c14_hibernate.ManageEmployee.java Source code

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Here is the source code for c14_hibernate.ManageEmployee.java

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/*
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package c14_hibernate;

/**
 *
 * @author dvd
 */
import java.util.*;
import org.hibernate.Criteria;
import org.hibernate.HibernateException;
import org.hibernate.Session;
import org.hibernate.Transaction;
import org.hibernate.SessionFactory;
import org.hibernate.cfg.Configuration;
import org.hibernate.criterion.Projections;

public class ManageEmployee {
    private static SessionFactory factory;

    public static void main(String[] args) {
        try {
            factory = new Configuration().configure().buildSessionFactory();
        } catch (Throwable ex) {
            System.err.println("Failed to create sessionFactory object." + ex);
            throw new ExceptionInInitializerError(ex);
        }
        ManageEmployee ME = new ManageEmployee();
        /* Add few employee records in database */
        Integer empID1 = ME.addEmployee("Zara", "Ali", 2000);
        Integer empID2 = ME.addEmployee("Daisy", "Das", 5000);
        Integer empID3 = ME.addEmployee("John", "Paul", 5000);
        Integer empID4 = ME.addEmployee("Mohd", "Yasee", 3000);
        /* List down all the employees */
        ME.listEmployees();
        /* Print Total employee's count */
        ME.countEmployee();
        /* Print Toatl salary */
        ME.totalSalary();
        factory.close();
    }

    /* Method to CREATE an employee in the database */
    public Integer addEmployee(String fname, String lname, int salary) {
        Session session = factory.openSession();
        Transaction tx = null;
        Integer employeeID = null;
        try {
            tx = session.beginTransaction();
            Employee employee = new Employee(fname, lname, salary);
            employeeID = (Integer) session.save(employee);
            tx.commit();
        } catch (HibernateException e) {
            if (tx != null)
                tx.rollback();
            e.printStackTrace();
        } finally {
            session.close();
        }
        return employeeID;
    }

    /* Method to print total number of records */
    public void countEmployee() {
        Session session = factory.openSession();
        Transaction tx = null;
        try {
            tx = session.beginTransaction();
            Criteria cr = session.createCriteria(Employee.class);
            // To get total row count. cr.setProjection(Projections.rowCount());
            List rowCount = cr.list();
            System.out.println("Total Coint: " + rowCount.get(0));
            tx.commit();
        } catch (HibernateException e) {
            if (tx != null)
                tx.rollback();
            e.printStackTrace();
        } finally {
            session.close();
        }
    }

    /* Method to print sum of salaries */
    public void totalSalary() {
        Session session = factory.openSession();
        Transaction tx = null;
        try {
            tx = session.beginTransaction();
            Criteria cr = session.createCriteria(Employee.class);
            // To get total salary.
            cr.setProjection(Projections.sum("salary"));
            List totalSalary = cr.list();
            System.out.println("Total Salary: " + totalSalary.get(0));
            tx.commit();
        } catch (HibernateException e) {
            if (tx != null)
                tx.rollback();
            e.printStackTrace();
        } finally {
            session.close();
        }
    }

    /* Method to READ all the employees */
    public void listEmployees() {
        Session session = factory.openSession();
        Transaction tx = null;
        try {
            tx = session.beginTransaction();
            List employees = session.createQuery("FROM Employee").list();
            for (Iterator iterator = employees.iterator(); iterator.hasNext();) {
                Employee employee = (Employee) iterator.next();
                System.out.print("First Name: " + employee.getFirstName());
                System.out.print(" Last Name: " + employee.getLastName());
                System.out.println(" Salary: " + employee.getSalary());
            }
            tx.commit();
        } catch (HibernateException e) {
            if (tx != null)
                tx.rollback();
            e.printStackTrace();
        } finally {
            session.close();
        }
    }

    /* Method to UPDATE salary for an employee */
    public void updateEmployee(Integer EmployeeID, int salary) {
        Session session = factory.openSession();
        Transaction tx = null;
        try {
            tx = session.beginTransaction();
            Employee employee = (Employee) session.get(Employee.class, EmployeeID);
            employee.setSalary(salary);
            session.update(employee);
            tx.commit();
        } catch (HibernateException e) {
            if (tx != null)
                tx.rollback();
            e.printStackTrace();
        } finally {
            session.close();
        }
    }

    /* Method to DELETE an employee from the records */
    public void deleteEmployee(Integer EmployeeID) {
        Session session = factory.openSession();
        Transaction tx = null;
        try {
            tx = session.beginTransaction();
            Employee employee = (Employee) session.get(Employee.class, EmployeeID);
            session.delete(employee);
            tx.commit();
        } catch (HibernateException e) {
            if (tx != null)
                tx.rollback();
            e.printStackTrace();
        } finally {
            session.close();
        }
    }
}