問題描述有一個list集合,包含name,可空。date非空。現(xiàn)在需要排序。需要name是null的排在前面,然后按照date排序問題出現(xiàn)的環(huán)境背景及自己嘗試過哪些方法list.sort();相關(guān)代碼//請把代碼文本粘貼到下方(請勿用圖片代替代碼)Listpeople=newArrayList();people.add(newPerson(1,null,sdf.parse("2019-09-2312:12:12")));people.add(newPerson(2,"1",sdf.parse("2019-09-2312:12:12")));people.add(newPerson(3,null,sdf.parse("2019-09-2412:12:12")));people.add(newPerson(4,"1",sdf.parse("2019-09-2412:12:12")));people.add(newPerson(5,null,sdf.parse("2019-09-1712:12:12")));people.add(newPerson(6,null,sdf.parse("2019-09-2412:12:12")));people.add(newPerson(8,null,sdf.parse("2019-09-2012:12:12")));people.add(newPerson(9,null,sdf.parse("2019-09-2312:12:12")));people.add(newPerson(10,"1",sdf.parse("2019-09-2012:12:12")));people.sort((t1,t2)->{if(t1.getName()==null&&t2.getName()!=null){return-1;}elseif(t2.getName()==null&&t1.getName()!=null){return-1;}elseif(Objects.equals(t1.getName(),t2.getName())){returnt1.getEntryDate().compareTo(t2.getEntryDate());}else{returnt1.getName().compareTo(t2.getName());}});System.out.println("SORT===========================");println(people);你期待的結(jié)果是什么?實際看到的錯誤信息又是什么?期望結(jié)果:Person[id=5,name=null,entryDate=2019-09-1712:12:12]Person[id=8,name=null,entryDate=2019-09-2012:12:12]Person[id=9,name=null,entryDate=2019-09-2312:12:12]Person[id=1,name=null,entryDate=2019-09-2312:12:12]Person[id=3,name=null,entryDate=2019-09-2412:12:12]Person[id=6,name=null,entryDate=2019-09-2412:12:12]Person[id=10,name=1,entryDate=2019-09-2012:12:12]Person[id=2,name=1,entryDate=2019-09-2312:12:12]Person[id=4,name=1,entryDate=2019-09-2412:12:12]輸出結(jié)果:SORT===========================Person[id=10,name=1,entryDate=2019-09-2012:12:12]Person[id=5,name=null,entryDate=2019-09-1712:12:12]Person[id=8,name=null,entryDate=2019-09-2012:12:12]Person[id=9,name=null,entryDate=2019-09-2312:12:12]Person[id=4,name=1,entryDate=2019-09-2412:12:12]Person[id=3,name=null,entryDate=2019-09-2412:12:12]Person[id=2,name=1,entryDate=2019-09-2312:12:12]Person[id=1,name=null,entryDate=2019-09-2312:12:12]Person[id=6,name=null,entryDate=2019-09-2412:12:12]
新手上路,java 根據(jù)兩個屬性排序大佬們有什么好的建議?
暮色呼如
2019-10-16 16:32:40