Lucene example source code file (RemoteCachingWrapperFilter.java)

This example Lucene source code file (RemoteCachingWrapperFilter.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

deprecated, deprecated, docidset, filter, filter, io, ioexception, ioexception, override, remotecachingwrapperfilter, remotecachingwrapperfilter

The Lucene RemoteCachingWrapperFilter.java source code

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 java.io.IOException;

import org.apache.lucene.index.IndexReader;

/**
 * Provides caching of {@link org.apache.lucene.search.Filter}s themselves on the remote end of an RMI connection.
 * The cache is keyed on Filter's hashCode(), so if it sees the same filter twice
 * it will reuse the original version.
 * <p/>
 * NOTE: This does NOT cache the Filter bits, but rather the Filter itself.
 * Thus, this works hand-in-hand with {@link org.apache.lucene.search.CachingWrapperFilter} to keep both
 * file Filter cache and the Filter bits on the remote end, close to the searcher.
 * <p/>
 * Usage:
 * <p/>
 * To cache a result you must do something like 
 * RemoteCachingWrapperFilter f = new RemoteCachingWrapperFilter(new CachingWrapperFilter(myFilter));
 * <p/>
 *
 * @deprecated This package (all of contrib/remote) will be
 * removed in 4.0.
 */
@Deprecated
public class RemoteCachingWrapperFilter extends Filter {
  protected Filter filter;

  public RemoteCachingWrapperFilter(Filter filter) {
    this.filter = filter;
  }
  
  /**
   * Uses the {@link org.apache.lucene.search.FilterManager} to keep the cache for a filter on the 
   * searcher side of a remote connection.
   * @param reader the index reader for the Filter
   * @return the DocIdSet
   */
  @Override
  public DocIdSet getDocIdSet(IndexReader reader) throws IOException {
    Filter cachedFilter = FilterManager.getInstance().getFilter(filter);
    return cachedFilter.getDocIdSet(reader);
  }
}