Use Combined Fields As Primary Key : Entity Primary Key « EJB3 « Java

1. Java
2. EJB3
3. Entity Primary Key

Use Combined Fields As Primary Key

File: EmployeeService.java


import java.util.Collection;

import javax.ejb.Remove;
import javax.ejb.Stateless;
import javax.persistence.EntityManager;
import javax.persistence.PersistenceContext;
import javax.persistence.Query;

@Stateless
public class EmployeeService implements EmployeeServiceLocal, EmployeeServiceRemote {
  @PersistenceContext(unitName="EmployeeService")
  EntityManager em;
  
  public EmployeeService() {
  }
  public void doAction(){
    Employee cust = new Employee();
    cust.setFirstName("B");
    cust.setLastName("B");
    cust.setSsn(9999999);    
    
    em.persist(cust);
    em.flush();
    
  }


}

    


File: EmployeeServiceLocal.java



import java.util.Collection;

import javax.ejb.Local;

@Local
public interface EmployeeServiceLocal {
    public void doAction();

}



File: EmployeeServiceRemote.java




import java.util.Collection;

import javax.ejb.Remote;

@Remote
public interface EmployeeServiceRemote{
  public void doAction();  

}



File: Employee.java

import java.io.Serializable;

import javax.persistence.Column;
import javax.persistence.Entity;
import javax.persistence.Id;
import javax.persistence.IdClass;
import javax.persistence.Table;

@Entity
@Table(name="EMP")
@IdClass(EmployeePK.class)
public class Employee implements Serializable {
  private String firstName;
  private String lastName;
  private long ssn;

  public String getFirstName() { return firstName; }
  public void setFirstName(String firstName) { this.firstName = firstName; }

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

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

  public String toString() {
    return "Employee : " + getFirstName() ;
  }
}


File: EmployeePK.java

public class EmployeePK implements java.io.Serializable {
  private String lastName;

  private long ssn;

  public EmployeePK() {
  }

  public EmployeePK(String lastName, long ssn) {
    this.lastName = lastName;
    this.ssn = ssn;
  }

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

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

  public long getSsn() {
    return ssn;
  }

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

  public boolean equals(Object obj) {
    if (obj == this)
      return true;
    if (!(obj instanceof EmployeePK))
      return false;
    EmployeePK pk = (EmployeePK) obj;
    if (!lastName.equals(pk.lastName))
      return false;
    if (ssn != pk.ssn)
      return false;
    return true;
  }

  public int hashCode() {
    return lastName.hashCode() + (int) ssn;
  }
}


File: Main.java

import java.util.Collection;

import javax.naming.InitialContext;


public class Main {

  public static void main(String[] a) throws Exception {

    EmployeeServiceRemote service = null;

    // Context compEnv = (Context) new InitialContext().lookup("java:comp/env");

    // service = (HelloService)new InitialContext().lookup("java:comp/env/ejb/HelloService");
    service = (EmployeeServiceRemote) new InitialContext().lookup("EmployeeService/remote");
    
    

    
    
    service.doAction();

  }

}


File: jndi.properties

java.naming.factory.initial=org.jnp.interfaces.NamingContextFactory
java.naming.factory.url.pkgs=org.jboss.naming:org.jnp.interfaces
java.naming.provider.url=localhost:1099




           
       

EJB-UseCombinedFieldsAsPrimaryKey.zip( 4,489 k)

Related examples in the same category

1.

EJB Tutorial from JBoss: Primary Key Composition