content: package org.apache.lucene.search;
  
  /**
   * 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.
   */
  
  import org.apache.lucene.index.IndexReader;
  import org.apache.lucene.index.Term;
  import org.apache.lucene.util.ToStringUtils;
  
  import java.io.IOException;
  
  /** Implements the wildcard search query. Supported wildcards are <code>*</code>, which
   * matches any character sequence (including the empty one), and <code>?</code>,
   * 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 <code>*</code> or
   * <code>?</code>.
   * 
   * <p>This query uses the {@link
   * MultiTermQuery#CONSTANT_SCORE_AUTO_REWRITE_DEFAULT}
   * rewrite method.
   *
   * @see WildcardTermEnum */
  public class WildcardQuery extends MultiTermQuery {
    private boolean termContainsWildcard;
    private boolean termIsPrefix;
    protected Term term;
      
    public WildcardQuery(Term term) {
      this.term = term;
      String text = term.text();
      this.termContainsWildcard = (text.indexOf('*') != -1)
          || (text.indexOf('?') != -1);
      this.termIsPrefix = termContainsWildcard 
          && (text.indexOf('?') == -1) 
          && (text.indexOf('*') == text.length() - 1);
    }
  
    @Override
    protected FilteredTermEnum getEnum(IndexReader reader) throws IOException {
      if (termIsPrefix) {
        return new PrefixTermEnum(reader, term.createTerm(term.text()
            .substring(0, term.text().indexOf('*')))); 
      } else if (termContainsWildcard) {
        return new WildcardTermEnum(reader, getTerm());
      } else {
        return new SingleTermEnum(reader, getTerm());
      }
    }
    
    /**
     * Returns the pattern term.
     */
    public Term getTerm() {
      return term;
    }
    
    /** Prints a user-readable version of this query. */
    @Override
    public String toString(String field) {
      StringBuilder buffer = new StringBuilder();
      if (!term.field().equals(field)) {
        buffer.append(term.field());
        buffer.append(":");
      }
      buffer.append(term.text());
      buffer.append(ToStringUtils.boost(getBoost()));
      return buffer.toString();
    }
  
    @Override
    public int hashCode() {
      final int prime = 31;
      int result = super.hashCode();
      result = prime * result + ((term == null) ? 0 : term.hashCode());
      return result;
    }
  
    @Override
    public boolean equals(Object obj) {
      if (this == obj)
        return true;
      if (!super.equals(obj))
        return false;
      if (getClass() != obj.getClass())
        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;
    }
  
  }
  