在Java中如何使用Collections工具类进行集合排序_Collections排序技巧

List<String> names = Arrays.asList("Alice", "Bob", "Charlie");
Collections.sort(names);
System.out.println(names); // 输出: [Alice, Bob, Charlie]

List<String> words = Arrays.asList("Java", "is", "awesome");
Collections.sort(words, (a, b) -> a.length() - b.length());
System.out.println(words); // 输出: [is, Java, awesome]

Collections.sort(words, Comparator.comparing(String::length));

class Student {
    String name;
    int age;
    // 构造方法、getter等省略
}

List<Student> students = new ArrayList<>();
students.add(new Student("Alice", 22));
students.add(new Student("Bob", 20));
<p>Collections.sort(students, (s1, s2) -> s1.age - s2.age);
// 或使用 Comparator.comparing(Students::getAge)</p>

List<Integer> numbers = Arrays.asList(3, 1, 4, 1, 5);
Collections.sort(numbers, Comparator.reverseOrder());
System.out.println(numbers); // 输出: [5, 4, 3, 1, 1]

Comparator<String> byLength = Comparator.comparing(String::length);
Collections.sort(words, byLength.reversed());