datetimeoffset hibernate mapping

问题:

I'm trying to use hibernate with ms sql server and have difficulties mapping the sql type datetimeoffset to java. If I try to set the mapping type in the reverse engineering configuration with:

I get an error saying sth. like org.hibernate.MappingException: jdbc-type: microsoft.sql.Types.DATETIMEOFFSET is not a known JDBC Type nor a valid number

I guess only the detault jdbc types can be used in this context.

Any ideas about how to solve this issue?

回答1:

Your can provide a custom Hibernate user type. For example by implementing org.hibernate.type.MutableType.

Refer Hibernate Reference for more information.

回答2:

An example custom type implementation for DatetimeOffset type can be seen below, on top of this you need to set the sql-type directive in the reverse engineering configuration file accordingly.

<type-mapping>
 <sql-type jdbc-type="-155" hibernate-type="package.x.y.z.DatetimeOffsetType"></sql-type> 
 </type-mapping>

The jdbc-type= -155 is for ms sql server datetimeoffset type.

An example implementation:

public class DatetimeOffsetType  implements UserType  {

static {
    initializeMethods();
}

private static Method methodSetDateTimeOffset;

@Override
public Object assemble(Serializable arg0, Object arg1)
        throws HibernateException {
    return arg0;
}

@Override
public Object deepCopy(Object value) throws HibernateException {
    DateTimeOffset dateTimeOffset = (DateTimeOffset)value;
    return (value == null) ? null :
        DateTimeOffset.valueOf(dateTimeOffset.getTimestamp(), dateTimeOffset.getMinutesOffset());
}

@Override
public Serializable disassemble(Object arg0) throws HibernateException {
    return (Serializable)arg0;
}

@Override
public boolean equals(Object arg0, Object arg1) throws HibernateException {
    if(arg0 == null || ! (arg0 instanceof DateTimeOffset) || arg1 == null || ! (arg1 instanceof DateTimeOffset)) {
        return false;
    }

    return arg0.equals(arg1);
}

@Override
public int hashCode(Object arg0) throws HibernateException {
    return arg0.hashCode();
}

@Override
public boolean isMutable() {
    return true;
}

@Override
public Object nullSafeGet(ResultSet resultSet, String[] names, Object owner)
        throws HibernateException, SQLException {
        return (DateTimeOffset) resultSet.getObject(names[0]);
}

@Override
public void nullSafeSet(PreparedStatement preparedStatement, Object value, int index)
        throws HibernateException, SQLException {
    // TODO check casting
    if(preparedStatement instanceof SQLServerPreparedStatement) {
        SQLServerPreparedStatement  sqlServerPreparedStatement  = (SQLServerPreparedStatement)preparedStatement;
         sqlServerPreparedStatement.setDateTimeOffset(index, (DateTimeOffset) value);
    }else {

         try {
             C3P0ProxyStatement proxyStatement = (C3P0ProxyStatement)preparedStatement;
             (proxyStatement).rawStatementOperation(methodSetDateTimeOffset,C3P0ProxyStatement.RAW_STATEMENT, new Object[] {index,(DateTimeOffset) value});
        } catch (Exception e) {

        }

    }
}

@Override
public Object replace(Object original, Object target, Object arg2)
        throws HibernateException {
    // TODO Auto-generated method stub
    System.out.println("replace");
    return null;
}

@Override
public Class<DateTimeOffset> returnedClass() {
    return DateTimeOffset.class;
}

@Override
public int[] sqlTypes() {
    return new int[] {microsoft.sql.Types.DATETIMEOFFSET}; //-155
}

private static void initializeMethods() {
    try {
        final Class c = Class.forName("com.microsoft.sqlserver.jdbc.SQLServerPreparedStatement");
        methodSetDateTimeOffset = c.getMethod("setDateTimeOffset", new Class[] {Integer.TYPE,DateTimeOffset.class});
    } catch (Exception e) {
        // TODO: handle exception
        e.printStackTrace();
    }
}