IsEmpty inside Iterate Tag

Hi,

I am having trouble determining the correct syntax to use with the isEmpty tag when iterating over a list. My program has a large list of objects with potentially null fields and I need to customize my insert statements based on whether or not a particular object has a certain field set to null.

Here is my SqlMap file:

    <insert id="createObject" parameterClass="java.util.List">
        Insert into someTable (field1, field2, field3)
        Values <iterate conjunction=", ">
        (#[].field1#, <isNotEmpty property="[].field2">#[].field2#, </isNotEmpty><isEmpty property="[].field2">NULL, </isEmpty> #[].field3#)
    </iterate>
    </insert>

When I call this sqlMap, the isNotEmpty tag throws the following exception:

SqlMapClient operation; uncategorized SQLException for SQL []; SQL state [null]; error code [0];
--- The error occurred in org/someFile/mySQL.xml.
--- The error occurred while preparing the mapped statement for execution.
--- Check the Mapping.
--- Check the createObject parameter map.
Cause: com.ibatis.common.beans.ProbeException: Error getting ordinal list from JavaBean. Cause java.lang.StringIndexOutOfBoundsException: String index out of range: -1; nested exception is com.ibatis.common.jdbc.exception.NestedSQLException:
java.lang.StringIndexOutOfBoundsException: String index out of range: -1

What syntax should I use in the isNotEmpty property field to avoid this exception? When I remove the isNotEmpty and isEmpty tags, the sql statement executes successfully. I tried using property="#[].field2#" and property="field2" but neither of those statements fixed the problem.

Thanks!