Hibernate create POJO classes
In this tutorial you will learn how to create a POJO class in Hibernate.
POJO (Plain Old Java Object) is a programming model that follow some simple rules (not required to follow these rules hardly) to create a classes that implements the entities of the business problem. These can be as follows :
- Implement a default (no-argument) constructor : There must be a default constructor in a POJO class that are instantiated by the Hibernate using the Constructor.newInstance()
- Give(optional) an identifier property : It is an optional property that you can provide in POJO class because it is mapped as a primary key in the database table however, if you don't give this property Hibernate will maintain the track of object identifiers internally. Type of id can be of any primitive type.
- Should be prefer(optional) a non-final classes : Declaring a final class as well as public final methods should be avoidable because hibernate's feature proxies depends upon the POJO classes. If you would like to use a public final method with a class you must have to disable the proxying by setting lazy='false' explicitly at the time of use of proxies for lazy association fetching.
- Declare a setter and getter methods with their field names.
Example :
Here I am giving an example of POJO class. This class contains some fields using which I have created setter and getter methods. I have also created a default constructor. A simple dummy POJO class example is as follows :
package roseindia;
public class Employee
{
private long empId;
private String empName;
public Employee() {
}
public Employee(String empName) {
this.empName = empName;
}
public long getEmpId() {
return this.empId;
}
public void setEmpId(long empId) {
this.empId = empId;
}
public String getEmpName() {
return this.empName;
}
public void setEmpName(String empName) {
this.empName = empName;
}
}
