lucene PriorityQueue 优先队列

导读：
　　PriorityQueue 实现一优先队列框架，实例非常简单，只需实现lessThan(Object a, Object b)方法即可，通过该方法可以控制大优先或小优先。
　　package org.apache.lucene.search;
　　/**
　　* Copyright 2004 The Apache Software Foundation
　　*
　　* Licensed 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.util.PriorityQueue;
　　final class HitQueue extends PriorityQueue {
　　HitQueue(int size) {
　　initialize(size);
　　}
　　/**
　　*
　　* Annotator:yezheng
　　*/
　　protected final boolean lessThan(Object a, Object b) {
　　ScoreDoc hitA = (ScoreDoc)a;
　　ScoreDoc hitB = (ScoreDoc)b;
　　if (hitA.score == hitB.score)
　　return hitA.doc > hitB.doc; // 如果分数相同则按索引先后顺序排序
　　else
　　return hitA.score 　　}
　　}

本文转自
http://blog.lough.com.cn/post/235/