如何在java中对列表中的最早时间戳进行排序?
预期结果显示第0个索引中最早的上午11:45如何在java中对列表中的最早时间戳进行排序?,java,list,time,java-time,datetime-parsing,Java,List,Time,Java Time,Datetime Parsing,预期结果显示第0个索引中最早的上午11:45 我已尝试将上述列表转换为整数,当特定时间(12:35 PM)中存在唯一时间(AM/PM)时,我可以对其进行排序,但当特定时间(12:35 PM,12:05 PM)中存在多个时间戳时,我无法进行排序。一个问题是,类似4 PM的时间将在列表中显示为4.0,因此,前面的时间类似于11:45am(显示为11.45)。我建议看一看java.util.Date和friends之类的类,找到一个函数,它可以将这些时间转换为另一种格式,如午夜后的秒数或24小时表示法
我已尝试将上述列表转换为整数,当特定时间(12:35 PM)中存在唯一时间(AM/PM)时,我可以对其进行排序,但当特定时间(12:35 PM,12:05 PM)中存在多个时间戳时,我无法进行排序。一个问题是,类似
4 PM
的时间将在列表中显示为4.0,因此,前面的时间类似于11:45am
(显示为11.45)。我建议看一看java.util.Date和friends之类的类,找到一个函数,它可以将这些时间转换为另一种格式,如午夜后的秒数或24小时表示法,然后按这种格式排序。最简单的解决方案之一是对下面的代码进行修改:
- 分拣前将12:mm AM/PM转换为00:mm AM/PM
- 将hh:mm AM转换为hh.mm,将hh:mm转换为(hh+12).mm
- 对列表排序
- 将hh.mm转换为hh:mm AM/PM
结果是:my Timestamps = [12:40 PM, 4:00 PM, 7:20 PM, 10:40 PM, 12:00 PM, 3:25 PM, 6:50 PM, 10:15 PM, 6:35 PM, 9:50 PM, 12:20 PM, 3:45 PM, 7:15 PM, 10:40 PM, 11:45 AM, 3:10 PM, 6:35 PM, 10:25 PM, 12:50 PM, 4:10 PM, 7:30 PM, 10:40 PM]
更高效的代码将在稍后的编辑中出现。java.time 我建议您使用* 更新:发布带有非lamda表达式的代码以进行排序(由OP在评论部分请求)String a = "9:50 PM,12:25 PM,3:55 PM,10:15 PM,1:15 PM,1:00 AM, 12:25 AM, 10:13 AM";
从了解有关现代日期时间API的更多信息import java.time.LocalTime; 导入java.time.format.DateTimeFormatter; 导入java.time.format.DateTimeFormatterBuilder; 导入java.util.array; 导入java.util.Collections; 导入java.util.Comparator; 导入java.util.List; 导入java.util.Locale; 公共班机{ 公共静态void main(字符串参数[]){ 字符串[]timeStrArr={“12:40 PM”,“4:00 PM”,“7:20 PM”,“10:40 PM”,“12:00 PM”,“3:25 PM”,“6:50 PM”, “晚上10:15”,“下午6:35”,“晚上9:50”,“下午12:20”,“下午3:45”,“晚上7:15”,“晚上10:40”,“上午11:45”,“下午3:10”, ‘下午六时三十五分’、‘十时二十五分’、‘十二时五十分’、‘四时十分’、‘七时三十分’、‘十时四十分’; List timeList=Arrays.asList(timeStrArr); DateTimeFormatter timeFormat=新的DateTimeFormatterBuilder() .parseCase不敏感() .追加模式(“h:m a”) .toFormatter(Locale.ENGLISH); Collections.sort(timeList,newcomparator(){ 公共整数比较(字符串s1、字符串s2){ 返回LocalTime.parse(s1,timeFormat.compareTo(LocalTime.parse(s2,timeFormat)); } }); System.out.println(时间列表); System.out.println(“列表中的最早时间:“+timeList.get(0)); } }
*无论出于何种原因,如果您必须坚持使用Java6或Java7,您可以使用哪个backport将大部分Java.time功能移植到Java6&7。如果您正在为Android项目工作,并且您的Android API级别仍然不符合Java-8,请检查并确认。
尝试使用此代码。它很紧凑。使用Java8定义一个比较器,该比较器将完成排序时间的工作。 `
` 用于输入String arg[]=a.split(“,”); List
al=newarraylist (); al=数组.asList(arg); Collections.sort(al,(x,y)->{ int结果; 字符串[]splitx=x.trim().split(\\s+); 字符串[]splity=y.trim().split(\\s+); if(splitx[1].equals(“AM”)和&splity[1].equals(“PM”)){ 结果=-1; }else if(splitx[1].equals(“PM”)和&splity[1].equals(“AM”)){ 结果=1; }否则{ 结果=x。与(y)相比; } 返回结果; }); 系统输出打印项次(al);
