/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You under the Apache License, Version 2.0
* (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
using System;
using IndexReader = Lucene.Net.Index.IndexReader;
using Term = Lucene.Net.Index.Term;
using ToStringUtils = Lucene.Net.Util.ToStringUtils;
namespace Lucene.Net.Search
{
/// Implements the wildcard search query. Supported wildcards are *, which
/// matches any character sequence (including the empty one), and ?,
/// which matches any single character. Note this query can be slow, as it
/// needs to iterate over many terms. In order to prevent extremely slow WildcardQueries,
/// a Wildcard term should not start with one of the wildcards * or
/// ?.
///
/// This query uses the
///
/// rewrite method.
///
///
///
///
[Serializable]
public class WildcardQuery : MultiTermQuery
{
private readonly bool _termContainsWildcard;
private readonly bool _termIsPrefix;
protected internal Term term;
public WildcardQuery(Term term)
{
this.term = term;
string text = term.Text;
_termContainsWildcard = (term.Text.IndexOf('*') != -1)
|| (term.Text.IndexOf('?') != -1);
_termIsPrefix = _termContainsWildcard
&& (text.IndexOf('?') == -1)
&& (text.IndexOf('*') == text.Length - 1);
}
protected internal override FilteredTermEnum GetEnum(IndexReader reader)
{
if (_termContainsWildcard)
{
return new WildcardTermEnum(reader, Term);
}
else
{
return new SingleTermEnum(reader, Term);
}
}
/// Returns the pattern term.
public Term Term
{
get { return term; }
}
public override Query Rewrite(IndexReader reader)
{
if (_termIsPrefix)
{
MultiTermQuery rewritten =
new PrefixQuery(term.CreateTerm(term.Text.Substring(0, term.Text.IndexOf('*'))));
rewritten.Boost = Boost;
rewritten.RewriteMethod = RewriteMethod;
return rewritten;
}
else
{
return base.Rewrite(reader);
}
}
/// Prints a user-readable version of this query.
public override System.String ToString(System.String field)
{
System.Text.StringBuilder buffer = new System.Text.StringBuilder();
if (!term.Field.Equals(field))
{
buffer.Append(term.Field);
buffer.Append(":");
}
buffer.Append(term.Text);
buffer.Append(ToStringUtils.Boost(Boost));
return buffer.ToString();
}
//@Override
public override int GetHashCode()
{
int prime = 31;
int result = base.GetHashCode();
result = prime * result + ((term == null)?0:term.GetHashCode());
return result;
}
//@Override
public override bool Equals(System.Object obj)
{
if (this == obj)
return true;
if (!base.Equals(obj))
return false;
if (GetType() != obj.GetType())
return false;
WildcardQuery other = (WildcardQuery) obj;
if (term == null)
{
if (other.term != null)
return false;
}
else if (!term.Equals(other.term))
return false;
return true;
}
}
}