The Java Persistence API

TheJava Persistence API (JPA)was introduced to Java EE in version 5 of the specification. Like its name implies, it is used to persist data to a relational database management system. JPA is a replacement for the Entity Beans that were used in J2EE. Java EE Entities are regular Java classes; the Java EE container knows these classes are Entities because they are decorated with the@Entityannotation. Let's look at an Entity mapping to theCUSTOMERtable in theCUSTOMERDBdatabase:

package net.ensode.javaee8book.jpaintro.entity; 
 
import java.io.Serializable; 
 
import javax.persistence.Column; 
import javax.persistence.Entity; 
import javax.persistence.Id; 
import javax.persistence.Table; 
 
@Entity 
@Table(name = "CUSTOMERS") 
public class Customer implements Serializable 
{ 
  @Id 
  @Column(name = "CUSTOMER_ID") 
  private Long customerId; 
 
  @Column(name = "FIRST_NAME") 
  private String firstName; 
 
  @Column(name = "LAST_NAME") 
  private String lastName; 
 
...