you log the exception to track it
            System.err.println("SessionFactory creation failed." + ex);
            throw new ExceptionInInitializerError(ex);
        }
    }

    public static SessionFactory getSessionFactory() {
        return sessionFactory;
    }
    
    public static void shutdown() {
    	// Optional but can be used to Close caches and connection pools
    	getSessionFactory().close();
    }

}

package com.kb.db;

import org.hibernate.Session;
import org.hibernate.SessionFactory;
import org.hibernate.Transaction;

import com.kb.model.Employee;
import com.kb.util.HibernateUtil;

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

	// Get session factory using Hibernate Util class
	SessionFactory sf = HibernateUtil.getSessionFactory();
	// Get session from Sesson factory
	Session session = sf.openSession();

	// Begin transaction
	Transaction t = session.beginTransaction();
	
	//Create Employee  data
	Employee employee1 = new Employee();
	employee1.setFirstName("John");
	employee1.setLastName("KC");
	employee1.setAge(28);
	employee1.setEducation("PG");
	employee1.setSalary(25000);
	
	Employee employee2 = new Employee();
	employee2.setFirstName("Jacob");
	employee2.setLastName("JC");
	employee2.setAge(30);
	employee2.setEducation("PG");
	employee2.setSalary(30000);
	
	Employee employee3 = new Employee();
	employee3.setFirstName("Martin");
	employee3.setLastName("A");
	employee3.setAge(24);
	employee3.setEducation("UG");
	employee3.setSalary(20000);
	
	Employee employee4 = new Employee();
	employee4.setFirstName("Peter");
	employee4.setLastName("M");
	employee4.setAge(25);
	employee4.setEducation("UG");
	employee4.setSalary(22000);
	
	Employee employee5 = new Employee();
	employee5.setFirstName("Roshan");
	employee5.setLastName("B");
	employee5.setAge(29);
	employee5.setEducation("PG");
	employee5.setSalary(45000);
	
	
	session.save(employee1);
	session.save(employee2);
	session.save(employee3);
	session.save(employee4);
	session.save(employee5);

	// Commit the transaction and close the session
	t.commit();
	
	session.close();
	System.out.println("successfully persisted Employee details");

   }

}

package com.kb.db;

import org.hibernate.Session;
import org.hibernate.SessionFactory;
import org.hibernate.query.Query;

import com.kb.util.HibernateUtil;

public class AggregateFunctions {
	public static void main(String[] args) {
		// Get session factory using Hibernate Util class
		SessionFactory sf = HibernateUtil.getSessionFactory();
		// Get session from Sesson factory
		Session session = sf.openSession();

		// Retrieve Max salary of Employee
		Query maxSalaryQuery = session.createQuery("SELECT MAX(salary) FROM Employee");
		Object maxSalary = maxSalaryQuery.getSingleResult();
		System.out.println("Maximum salary of Employee -> " + maxSalary);

		// Retrieve Min salary of Employee
		Query minSalaryQuery = session.createQuery("SELECT MIN(salary) FROM Employee");
		Object minSalary = minSalaryQuery.getSingleResult();
		System.out.println("Minimum salary of Employee -> " + minSalary);

		// Retrieve Average salary of Employee
		Query avgSalaryQuery = session.createQuery("SELECT AVG(salary) FROM Employee");
		Object avgSalary = avgSalaryQuery.getSingleResult();
		System.out.println("Average salary of Employees -> " + avgSalary);

		// Retrieve Number of Employees
		Query empCountQuery = session.createQuery("SELECT COUNT(*) FROM Employee");
		Object empCount = empCountQuery.getSingleResult();
		System.out.println("Total number of Employees -> " + empCount);

		// Retrieve Total Sum of salary of all Employees
		Query sumSalaryQuery = session.createQuery("SELECT SUM(salary) FROM Employee");
		Object sumSalary = sumSalaryQuery.getSingleResult();
		System.out.println("Total sum of salary of all Employees -> " + sumSalary);

		session.close();
	}

}