用于TreeMap的Java Spring比较器

import java.util.Comparator;
import java.util.Map;
import java.util.TreeMap;

public class TreeMapExample {
    public static void main(String[] args) {
        // 创建一个自定义比较器的TreeMap
        Map<String, Integer> treeMap = new TreeMap<>(new Comparator<String>() {
            @Override
            public int compare(String s1, String s2) {
                // 按字符串长度进行排序
                return Integer.compare(s1.length(), s2.length());
            }
        });

        // 添加元素
        treeMap.put("apple", 1);
        treeMap.put("banana", 2);
        treeMap.put("cherry", 3);
        treeMap.put("date", 4);

        // 输出结果
        for (Map.Entry<String, Integer> entry : treeMap.entrySet()) {
            System.out.println(entry.getKey() + " : " + entry.getValue());
        }
    }
}

Comparator<String> comparator = new Comparator<String>() {
    @Override
    public int compare(String s1, String s2) {
        if (s1 == null && s2 == null) return 0;
        if (s1 == null) return 1;
        if (s2 == null) return -1;
        return Integer.compare(s1.length(), s2.length());
    }
};