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); } }
执行结果:
11:aa
22:bb