Hibernate map enum to varchar

Question

Suppose I have this enum:

public enum TestEnum { EXAMPLE, FURTHER_EXAMPLE, LAST_EXAMPLE }

With this mapping in the .hbm:

<property name="testEnum" column="TEST_COLUMN">
    <type name="org.hibernate.type.EnumType">
        <param name="enumClass">p.a.c.k.TestEnum</param>
    </type>
 </property>

The enum is sent to the database as 0, 1, 2. I'd like the values to be instead stored as EXAMPLE, FURTHER_EXAMPLE or LAST_EXAMPLE in a varchar column.

How can I map enum to a varchar column?

Answer 1

Maybe this is more descriptive

<param name="useNamed">true</param>

Answer 2

Add this as a parameter of EnumType:

<param name="type">12</param>

This is because 12 is equivalent to java.sql.Types.VARCHAR

Answer 3

If you want to store any enum's value as varchar in database, please follow below steps.

1. Hibernate provides an UserTpe interface. We need to create a class which implements UserType interface.

   import java.io.Serializable;
   import java.sql.PreparedStatement;
   import java.sql.ResultSet;
   import java.sql.SQLException;
   import java.sql.Types;
   
   import org.hibernate.HibernateException;
   import org.hibernate.usertype.UserType;
   
   public class EnumUserType<E extends Enum<E>> implements UserType {
      private Class<E> clazz = null;
   
      protected EnumUserType(Class<E> c) {
          this.clazz = c;
      }
   
      private static final int[] SQL_TYPES = { Types.VARCHAR };
   
      public int[] sqlTypes() {
              return SQL_TYPES;
      }
   
      public Class returnedClass() {
          return clazz;
      }
   
      public Object nullSafeGet(ResultSet resultSet, String[] names, Object owner)
           throws HibernateException, SQLException {
   
          String name = resultSet.getString(names[0]);
   
          E result = null;
          if (!resultSet.wasNull()) {
              result = Enum.valueOf(clazz, name);
   
          }
          return result;
      }
   
      public void nullSafeSet(PreparedStatement preparedStatement, Object value,
           int index) throws HibernateException, SQLException {
   
          if (null == value) {
              preparedStatement.setNull(index, Types.VARCHAR);
          } else {
              preparedStatement.setString(index, ((Enum) value).name());
          }
      }
   
      public Object deepCopy(Object value) throws HibernateException {
          return value;
      }
   
      public boolean isMutable() {
          return false;
      }
   
      public Object assemble(Serializable cached,Object owner) throws HibernateException {
          return cached;
      }
   
      public Serializable disassemble(Object value) throws HibernateException {
          return (Serializable) value;
      }
   
      public Object replace(Object original, Object target, Object owner)
           throws HibernateException {
          return original;
      }
   
      public int hashCode(Object x) throws HibernateException {
          return x.hashCode();
      }
   
      public boolean equals(Object x, Object y) throws HibernateException {
          if (x == y)
              return true;
          if (null == x || null == y)
              return false;
          return x.equals(y);
      }
   }
   

2. Suppose I have a EncryptionStatus Enum.

   import java.io.Serializable;
   import com.google.gwt.user.client.rpc.IsSerializable;
   
   public enum EncryptionStatus implements IsSerializable, Serializable {
       PLAIN, HASH, RE_HASH, SUPER_HASH, SUPER_REHASH, OPEN, ENCRYPT, RE_ENCRYPT
   }
   

3. We need to create a class which extends our created EnumUserType>.

   public class EncryptionStatusType extends EnumUserType<EncryptionStatus>{
   
      public  EncryptionStatusType() {     
          super(EncryptionStatus.class);
      }
   }
   

4. Now we need to map above created class in hbm.xml file in stead of Enum mapping which store enum value as varchar in the database. For Example,

<property name="secureStatus" type="com.nextenders.facadeimplementation.util.userenum.EncryptionStatusType" column="secure_status" />

Answer 4

You can use annotations like this:

public class MyClass {
    TestEnum testEnum;
    @column(name="TEST_COLUMN")
    @Enumerated(EnumType.STRING)
    public TestEnum getTestEnum(){
        this.testEnum;
    }
}