Hello everyone, I am a pig arched by cabbage.
Background: The comments of the article show it, the first reply is ranked first, and the later comment shows the
effect: 
code:
//对List<Reply> 按照回帖时间进行升序排序
public void ListSort(List<Reply> list) {
Collections.sort(list, new Comparator<Reply>() {
@Override
public int compare(Reply o1, Reply o2) {
SimpleDateFormat format = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
try {
Date dt1 = format.parse(o1.getReplyTime());
Date dt2 = format.parse(o2.getReplyTime());
if (dt1.getTime() > dt2.getTime()) {
return 1;
} else if (dt1.getTime() < dt2.getTime()) {
return -1;
} else {
return 0;
}
} catch (Exception e) {
e.printStackTrace();
}
return 0;
}
});
}
test:
public class ListSortTest {
public static void main(String[] args) {
try {
Reply reply1=new Reply(new Date());
Thread.sleep(1000);
Reply reply2=new Reply(new Date());
Thread.sleep(1000);
Reply reply3=new Reply(new Date());
Thread.sleep(1000);
Reply reply4=new Reply(new Date());
List<Reply> list=new LinkedList<>();
list.add(reply4);
list.add(reply2);
list.add(reply3);
list.add(reply1);
System.out.println("排序前");
for(Reply reply:list){
System.out.println(reply.getReplyTime());
}
System.out.println("排序后");
DateUtil du=new DateUtil();
du.ListSort(list);
for(Reply reply:list){
System.out.println(reply.getReplyTime());
}
} catch (InterruptedException e) {
e.printStackTrace();
}
}
}
result:
Only need to change the parameters when using
