Java PriorityQueue实现类lucene段合并

Java自带 PriorityQueue实现类lucene段合并，当需要自定义比较器的时候没有Lucene自实现的PriorityQueue好用.

 

1.封装类型 Book

package com.taobao.terminator.allen.LuceneTest;public class Book { private String name; private int id; private String owner; public Book (String name, String owner, int id) { this.name = name; this.owner = owner; this.id = id; } public String getOwner() {return owner;}public void setOwner(String owner) {this.owner = owner;} public String getName() {return name;}public void setName(String name) {this.name = name;}public int getId() {return id;}public void setId(int id) {this.id = id;}} 

 

2.比较器

import java.util.Comparator;import java.util.List;public class AllenComparator implements Comparator<List<Book>>{/** * 比较二个List的大小，以第一个元素的姓名值作比较 */public int compare(List<Book> o1, List<Book> o2) {return o1.get(0).getName().compareTo(o2.get(0).getName());}} 

 

 

3.PriorityQueue代码测试

import java.util.ArrayList;import java.util.Comparator;import java.util.List;import java.util.PriorityQueue;public class PriorityQueueTest {private List<Book> list1 ;private List<Book> list2 ;private List<Book> list3 ;public PriorityQueueTest (){this.list1 = new ArrayList<Book>();this.list2 = new ArrayList<Book>();this.list3 = new ArrayList<Book>();initData(list1, list2, list3);}private void initData(List<Book> list1, List<Book> list2, List<Book> list3) {generatorData(list1, "owner-1", 1);generatorData(list2, "owner-2", 2);generatorData(list3, "owner-3", 3);}/** * 生成List数据集 * @param list * @param i 相同数据重复次数 */private void generatorData(List<Book> list, String owner, int i) {int k = 0;while(k < i) {list.add(new Book("name-ini" + i, owner, k));k++;}}public static void main(String[] args) {PriorityQueueTest test = new PriorityQueueTest();Comparator<List<Book>> comparator = new AllenComparator();PriorityQueue<List<Book>> queue = new PriorityQueue<List<Book>>(3, comparator); PriorityQueue<List<Book>> matchQueue = new PriorityQueue<List<Book>>(3, comparator); queue.add(test.list1);queue.add(test.list2);queue.add(test.list3);while(!queue.isEmpty()) {List<Book> list = queue.poll();matchQueue.add(list);System.out.println("name--->" + list.get(0).getName() + " owner--->" + list.get(0).getOwner() + " id--->" + list.get(0).getId());List<Book> cList = queue.peek();while (cList != null && list.get(0).getName().equals(cList.get(0).getName())) {List<Book> nlist = queue.poll();matchQueue.add(nlist);System.out.println("name--->" + nlist.get(0).getName() + " owner--->" + nlist.get(0).getOwner() + " id--->" + nlist.get(0).getId());cList = queue.peek();}//matchingQueuewhile(matchQueue.size() > 0) {List<Book> mList = matchQueue.poll();mList.remove(0);if(mList.size() > 0) {queue.add(mList);}}}}} 

 

4.结果输出

 

 name--->name-ini1 owner--->owner-1 id--->0name--->name-ini2 owner--->owner-2 id--->0name--->name-ini2 owner--->owner-2 id--->1name--->name-ini3 owner--->owner-3 id--->0name--->name-ini3 owner--->owner-3 id--->1name--->name-ini3 owner--->owner-3 id--->2