Unknown state or association field with @Transformation

Question

I have a class that uses a Transformation mapping for the IP address field. The IP address is the string dot notation in the class, but is a long integer in the database. My entity class looks like this:
@Entity
@Table(name="LOCATION_MAP")
public class LocationMap implements Serializable {
bq.      @Transformation \\          @ReadTransformer(IPAttributeTransformer.class) \\          @WriteTransformer(IPAttributeTransformer.class) \\          @Column(name="IP_ADDR") \\          protected String ipAddr; \\          ...
IPAttributeTransformer is a class that implements both org.eclipse.persistence.mappings.transformers.AttributeTransfomer and org.eclipse.persistence.mappings.transformers.FieldTransformer.
When I attempt to execute the query, "select location.ipAddr from LocationMap location", it gives me the error Error compiling the query [(select location.ipAddr from LocationMap location|http://select location.ipAddr from LocationMap location]), line 1, column 16: unknown state or association field (ipAddr) of class (com.example.LocationMap).
If I comment out the @Transformation, @ReadTransformer, and @WriteTransformer annotations, then I don't get the error, but of course I also don't get the transformed IP address.
This mapping worked with TopLink 10g and the XML descriptor file, but I am trying to migrate to 11g and JPA with annotations.
Josh Davis
Edited by: user603300 on Mar 12, 2009 12:22 PM, forum software tried to turn square brackets into URL's.

Answer 1

Hello Ryan,
The example I have does the following:
@ReadTransformer(method="buildNormalHours")
@WriteTransformers({
@WriteTransformer(method="getStartTime", column=@Column(name="START_TIME")),
@WriteTransformer(method="getEndTime", column=@Column(name="END_TIME"))
@Property(name="attributeName", value="normalHours")
protected Time[] getNormalHours() {
return normalHours;
where buildNormalHours looks like:
/** IMPORTANT: This method builds the value but does not set it.
* The mapping will set it using method or direct access as defined in the descriptor.
public Time[] buildNormalHours(Record row, Session session) {
Time[] hours = new Time[2];
/** This conversion allows for the database type not to match, i.e. may be a Timestamp or String. */
hours[0] = (Time) session.getDatasourcePlatform().convertObject(row.get("START_TIME"), java.sql.Time.class);
hours[1] = (Time) session.getDatasourcePlatform().convertObject(row.get("END_TIME"), java.sql.Time.class);
return hours;
Another uses a transformer class for the read:
@ReadTransformer(transformerClass=org.eclipse.persistence.testing.models.jpa.advanced.AdvancedReadTransformer.class)
which extends the org.eclipse.persistence.mappings.transformers.AttributeTransformer class and implements a buildAttributeValue method.
Hope this helps,
Chris