package com.liying.banana.user;

import java.util.ArrayList;

import java.util.Comparator;

import java.util.List;

import java.util.Set;

import java.util.TreeSet;

import com.liying.banana.order.vo.OrderVO;

/**

 * List集合中的对象按照某个字段去重实现

 *

 * @author jqlin

 *

 */

public class DuplicateOrderTest {

    public static void main(String[] args) {

        List<OrderVO> orderList = new ArrayList<OrderVO>();

        OrderVO orderVO = new OrderVO();

        orderVO.setOrderNo("11");

        orderVO.setUserId("aa");

        orderList.add(orderVO);

        orderVO = new OrderVO();

        orderVO.setOrderNo("22");

        orderVO.setUserId("bb");

        orderList.add(orderVO);

        orderVO = new OrderVO();

        orderVO.setOrderNo("33");

        orderVO.setUserId("aa");

        orderList.add(orderVO);

        List<OrderVO> dataList = removeDuplicateOrder(orderList);

        for(OrderVO data : dataList){

            System.out.println(data.getOrderNo() + ":" + data.getUserId());

        }

    }

    /**

     * 去重

     *

     * @param orderList

     * @return

     * @author jqlin

     */

    private static List<OrderVO> removeDuplicateOrder(List<OrderVO> orderList) {

        Set<OrderVO> set = new TreeSet<OrderVO>(new Comparator<OrderVO>() {

            @Override

            public int compare(OrderVO a, OrderVO b) {

                // 字符串则按照asicc码升序排列

                return a.getUserId().compareTo(b.getUserId());

            }

        });

        set.addAll(orderList);

        return new ArrayList<OrderVO>(set);

    }

}

11:aa

22:bb