hbm2java - ObjectRequired for nullable fields

Duncan · **Joined:** Tue Jan 06, 2004 12:34 pm **Posts:** 1

Hi,
I'm currently investigating using Middlegen and hbm2java to generate hbm files and java code based on an existing schema. I am using version 2.0.2 of Hibernate extensions built October 2003

I have encountered problems with the definition of native types for nullable columns by hbm2java. For example if I have an int column which is not part of any constraint and is nullable I (and I think Hibernate) would expect this column to be mapped to java.lang.Integer in the generated java class - however I get an int.

Looking at ClassMapping::initWith() below you can see that for properties 'nullable' is evaluated but not used in the call to getFieldType() and is subsequently defaulted to false. Is this a simple bug or am I missing something?

Code:

         
         // handle in a different way id and properties...
         // ids may be generated and may need to be of object type in order to support
         // the unsaved-value "null" value.
         // Properties may be nullable (ids may not)
         if (property == id)  {...         
         } 
         else {
            String notnull = property.getAttributeValue("not-null");
            // if not-null property is missing lets see if it has been
            // defined at column level
            if(notnull == null) {
               Element column = property.getChild("column");
               if(column != null)
                  notnull = column.getAttributeValue("not-null");
            }
            
boolean nullable = ( notnull == null || notnull.equals("false") );
            boolean key = property.getName().startsWith("key-"); //a composite id property
            ClassName t = getFieldType(type);
            addImport(t);
            Field stdField =new Field(name, t, nullable && !key, key, false, metaForProperty);
            fields.add(stdField );

max · **Posted:** Wed Jan 07, 2004 4:52 am

use "java.lang.Integer" instead of just "int" as the type.

david · **Posted:** Wed Jan 07, 2004 10:13 am

The next version of Hibernate Middlegen plugin has the ability to use a specialised JavaTypeMapper which can be applied to avoid it generating native types for nullable fields. Its all in CVS (Middlegens') if you want to play. The code includes a custom JavaTypeMapper which can be plugged in that has this feature.