Example usage for org.apache.lucene.search LongValuesSource fromIntField

Introduction

In this page you can find the example usage for org.apache.lucene.search LongValuesSource fromIntField.

Prototype

public static LongValuesSource fromIntField(String field) 

Source Link

Document

Creates a LongValuesSource that wraps an int-valued field

Usage

From source file:org.apache.solr.handler.component.SubsetQueryPlugin.java

License:Apache License

@Override
public QParser createParser(String qstr, SolrParams localParams, SolrParams params, SolrQueryRequest req) {
    return new QParser(qstr, localParams, params, req) {

        @Override/*w ww.  j a v a 2 s. c o m*/
        public Query parse() throws SyntaxError {
            String fieldName = Preconditions.checkNotNull(localParams.get(SETVAL_FIELD_NAME));
            String countFieldName = Preconditions.checkNotNull(localParams.get(COUNT_FIELD_NAME));
            boolean allowMissingValues = Boolean
                    .parseBoolean(Preconditions.checkNotNull(localParams.get(MISSING_VAL_ALLOWED)));
            String wildcardToken = localParams.get(WILDCARD_CHAR);

            LongValuesSource minimumNumberMatch = LongValuesSource.fromIntField(countFieldName);
            Collection<Query> queries = new ArrayList<>();

            String fieldVals = Preconditions.checkNotNull(localParams.get(SETVAL_PARAM_NAME));
            for (String v : fieldVals.split(",")) {
                queries.add(new TermQuery(new Term(fieldName, v)));
            }
            if (wildcardToken != null && !wildcardToken.equals("")) {
                queries.add(new TermQuery(new Term(fieldName, wildcardToken)));
            }
            if (allowMissingValues) {
                // To construct this query we need to do a little trick tho construct a test for an empty field as follows:
                // (*:* AND -fieldName:*) ==> parses as: (+*:* -fieldName:*)
                // It is a feature of Lucene that pure negative queries are not allowed (although Solr allows them as a top level construct)
                // therefore we need to AND with *:*
                // We can then pass this BooleanQuery to the CoveringQuery as one of its allowed matches.
                BooleanQuery.Builder builder = new BooleanQuery.Builder();
                builder.add(new BooleanClause(new MatchAllDocsQuery(), BooleanClause.Occur.SHOULD));
                builder.add(new BooleanClause(new WildcardQuery(new Term(fieldName, "*")),
                        BooleanClause.Occur.MUST_NOT));

                queries.add(builder.build());
            }
            return new CoveringQuery(queries, minimumNumberMatch);
        }
    };
}

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