集合去重

1、LinkedHashSet去重

List<String> list = new ArrayList<>();

list.add("111");
list.add("22");
list.add("111");
list.add("33");
list.add("111");
List<String> newPhoneList = new ArrayList<String>(new LinkedHashSet<>(list));//LinkedHashSet集合去重

2、stream去重

 //添加信息
    List<PenBean> penBeanList = new ArrayList<PenBean>();
    penBeanList.add(new PenBean("铅笔","black"));
    penBeanList.add(new PenBean("铅笔","white"));
    penBeanList.add(new PenBean("铅笔","black"));
    penBeanList.add(new PenBean("中性笔","white"));
    penBeanList.add(new PenBean("中性笔","white"));
 
    //使用java8新特性stream进行List去重
    List<PenBean> newPenBeanList = penBeanList.stream().distinct().collect(Collectors.toList());

3、Hashset去重

 //添加信息
    List<PenBean> penBeanList = new ArrayList<PenBean>();
    penBeanList.add(new PenBean("铅笔","black"));
    penBeanList.add(new PenBean("铅笔","white"));
    penBeanList.add(new PenBean("铅笔","black"));
    penBeanList.add(new PenBean("中性笔","white"));
    penBeanList.add(new PenBean("中性笔","white"));
 
    //新数据
    List<PenBean> newPenBeanList = new ArrayList<PenBean>();
    //set去重
    HashSet<PenBean> set = new HashSet<>(penBeanList);
    newPenBeanList.addAll(set);