如何在Java列表中对最早的时间戳进行排序？

下面的代码对您来说是最简单的解决方案，与您的代码几乎没有什么变化：

• 在排序之前将12：mm AM / PM转换为00：mm AM / PM
• 将hh：mm AM转换为hh.mm，并将hh：mm转换为（hh + 12）.mm
• 排序列表

• 将hh.mm转换为hh：mm AM / PM

  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);
  }
  }
  

与清单

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";

结果是：

[12:25 AM, 1:0 AM, 10:13 AM, 0:25 PM, 1:14 PM, 3:55 PM, 9:50 PM, 10:14 PM]

以后的编辑中将提供更有效的代码。