今天就跟大家聊聊有关如何使用List对象实现去重,可能很多人都不太了解,为了让大家更加了解,小编给大家总结了以下内容,希望大家根据这篇文章可以有所收获。
1、List<Object>去重
People类
public class People {
private int id;
private String name;
private Date createDate;
public int getId() {
return id;
}
public void setId(int id) {
this.id = id;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public Date getCreateDate() {
return createDate;
}
public void setCreateDate(Date createDate) {
this.createDate = createDate;
}
}
main方法
public static void main(String[] args) throws Exception{
List<People> list = new ArrayList<People>();
People p1 = new People();
p1.setId(1);
p1.setName("赵");
list.add(p1);
People p2 = new People();
p2.setId(2);
p2.setName("钱");
list.add(p2);
People p3 = new People();
p3.setId(3);
p3.setName("孙");
list.add(p3);
People p4 = new People();
p4.setId(4);
p4.setName("李");
list.add(p4);
People p5 = new People();
p5.setId(5);
p5.setName("周");
list.add(p5);
list.add(p1);
for(People p : list){
System.out.println(p);
}
System.out.println("==========================");
Set<People> set = new HashSet<People>(list);
list.clear();
list.addAll(new ArrayList<People>(set));
for(People p : list){
System.out.println(p);
}
}
2、List<Object>按照日期字段排序
自定义Comparator
public class MyComparator implements Comparator<People> {
@Override
public int compare(People p1, People p2) {
return p1.getCreateDate().compareTo(p2.getCreateDate());
}
}
main方法
public static void main(String[] args) throws Exception{
List<People> list = new ArrayList<People>();
People p1 = new People();
p1.setId(1);
p1.setName("赵");
p1.setCreateDate(new Date(new Date().getTime() + 1000));
list.add(p1);
People p2 = new People();
p2.setId(2);
p2.setName("钱");
p2.setCreateDate(new Date(new Date().getTime() + 8000));
list.add(p2);
People p3 = new People();
p3.setId(3);
p3.setName("孙");
p3.setCreateDate(new Date(new Date().getTime() + 7000));
list.add(p3);
People p4 = new People();
p4.setId(4);
p4.setName("李");
p4.setCreateDate(new Date(new Date().getTime() + 5000));
list.add(p4);
People p5 = new People();
p5.setId(5);
p5.setName("周");
p5.setCreateDate(new Date(new Date().getTime() + 6000));
list.add(p5);
for(People p : list){
System.out.println(p.getId());
}
//1,2,3,4,5
System.out.println("=======================");
Collections.sort(list, new MyComparator());
//1,4,5,3,2
for(People p : list){
System.out.println(p.getId());
}
}
看完上述内容,你们对如何使用List对象实现去重有进一步的了解吗?如果还想了解更多知识或者相关内容,请关注亿速云行业资讯频道,感谢大家的支持。
亿速云「云服务器」,即开即用、新一代英特尔至强铂金CPU、三副本存储NVMe SSD云盘,价格低至29元/月。点击查看>>
免责声明:本站发布的内容(图片、视频和文字)以原创、转载和分享为主,文章观点不代表本网站立场,如果涉及侵权请联系站长邮箱:is@yisu.com进行举报,并提供相关证据,一经查实,将立刻删除涉嫌侵权内容。