数据多项排序

干脆给它封装一个 Book 类 ~

import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.util.Arrays;
import java.util.Date;
import java.util.Scanner;

public class Main {
  public static void main(String[] args) {
    Scanner scanner = new Scanner(System.in);
    int n = scanner.nextInt();
    Book[] books = new Book[n];
    SimpleDateFormat dateFormat = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
    for (int i = 0; i < n; i++) {
      String[] row = scanner.next().split(",");
      try {
        String updateTime = row[3] + " " + scanner.next();
        Book book =
            new Book(
                Long.parseLong(row[0]),
                Integer.parseInt(row[1]),
                Integer.parseInt(row[2]),
                dateFormat.parse(updateTime));
        books[i] = book;
      } catch (ParseException e) {
        e.printStackTrace();
      }
    }
    scanner.close();
    // 升序排列。字段优先级：category > updateTime > words > id
    Arrays.sort(books, (book1, book2) -> {
      if (book1.getCategory() != book2.getCategory()) {
        return book1.getCategory() - book2.getCategory();
      }
      long update1 = book1.getUpdateTime().getTime(), update2 = book2.getUpdateTime().getTime();
      if (update1 != update2) {
        return (int) (update1 - update2);
      }
      if (book1.getWords() != book2.getWords()) {
        return book1.getWords() - book2.getWords();
      }
      return (int) (book1.getId() - book2.getId());
    });
    for (int i = 0; i < n; i++) {
      System.out.println(books[i].getId());
    }
  }
}

class Book {
  private final long id;
  private final int category;
  private final int words;
  private final Date updateTime;

  public Book(long id, int category, int words, Date updateTime) {
    this.id = id;
    this.category = category;
    this.words = words;
    this.updateTime = updateTime;
  }

  public long getId() {
    return this.id;
  }

  public int getCategory() {
    return this.category;
  }

  public int getWords() {
    return this.words;
  }

  public Date getUpdateTime() {
    return this.updateTime;
  }
}