How to overwrite the Solr document field? - solr

Question

<arr name="itemDescSpell">
<str>Cable Tie, 4.0L (102mm), Miniature, Nyl</str>
<str>Cable Tie, 4.0L (102mm), Miniature, Nyl</str>
</arr>
itemDescSpell which is copyField which causing error when Solr Document is updated each time. I don't want to make the field as multiValued="true"
in schema , copyField is defined like below
<field name="itemDescSpell" type="textSpell"/>
<copyField source="description" dest="itemDescSpell"/>
The error is:
multiple values encountered for non multiValued field itemDescSpell.
Is anybody able to help me to solve this problem via SolrJ, while keeping this field type as textSpell?

Answer 1

Try using a custom UpdateRequestProcessor to overwrite the value present in the itemDescSpell field . Solr will throw the exception you get when a copyfield destination is already populated , so what you want to do is remove the copyField line from your schema and add a custom UpdateRequestProcessor to your config that could look like this :
public class CustomFactory extends UpdateRequestProcessorFactory {
#Override
public UpdateRequestProcessor getInstance(SolrQueryRequest req, SolrQueryResponse rsp, UpdateRequestProcessor next) {
return new Custom(next);
}
public class Custom extends UpdateRequestProcessor {
public Custom(UpdateRequestProcessor next){
super(next);
}
#Override
public void processAdd(AddUpdateCommand cmd) throws IOException {
cmd.solrDoc.setField("foo",cmd.solrDoc.getFieldValue("bar"));
}
}
}
This is NOT production ready code but it should give you an idea on how the final code should look. To customize the field values you can override the init method on the factory and pass those in the config.
The main difference is that solr uses addField when encountering copyField, and this class uses setField