what is an entity in hibernate?
Entity: In general entity is an object that has some distinct value. In a persistent storage mechanism, an entity is a business object. Each entity has an associated table in relational database. Each instance of the entity represents a row of the table.
Entity class is an annotated POJO (Plain Old java Object). Here are some points to be noted during writing entity class:
· Class must have constructor
· Create getter setter for each field
· Don?t define any field static or final.
Example:
Here is an entity class named Employee.java.It mapped the employee table.
package net.roseindia.table;
import javax.persistence.Column;
import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.Id;
import javax.persistence.Table;
import java.util.Date;
@Entity
@Table(name = "employee")
public class Employee {
@Id
@GeneratedValue
@Column(name = "emp_id")
private int id;
@Column(name = "name")
private String name;
@Column(name = "salary")
private int salary;
@Column(name = "date_of_join")
private Date dateOfJoin;
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 int getSalary() {
return salary;
}
public void setSalary(int salary) {
this.salary = salary;
}
public Date getDateOfJoin() {
return dateOfJoin;
}
public void setDateOfJoin(Date dateOfJoin) {
this.dateOfJoin = dateOfJoin;
}
}