从10000000个元素里面找出最大的前100个

? ? ? ? ? ?如题，从最大的10000000个元素里面找出最大的前100个，下面是我的代码实现：

? ? ? ? ?

import java.util.Comparator;
import java.util.PriorityQueue;
import java.util.Random;
import java.util.logging.Logger;


public class FixSizedPriorityQueue<E extends Comparable> {
	private final static Logger logger = Logger.getLogger(FixSizedPriorityQueue.class.getName());
	
	private PriorityQueue<E> queue;
	private int maxSize; // 堆的最大容量

	public FixSizedPriorityQueue(int maxSize) {
		if (maxSize <= 0)
			throw new IllegalArgumentException();
		this.maxSize = maxSize;
		this.queue = new PriorityQueue(maxSize, new Comparator<E>() {
			@Override
			public int compare(E o1, E o2) {
				return o1.compareTo(o2);
			}
		});
	}

	public void add(E e) {
		if (queue.size() < maxSize) { 
			queue.add(e);
		} else { 
			E peek = queue.peek();
			if (e.compareTo(peek) > 0) {
				queue.poll();
				queue.add(e);
			}
		}
	}
	
	public PriorityQueue<E> getQueue(){
		return queue;
	}

	
	public static void main(String[] args) {
		final int length = 10000000;
		final int maxSize = 100;
		
		FixSizedPriorityQueue<Integer> fixedQueue = new FixSizedPriorityQueue<Integer>(maxSize);
		Random random = new Random();
		for(int i =1; i < length; i++){
			fixedQueue.add(random.nextInt(i));
		}
		
		PriorityQueue<Integer> queue = fixedQueue.getQueue();
		Object obj = queue.poll();
		while(obj != null){
			logger.info(obj.toString());
			obj = queue.poll();
		}
	}
}

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从10000000个元素里面找出最大的前100个

原文：http://asialee.iteye.com/blog/2169455