需求： 需要对List中的每个User按照birthday顺序排序，时间由小到大排列。
package com.tree.ztree_demo.orderby; import java.text.SimpleDateFormat; import java.util.*; public class ListSort { public static class UserBean { private String id; private String birthday; public String getId() { return id; } public void setId(String id) { this.id = id; } public String getBirthday() { return birthday; } public void setBirthday(String birthday) { this.birthday = birthday; } } public static void main(String[] args) { List<UserBean> list = new ArrayList<UserBean>(); UserListGenerate(list); System.out.println("********排序前*******"); for (UserBean user : list) { System.out.println(user.getBirthday()); } ListSort(list); System.out.println("******排序后*****"); for (UserBean user : list) { System.out.println(user.getBirthday()); } } private static void UserListGenerate(List<UserBean> list) { UserBean user1 = new UserBean(); UserBean user2 = new UserBean(); UserBean user3 = new UserBean(); user1.setId("zhagnsan"); user1.setBirthday("1980/11/01"); user2.setId("lisi"); user2.setBirthday("1981/12/01"); user3.setId("wangwu"); user3.setBirthday("1980/12/01"); list.add(user1); list.add(user2); list.add(user3); } private static void ListSort(List<UserBean> list) { Collections.sort(list,new Comparator<UserBean>() { @Override public int compare(UserBean o1,UserBean o2) { SimpleDateFormat format = new SimpleDateFormat("yyyy/MM/dd"); try { Date dt1 = format.parse(o1.getBirthday()); Date dt2 = format.parse(o2.getBirthday()); 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; } }); } }
