Adding an enum as a class property in HBM

Question

I am trying to create a class in HBM file which contains an Enum as a field.

The HBM is similar to this:

<class name="a.b.c.myObject" table="OBJECT" >
       <property name="myEnum" column="EXAMPLE" type="a.b.c.myEnum" />
</class>

and let's say that this is the Enum:

public enum myEnum{
    a, b, c;
}

The problem is that in the DB I expected to see the String value of that enum (a,b or c) but instead I got the raw data of that field.

How can I solve that?

Answer 1

Here is the solution with Hibernate 3.6.x :

<class name="a.b.c.myObject" table="OBJECT">
  <property name="myEnum" column="EXAMPLE">
    <type name="org.hibernate.type.EnumType">
      <param name="enumClass">a.b.c.myEnum</param>
    </type>       
  </property>
</class>

Answer 2

Similar to @monim answer, but more elegant way:

<class name="a.b.c.myObject" table="OBJECT">
    <property name="myEnum" column="EXAMPLE">
        <type name="org.hibernate.type.EnumType">
            <param name="enumClass">a.b.c.myEnum</param>
            <param name="useNamed">true</param>
        </type>       
    </property>
</class>

Answer 3

1) Easy solution: use Hibernate Annotations instead of XML-based mappings. Enum support is built-in:

@Entity
public class MyObject {
  @Enumerated(EnumType.STRING)
  @Column(name="EXAMPLE")
  private MyEnum myEnum;
}

2) If you can't use annotations, you can still use the EnumType they provide in XML-based mappings. You do need to have appropriate hibernate-annotations.jar in your classpath during deployment but there's no compile-time dependency:

<class name="a.b.c.myObject" table="OBJECT" >
  <property name="myEnum" column="EXAMPLE" type="org.hibernate.type.EnumType"/>
</class>

Answer 4

Just editing @Emmanuel Bourg answer and adding another <param> like this:

<class name="a.b.c.myObject" table="OBJECT">
    <property name="myEnum" column="EXAMPLE">
        <type name="org.hibernate.type.EnumType">
            <param name="enumClass">a.b.c.myEnum</param>
            <param name="type">12</param>
        </type>       
    </property>
</class>

12 is equivilant to java.sql.Types.VARCHAR