JPA 2.0 enums with custom values

Let's consider we have this enum

---

public enum EmpType {

FULL_TIME("e1"), PART_TIME("e2");

private String val;

private EmpType(String val) {

this.val = val;

}

@Override

public String toString() {

return val;

}

}

And the entity

---

@Entity
@NamedQueries({
@NamedQuery(name="Employee.findByEmployeeType", query="SELECT e FROM Employee e WHERE e.employeeType = ?1")
})

@Access(AccessType.FIELD)

public class Employee implements Serializable {

private static final long serialVersionUID = 1L;

@Id
@GeneratedValue(strategy = GenerationType.AUTO)
private Long id;

@Transient
private EmpType empType;


public Long getId() {

return id;

}


public void setId(Long id) {

this.id = id;

}


public EmpType getEmpType() {

return empType;

}


public void setEmpType(EmpType empType) {

this.empType = empType;

}


@Access(AccessType.PROPERTY)
@Column(name="employee_type")
protected String getEmployeeType() {

return empType.toString();

}


protected void setEmployeeType(String employeeType) {

for ( EmpType empType : EmpType.values() ) {

if ( empType.toString().equals(employeeType)){

this.empType = empType;

}

}

}


@Override
public String toString() {

return " ID : " + id + ", employee type : " + empType;

}


}


Note : Please checkout how i'm using @Access annotations at two different places, they are mandatory.


public class Main {


public static void main(String[] args) {

Main m = new Main();

Employee e = new Employee();

e.setEmpType(EmpType.PART_TIME);

em.persist(e); // assume we are persisting this entity


m.executeQuery(EmpType.PART_TIME);


}


public void executeQuery(EmpType emptType) {

EntityManagerFactory emf = Persistence.createEntityManagerFactory("PrepApp1PU");

EntityManager em = emf.createEntityManager();


Query query = em.createNamedQuery("Employee.findByEmployeeType");

query.setParameter(1, emptType.toString());

List list = query.getResultList();

System.out.println ( list.get(0) );


}


}




the above code will save entity as follows


ID EMPLOYEE_TYPE

1 e2


Also please carefully checkout how i'm searching employees based on enums. Also carefully checkout getEmployeeType(), setEmployeeType method signatures



the executeQuery method will print this

ID : 1, employee type : e2