Add weights to documents Lucene8+solr 8 while indexing - lucene

Question

I am working on migrating solr from 5.4.3 to 8.11 for one of my search apps and successfully upgraded to 7.7.3. But for further upgradations facing the order of the response data being changed than it was earlier. Here I am trying to use FunctionScoreQuery along with DoubleValuesSource since CustomScoreQuery is deprecated in 7.7.3 and removed in 8.
Below is my code snippet (now I am using solr 8.5.2 and Lucene 8.5.2)
public class CustomQueryParser extends QParserPlugin {
#Override
public QParser createParser(final String qstr, final SolrParams localParams, final SolrParams params,
final SolrQueryRequest req) {
return new MyParser(qstr, localParams, params, req);
}
private static class MyParser extends QParser {
private Query innerQuery;
private String queryString;
public MyParser(final String qstr, final SolrParams localParams, final SolrParams params,
final SolrQueryRequest req) {
super(qstr, localParams, params, req);
if (qstr == null || qstr.trim().length() == 0) {
this.queryString = DEFAULT_SEARCH_QUERY;
setString(this.queryString);
} else {
this.queryString = qstr;
}
try {
if (queryString.contains(":")) {
final QParser parser = getParser(queryString, "edismax", getReq());
this.innerQuery = parser.parse();
} else {
final QParser parser = getParser(queryString, "dismax", getReq());
this.innerQuery = parser.parse();
}
} catch (final SyntaxError ex) {
throw new RuntimeException("Error parsing query", ex);
}
}
#Override
public Query parse() throws SyntaxError{
final Query query = new MyCustomQuery(innerQuery);
final CustomValuesSource customValuesSource = new CustomValuesSource(queryString,innerQuery);
final FunctionScoreQuery fsq = FunctionScoreQuery.boostByValue(query, customValuesSource.fromFloatField("score"));
return fsq;
}
}
}
public class MyCustomQuery extends Query {
#Override
public Weight createWeight(final IndexSearcher searcher, final ScoreMode scoreMode, final float boost) throws IOException {
Weight weight;
if(query == null){
weight = new ConstantScoreWeight(this, boost) {
#Override
public Scorer scorer(final LeafReaderContext context) throws IOException {
return new ConstantScoreScorer(this,score(),scoreMode, DocIdSetIterator.all(context.reader().maxDoc()));
}
#Override
public boolean isCacheable(final LeafReaderContext leafReaderContext) {
return false;
}
};
}else {
weight = searcher.createWeight(query,scoreMode,boost);
}
return weight;
}
}
public class CustomValuesSource extends DoubleValuesSource {
#Override
public DoubleValues getValues(final LeafReaderContext leafReaderContext,final DoubleValues doubleValues) throws IOException {
final DoubleValues dv = new CustomDoubleValues(leafReaderContext);
return dv;
}
class CustomDoubleValues extends DoubleValues {
#Override
public boolean advanceExact(final int doc) throws IOException {
final Document document = leafReaderContext.reader().document(doc);
final List<IndexableField> fields = document.getFields();
for (final IndexableField field : fields) {
// total_score is being calculated with my own preferences
document.add(new FloatDocValuesField("score",total_score));
//can we include the **score** here?
this custom logic which includes score is not even calling.
}
}
}
I am trying for a long time but have not found a single working example. Can anybody help me and save me here.
Thank you,
Syamala.