Java PriorityQueue实现类lucene段合并

Lucene綱针

2011-04-23

关注关注

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();
}
//matchingQueue
while(matchQueue.size() > 0) {
List<Book> mList = matchQueue.poll();
mList.remove(0);
if(mList.size() > 0) {
queue.add(mList);
}
}
}
}
}