create hibernate java project in eclipse

Creating a Hibernate Java Project in Eclipse

In this article, we will discuss how to create a simple Hibernate project in Eclipse. We will follow a step-by-step approach to understand the basics of Hibernate and its usage.

Before we begin, let's create a simple persistent class called `Employee`. In Hibernate, the application programmer cannot use proxies for lazy association fetching. This means that we need to declare the getter and setter methods explicitly.

Here is an example of how our `Employee` class would look like:

```java

public class Employee {

private int id;

private String name;

private String department;

public Employee() {}

public Employee(int id, String name, String department) {

this.id = id;

this.name = name;

this.department = department;

}

public int getId() {

return id;

}

public void setId(int id) {

this.id = id;

}

public String getName() {

return name;

}

public void setName(String name) {

this.name = name;

}

public String getDepartment() {

return department;

}

public void setDepartment(String department) {

this.department = department;

}

```

As you can see, we have declared a no-arg constructor and getter and setter methods for each attribute. This is necessary because Hibernate recognizes the method by its name.

Next, let's create a servlet that will pass an employee ID as a request parameter and print out the employee information from the database using Hibernate.

Here is an example of how our servlet would look like:

```java

import javax.servlet.ServletException;

import javax.servlet.http.HttpServlet;

import javax.servlet.http.HttpServletRequest;

import javax.servlet.http.HttpServletResponse;

import java.io.IOException;

public class EmployeeServlet extends HttpServlet {

protected void doGet(HttpServletRequest request, HttpServletResponse response)

throws ServletException, IOException {

int id = Integer.parseInt(request.getParameter('id'));

Session session = HibernateUtil.getSessionFactory().getCurrentSession();

session.beginTransaction();

Employee employee = (Employee) session.get(Employee.class, id);

if (employee != null) {

response.getWriter().println('Employee ID: ' + employee.getId());

response.getWriter().println('Name: ' + employee.getName());

response.getWriter().println('Department: ' + employee.getDepartment());

} else {

response.getWriter().println('Employee not found');

}

session.getTransaction().commit();

}

```

In this servlet, we are using the `HibernateUtil` class to get a session factory and start a transaction. We then use the `session.get()` method to retrieve an employee object from the database based on the ID passed as a request parameter.

Finally, let's create a Hibernate configuration file (`hibernate.cfg.xml`) that will contain our mapping information:

```xml

'-//Hibernate/Hibernate Configuration DTD//EN'

'http://www.hibernate.org/dtd/hibernate-configuration-3.0.dtd'>

com.mysql.cj.jdbc.Driver

jdbc:mysql://localhost:3306/employees

root

1

org.hibernate.dialect.MySQLDialect

org.hibernate.cache.internal.NoCacheProvider

```

In this file, we are specifying our database connection settings, including the driver class, URL, username, and password. We are also setting the SQL dialect to MySQL.

That's it! With these steps, you have successfully created a simple Hibernate project in Eclipse. You can run your servlet by using the `mvn tomcat7:run` command and access it through a web browser.

Note that this is just a basic example, and there are many more features and configurations available in Hibernate that you may want to explore further.

Create hibernate java project in eclipse