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;
}
});
}
}