Mapping <bean class="org.compass.gps.device.jdbc.mapping.DataColumnToPropertyMapping"> <property name="columnName" value="last_price_date"/> <property name="propertyName" value="lastPriceDate"/> <property name="converter" value="date"/> </bean> ResultSetRowMarshallHelper.marshallMappedData(ResultSet rs) does: String value = dialect.getStringValue(rs, ctpMapping); This string value is passed into org.compass.core.lucene.LuceneResource.addProperty(String name, Object value) where addProperty in turn calls into converter: String strValue = converter.toString(value, propertyMapping); Converter in my case is org.compass.core.converter.basic.DateConverter. That delegates to SimpleDateFormat.format (or something similar) and that throws java.lang.IllegalArgumentException because object is not of type Date or Number but a String. A better approach would be IMHO to: 1. Allow user to specify the type of the column 2. Look up type of the column from ResultSetMetaData and call a correct getter on resultSet based on that. It also calls for changes in the ResultSetRowMarshallHelper to pass around Object value vs. String value. Dmitry