Java Tutorial/EJB3/Entity Lifecycle

Entity Bean Lifecycle: PostLoad

File: Customer.java

import javax.persistence.Entity;
import javax.persistence.Id;
import javax.persistence.PostLoad;
@Entity
public class Customer implements java.io.Serializable {
  private String firstName;
  private String lastName;
  @Id
  private long ssn;
  public String getFirstName() {
    return firstName;
  }
  public void setFirstName(String firstName) {
    this.firstName = firstName;
  }

  public String getLastName() {
    return lastName;
  }
  public void setLastName(String lastName) {
    this.lastName = lastName;
  }

  public long getSsn() {
    return ssn;
  }
  public void setSsn(long ssn) {
    this.ssn = ssn;
  }

  @PostLoad
  public void postLoad()
  {
     System.out.println("@PostLoad");
  }
}

Entity Bean Lifecycle: PostPersist

File: EmployeeBean.java

import java.util.List;
import javax.ejb.Stateless;
import javax.persistence.EntityManager;
import javax.persistence.PersistenceContext;
@Stateless
public class EmployeeBean implements EmployeeServiceLocal, EmployeeServiceRemote {
  @PersistenceContext(unitName="EmployeeService") private EntityManager manager;
  public void doAction(){
    Customer cust = new Customer();
    cust.setLastName("Bond");
    cust.setSsn(123456789L);
    manager.persist(cust);
    
    System.out.println("Saved");
    
    List<Customer> list =  manager.createQuery("FROM Customer res").getResultList();
    
    System.out.println(list.size());
  }
}

Entity Bean Lifecycle: PostRemove

File: Customer.java

import javax.persistence.Entity;
import javax.persistence.Id;
import javax.persistence.PostRemove;
@Entity
public class Customer implements java.io.Serializable {
  private String firstName;
  private String lastName;
  @Id
  private long ssn;
  public String getFirstName() {
    return firstName;
  }
  public void setFirstName(String firstName) {
    this.firstName = firstName;
  }

  public String getLastName() {
    return lastName;
  }
  public void setLastName(String lastName) {
    this.lastName = lastName;
  }

  public long getSsn() {
    return ssn;
  }
  public void setSsn(long ssn) {
    this.ssn = ssn;
  }
  @PostRemove
  public void postRemove()
  {
     System.out.println("@PostRemove");
  }
}

Entity Bean Lifecycle: PostUpdate

File: EmployeeBean.java

import java.util.List;
import javax.ejb.Stateless;
import javax.persistence.EntityManager;
import javax.persistence.PersistenceContext;
@Stateless
public class EmployeeBean implements EmployeeServiceLocal, EmployeeServiceRemote {
  @PersistenceContext(unitName="EmployeeService") private EntityManager manager;
  public void doAction(){
    Customer cust = new Customer();
    cust.setLastName("Bond");
    cust.setSsn(1L);
    manager.persist(cust);
    
    System.out.println("Saved");
    
    cust = manager.find(Customer.class,1L);
    System.out.println(cust.getLastName());
    
    cust.setLastName("new name");
    
    manager.persist(cust);
    
    cust = manager.find(Customer.class,1L);
    System.out.println(cust.getLastName());
  }
}

Entity Bean Lifecycle: PrePersist

File: EmployeeBean.java

import java.util.List;
import javax.ejb.Stateless;
import javax.persistence.EntityManager;
import javax.persistence.PersistenceContext;
@Stateless
public class EmployeeBean implements EmployeeServiceLocal, EmployeeServiceRemote {
  @PersistenceContext(unitName="EmployeeService") private EntityManager manager;
  public void doAction(){
    Customer cust = new Customer();
    cust.setLastName("Bond");
    cust.setSsn(123456789L);
    manager.persist(cust);
    
    System.out.println("Saved");
    
    List<Customer> list =  manager.createQuery("FROM Customer res").getResultList();
    
    System.out.println(list.size());
  }
}

Entity Bean Lifecycle: PreRemove

File: EmployeeBean.java

import java.util.List;
import javax.ejb.Stateless;
import javax.persistence.EntityManager;
import javax.persistence.PersistenceContext;
@Stateless
public class EmployeeBean implements EmployeeServiceLocal, EmployeeServiceRemote {
  @PersistenceContext(unitName="EmployeeService") private EntityManager manager;
  public void doAction(){
    Customer cust = new Customer();
    cust.setLastName("Bond");
    cust.setSsn(1L);
    manager.persist(cust);
    
    System.out.println("Saved");
    
    cust = manager.find(Customer.class,1L);
    System.out.println(cust.getLastName());
    
    cust.setLastName("new name");
    
    manager.persist(cust);
    
    cust = manager.find(Customer.class,1L);
    System.out.println(cust.getLastName());
    
    manager.remove(cust);
  }
}

Entity Bean Lifecycle PreUpdate

File: EmployeeBean.java

import java.util.List;
import javax.ejb.Stateless;
import javax.persistence.EntityManager;
import javax.persistence.PersistenceContext;
@Stateless
public class EmployeeBean implements EmployeeServiceLocal, EmployeeServiceRemote {
  @PersistenceContext(unitName="EmployeeService") private EntityManager manager;
  public void doAction(){
    Customer cust = new Customer();
    cust.setLastName("Bond");
    cust.setSsn(1L);
    manager.persist(cust);
    
    System.out.println("Saved");
    
    cust = manager.find(Customer.class,1L);
    System.out.println(cust.getLastName());
    
    cust.setLastName("new name");
    
    manager.persist(cust);
    
    cust = manager.find(Customer.class,1L);
    System.out.println(cust.getLastName());
  }
}