从10000000个元素里面找出最大的前100个

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

Java代码  

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


public class FixSizedPriorityQueueextends Comparable> {
    private final static Logger logger = Logger.getLogger(FixSizedPriorityQueue.class.getName());

    private PriorityQueue 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() {
            @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 getQueue(){
        return queue;
    }


    public static void main(String[] args) {
        final int length = 10000000;
        final int maxSize = 100;

        FixSizedPriorityQueue fixedQueue = new FixSizedPriorityQueue(maxSize);
        Random random = new Random();
        for(int i =1; i < length; i++){
            fixedQueue.add(random.nextInt(i));
        }

        PriorityQueue queue = fixedQueue.getQueue();
        Object obj = queue.poll();
        while(obj != null){
            logger.info(obj.toString());
            obj = queue.poll();
        }
    }
}

转载于:https://blog.51cto.com/sun316737332/1607645