Lucene example source code file (KeepOnlyLastCommitDeletionPolicy.java)

This example Lucene source code file (KeepOnlyLastCommitDeletionPolicy.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

indexcommit, indexcommit, indexdeletionpolicy, indexdeletionpolicy, keeponlylastcommitdeletionpolicy, keeponlylastcommitdeletionpolicy, util

The Lucene KeepOnlyLastCommitDeletionPolicy.java source code

package org.apache.lucene.index;

/**
 * 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.util.List;

/**
 * This {@link IndexDeletionPolicy} implementation that
 * keeps only the most recent commit and immediately removes
 * all prior commits after a new commit is done.  This is
 * the default deletion policy.
 */

public final class KeepOnlyLastCommitDeletionPolicy implements IndexDeletionPolicy {

  /**
   * Deletes all commits except the most recent one.
   */
  public void onInit(List<? extends IndexCommit> commits) {
    // Note that commits.size() should normally be 1:
    onCommit(commits);
  }

  /**
   * Deletes all commits except the most recent one.
   */
  public void onCommit(List<? extends IndexCommit> commits) {
    // Note that commits.size() should normally be 2 (if not
    // called by onInit above):
    int size = commits.size();
    for(int i=0;i<size-1;i++) {
      commits.get(i).delete();
    }
  }
}