输出将为:String a=“12:40 PM、4:00 PM、7:20 AM、10:40 PM、12:00 PM、3:25 AM、6:50 PM、10:15 PM、6:35 PM、9:50 PM、12:20 PM、3:45 PM、7:15 PM、10:40 PM、11:45 AM、3:10 PM、6:35 PM、10:25 PM、12:50 PM、4:10 PM、7:30 PM、10:40 PM”;
[11:45 AM,3:25 AM,7:20 AM,10:15 PM,10:25 PM,10:40 PM,10:40 PM,12:00 PM,12:20 PM,12:50 PM,3:10 PM,3:45 PM,4:00 PM,4:10 PM,6:35 PM,6:50 PM,7:30 PM,9:50 PM,12:40 PM]
希望它能解决您的问题。谢谢Arvind,您能给我解释一下第22行和第24行吗。如果您能将它改成非Lambda表达式,那就太好了,我对Lambda表达式不太熟悉。package collectionCollections; import java.util.ArrayList; import java.util.Arrays; import java.util.Collections; import java.util.Iterator; import java.util.List; import java.util.ListIterator; import java.util.concurrent.SynchronousQueue; public class TestCollections { public static void main(String[] args) { //String a = "9:50 PM,12:25 PM,3:55 PM,10:15 PM,1:15 PM"; String a = "9:50 PM,12:25 PM,3:55 PM,10:15 PM,1:15 PM,1:00 AM, 12:25 AM, 10:13 AM"; List<String> al2 = new ArrayList<>(); List<Float> al3 = new ArrayList<>(); List<String> al4 = new ArrayList<>(); // list of final results to display String arg[] = a.split(","); // System.out.println(arg); // Collections.sort(list); List<String> al = new ArrayList<String>(); al = Arrays.asList(arg); for (String s : al) { System.out.println(s); s = s.trim(); // remove leading and trailing spaces, otherwise the conversion to float will fail s = s.replace("12:", "00:"); // do not forget 12:00 is like 00:00 and 12:00 AM/PM is least than 1:00 AM/PM String[] t = s.split(" "); String ampm = t[1]; // extract AM/PM System.out.println("ampm "+ ampm ); if( ampm.toUpperCase().equals("PM")) { String h = t[0].split(":")[0]; // extract hours int hh = 12 + Integer.parseInt(h); // add 12 for PM t[0] = t[0].replace(h+":", hh+":"); } al2.add(t[0].replace(":", ".")); } System.out.println(al2); Iterator li = al2.iterator(); while (li.hasNext()) { String s = (String) li.next(); float no = Float.parseFloat(s); System.out.println(" s -> no : "+ s +" -> "+ no); al3.add(no); } Collections.sort(al3); ListIterator lit = al3.listIterator(); while (lit.hasNext()) { float f = (Float) lit.next(); int intno = (int) f; if(intno < 12 ) { int hour12 = intno == 0 ? 12 : intno; // replace 00:xx am by 12:xx am al4.add(hour12 +":"+ ((int)((f-intno)*100)) +" AM"); } else { al4.add((intno-12)+":"+ ((int)((f-intno)*100)) +" PM"); } } System.out.println(al4); } }
String a = "9:50 PM,12:25 PM,3:55 PM,10:15 PM,1:15 PM,1:00 AM, 12:25 AM, 10:13 AM";
[12:25 AM, 1:0 AM, 10:13 AM, 0:25 PM, 1:14 PM, 3:55 PM, 9:50 PM, 10:14 PM]
