| Methods Summary |
|---|
| public java.lang.Object | clone()Returns a clone of this query.
try {
return (Query)super.clone();
} catch (CloneNotSupportedException e) {
throw new RuntimeException("Clone not supported: " + e.getMessage());
}
|
| public org.apache.lucene.search.Query | combine(org.apache.lucene.search.Query[] queries)Expert: called when re-writing queries under MultiSearcher.
Create a single query suitable for use by all subsearchers (in 1-1
correspondence with queries). This is an optimization of the OR of
all queries. We handle the common optimization cases of equal
queries and overlapping clauses of boolean OR queries (as generated
by MultiTermQuery.rewrite() and RangeQuery.rewrite()).
Be careful overriding this method as queries[0] determines which
method will be called and is not necessarily of the same type as
the other queries.
HashSet uniques = new HashSet();
for (int i = 0; i < queries.length; i++) {
Query query = queries[i];
BooleanClause[] clauses = null;
// check if we can split the query into clauses
boolean splittable = (query instanceof BooleanQuery);
if(splittable){
BooleanQuery bq = (BooleanQuery) query;
splittable = bq.isCoordDisabled();
clauses = bq.getClauses();
for (int j = 0; splittable && j < clauses.length; j++) {
splittable = (clauses[j].getOccur() == BooleanClause.Occur.SHOULD);
}
}
if(splittable){
for (int j = 0; j < clauses.length; j++) {
uniques.add(clauses[j].getQuery());
}
} else {
uniques.add(query);
}
}
// optimization: if we have just one query, just return it
if(uniques.size() == 1){
return (Query)uniques.iterator().next();
}
Iterator it = uniques.iterator();
BooleanQuery result = new BooleanQuery(true);
while (it.hasNext())
result.add((Query) it.next(), BooleanClause.Occur.SHOULD);
return result;
|
| protected org.apache.lucene.search.Weight | createWeight(org.apache.lucene.search.Searcher searcher)Expert: Constructs an appropriate Weight implementation for this query.
Only implemented by primitive queries, which re-write to themselves.
throw new UnsupportedOperationException();
|
| public void | extractTerms(java.util.Set terms)Expert: adds all terms occuring in this query to the terms set. Only
works if this query is in its {@link #rewrite rewritten} form.
// needs to be implemented by query subclasses
throw new UnsupportedOperationException();
|
| public float | getBoost()Gets the boost for this clause. Documents matching
this clause will (in addition to the normal weightings) have their score
multiplied by b. The boost is 1.0 by default. return boost;
|
| public org.apache.lucene.search.Similarity | getSimilarity(org.apache.lucene.search.Searcher searcher)Expert: Returns the Similarity implementation to be used for this query.
Subclasses may override this method to specify their own Similarity
implementation, perhaps one that delegates through that of the Searcher.
By default the Searcher's Similarity implementation is returned.
return searcher.getSimilarity();
|
| public static org.apache.lucene.search.Query | mergeBooleanQueries(org.apache.lucene.search.Query[] queries)Expert: merges the clauses of a set of BooleanQuery's into a single
BooleanQuery.
A utility for use by {@link #combine(Query[])} implementations.
HashSet allClauses = new HashSet();
for (int i = 0; i < queries.length; i++) {
BooleanClause[] clauses = ((BooleanQuery)queries[i]).getClauses();
for (int j = 0; j < clauses.length; j++) {
allClauses.add(clauses[j]);
}
}
boolean coordDisabled =
queries.length==0? false : ((BooleanQuery)queries[0]).isCoordDisabled();
BooleanQuery result = new BooleanQuery(coordDisabled);
Iterator i = allClauses.iterator();
while (i.hasNext()) {
result.add((BooleanClause)i.next());
}
return result;
|
| public org.apache.lucene.search.Query | rewrite(org.apache.lucene.index.IndexReader reader)Expert: called to re-write queries into primitive queries. For example,
a PrefixQuery will be rewritten into a BooleanQuery that consists
of TermQuerys.
return this;
|
| public void | setBoost(float b)Sets the boost for this query clause to b. Documents
matching this clause will (in addition to the normal weightings) have
their score multiplied by b. // query boost factor
boost = b;
|
| public abstract java.lang.String | toString(java.lang.String field)Prints a query to a string, with field assumed to be the
default field and omitted.
The representation used is one that is supposed to be readable
by {@link org.apache.lucene.queryParser.QueryParser QueryParser}. However,
there are the following limitations:
- If the query was created by the parser, the printed
representation may not be exactly what was parsed. For example,
characters that need to be escaped will be represented without
the required backslash.
- Some of the more complicated queries (e.g. span queries)
don't have a representation that can be parsed by QueryParser.
|
| public java.lang.String | toString()Prints a query to a string.
return toString("");
|
| public org.apache.lucene.search.Weight | weight(org.apache.lucene.search.Searcher searcher)Expert: Constructs and initializes a Weight for a top-level query.
Query query = searcher.rewrite(this);
Weight weight = query.createWeight(searcher);
float sum = weight.sumOfSquaredWeights();
float norm = getSimilarity(searcher).queryNorm(sum);
weight.normalize(norm);
return weight;
|
