Lucene example source code file (SpanNotQuery.java)

This example Lucene source code file (SpanNotQuery.java) is included in the DevDaily.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" ^TM.

Java - Lucene tags/keywords

arraylist, indexreader, io, ioexception, ioexception, object, override, override, spannotquery, spannotquery, spanquery, spanquery, spans, string, stringbuilder, util

The Lucene SpanNotQuery.java source code

package org.apache.lucene.search.spans;

/**
 * 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.search.Query;
import org.apache.lucene.util.ToStringUtils;

import java.io.IOException;
import java.util.ArrayList;
import java.util.Collection;
import java.util.Set;

/** Removes matches which overlap with another SpanQuery. */
public class SpanNotQuery extends SpanQuery implements Cloneable {
  private SpanQuery include;
  private SpanQuery exclude;

  /** Construct a SpanNotQuery matching spans from <code>include which
   * have no overlap with spans from <code>exclude.*/
  public SpanNotQuery(SpanQuery include, SpanQuery exclude) {
    this.include = include;
    this.exclude = exclude;

    if (!include.getField().equals(exclude.getField()))
      throw new IllegalArgumentException("Clauses must have same field.");
  }

  /** Return the SpanQuery whose matches are filtered. */
  public SpanQuery getInclude() { return include; }

  /** Return the SpanQuery whose matches must not overlap those returned. */
  public SpanQuery getExclude() { return exclude; }

  @Override
  public String getField() { return include.getField(); }

  @Override
  public void extractTerms(Set<Term> terms) { include.extractTerms(terms); }

  @Override
  public String toString(String field) {
    StringBuilder buffer = new StringBuilder();
    buffer.append("spanNot(");
    buffer.append(include.toString(field));
    buffer.append(", ");
    buffer.append(exclude.toString(field));
    buffer.append(")");
    buffer.append(ToStringUtils.boost(getBoost()));
    return buffer.toString();
  }

  @Override
  public Object clone() {
    SpanNotQuery spanNotQuery = new SpanNotQuery((SpanQuery)include.clone(),(SpanQuery) exclude.clone());
    spanNotQuery.setBoost(getBoost());
    return  spanNotQuery;
  }

  @Override
  public Spans getSpans(final IndexReader reader) throws IOException {
    return new Spans() {
        private Spans includeSpans = include.getSpans(reader);
        private boolean moreInclude = true;

        private Spans excludeSpans = exclude.getSpans(reader);
        private boolean moreExclude = excludeSpans.next();

        @Override
        public boolean next() throws IOException {
          if (moreInclude)                        // move to next include
            moreInclude = includeSpans.next();

          while (moreInclude && moreExclude) {

            if (includeSpans.doc() > excludeSpans.doc()) // skip exclude
              moreExclude = excludeSpans.skipTo(includeSpans.doc());

            while (moreExclude                    // while exclude is before
                   && includeSpans.doc() == excludeSpans.doc()
                   && excludeSpans.end() <= includeSpans.start()) {
              moreExclude = excludeSpans.next();  // increment exclude
            }

            if (!moreExclude                      // if no intersection
                || includeSpans.doc() != excludeSpans.doc()
                || includeSpans.end() <= excludeSpans.start())
              break;                              // we found a match

            moreInclude = includeSpans.next();    // intersected: keep scanning
          }
          return moreInclude;
        }

        @Override
        public boolean skipTo(int target) throws IOException {
          if (moreInclude)                        // skip include
            moreInclude = includeSpans.skipTo(target);

          if (!moreInclude)
            return false;

          if (moreExclude                         // skip exclude
              && includeSpans.doc() > excludeSpans.doc())
            moreExclude = excludeSpans.skipTo(includeSpans.doc());

          while (moreExclude                      // while exclude is before
                 && includeSpans.doc() == excludeSpans.doc()
                 && excludeSpans.end() <= includeSpans.start()) {
            moreExclude = excludeSpans.next();    // increment exclude
          }

          if (!moreExclude                      // if no intersection
                || includeSpans.doc() != excludeSpans.doc()
                || includeSpans.end() <= excludeSpans.start())
            return true;                          // we found a match

          return next();                          // scan to next match
        }

        @Override
        public int doc() { return includeSpans.doc(); }
        @Override
        public int start() { return includeSpans.start(); }
        @Override
        public int end() { return includeSpans.end(); }

      // TODO: Remove warning after API has been finalized
      @Override
      public Collection<byte[]> getPayload() throws IOException {
        ArrayList<byte[]> result = null;
        if (includeSpans.isPayloadAvailable()) {
          result = new ArrayList<byte[]>(includeSpans.getPayload());
        }
        return result;
      }

      // TODO: Remove warning after API has been finalized
      @Override
      public boolean isPayloadAvailable() {
        return includeSpans.isPayloadAvailable();
      }

      @Override
      public String toString() {
          return "spans(" + SpanNotQuery.this.toString() + ")";
        }

      };
  }

  @Override
  public Query rewrite(IndexReader reader) throws IOException {
    SpanNotQuery clone = null;

    SpanQuery rewrittenInclude = (SpanQuery) include.rewrite(reader);
    if (rewrittenInclude != include) {
      clone = (SpanNotQuery) this.clone();
      clone.include = rewrittenInclude;
    }
    SpanQuery rewrittenExclude = (SpanQuery) exclude.rewrite(reader);
    if (rewrittenExclude != exclude) {
      if (clone == null) clone = (SpanNotQuery) this.clone();
      clone.exclude = rewrittenExclude;
    }

    if (clone != null) {
      return clone;                        // some clauses rewrote
    } else {
      return this;                         // no clauses rewrote
    }
  }

    /** Returns true iff <code>o is equal to this. */
  @Override
  public boolean equals(Object o) {
    if (this == o) return true;
    if (!(o instanceof SpanNotQuery)) return false;

    SpanNotQuery other = (SpanNotQuery)o;
    return this.include.equals(other.include)
            && this.exclude.equals(other.exclude)
            && this.getBoost() == other.getBoost();
  }

  @Override
  public int hashCode() {
    int h = include.hashCode();
    h = (h<<1) | (h >>> 31);  // rotate left
    h ^= exclude.hashCode();
    h = (h<<1) | (h >>> 31);  // rotate left
    h ^= Float.floatToRawIntBits(getBoost());
    return h;
  }

}