import java.time.LocalTime; import java.time.format.DateTimeFormatter; import java.time.format.DateTimeFormatterBuilder; import java.util.Arrays; import java.util.Collections; import java.util.List; import java.util.Locale; public class Main { public static void main(String args[]) { String[] timeStrArr = { "12:40 PM", "4:00 PM", "7:20 PM", "10:40 PM", "12:00 PM", "3:25 PM", "6:50 PM", "10:15 PM", "6:35 PM", "9:50 PM", "12:20 PM", "3:45 PM", "7:15 PM", "10:40 PM", "11:45 AM", "3:10 PM", "6:35 PM", "10:25 PM", "12:50 PM", "4:10 PM", "7:30 PM", "10:40 PM" }; List<String> timeList = Arrays.asList(timeStrArr); DateTimeFormatter timeFormat = new DateTimeFormatterBuilder() .parseCaseInsensitive() .appendPattern("h:m a") .toFormatter(Locale.ENGLISH); Collections.sort(timeList, (s1, s2) -> LocalTime.parse(s1, timeFormat).compareTo(LocalTime.parse(s2, timeFormat))); System.out.println(timeList); System.out.println("Earliest time in the list: " + timeList.get(0)); } }
[11:45 AM, 12:00 PM, 12:20 PM, 12:40 PM, 12:50 PM, 03:10 PM, 03:25 PM, 03:45 PM, 04:00 PM, 04:10 PM, 06:35 PM, 06:35 PM, 06:50 PM, 07:15 PM, 07:20 PM, 07:30 PM, 09:50 PM, 10:15 PM, 10:25 PM, 10:40 PM, 10:40 PM, 10:40 PM] Earliest time in the list: 11:45 AM
import java.time.LocalTime; import java.time.format.DateTimeFormatter; import java.time.format.DateTimeFormatterBuilder; import java.util.Arrays; import java.util.Collections; import java.util.Comparator; import java.util.List; import java.util.Locale; public class Main { public static void main(String args[]) { String[] timeStrArr = { "12:40 PM", "4:00 PM", "7:20 PM", "10:40 PM", "12:00 PM", "3:25 PM", "6:50 PM", "10:15 PM", "6:35 PM", "9:50 PM", "12:20 PM", "3:45 PM", "7:15 PM", "10:40 PM", "11:45 AM", "3:10 PM", "6:35 PM", "10:25 PM", "12:50 PM", "4:10 PM", "7:30 PM", "10:40 PM" }; List<String> timeList = Arrays.asList(timeStrArr); DateTimeFormatter timeFormat = new DateTimeFormatterBuilder() .parseCaseInsensitive() .appendPattern("h:m a") .toFormatter(Locale.ENGLISH); Collections.sort(timeList, new Comparator<String>() { public int compare(String s1, String s2) { return LocalTime.parse(s1, timeFormat).compareTo(LocalTime.parse(s2, timeFormat)); } }); System.out.println(timeList); System.out.println("Earliest time in the list: " + timeList.get(0)); } }
String arg[] = a.split(","); List < String > al = new ArrayList < String > (); al = Arrays.asList(arg); Collections.sort(al, (x,y)->{ int result ; String[] splitx = x.trim().split("\\s+"); String[] splity = y.trim().split("\\s+"); if(splitx[1].equals("AM") && splity[1].equals("PM")) { result= -1; }else if (splitx[1].equals("PM") && splity[1].equals("AM")) { result= 1; }else { result= x.compareTo(y); } return result; }); System.out.println(al);