package dev.elaine.basics;

public final class GreetingService {
    public String greet(String name) {
        if (name == null || name.isBlank()) {
            throw new IllegalArgumentException("姓名不能为空");
        }
        return "你好，" + name + "！";
    }

    public static void main(String[] args) {
        System.out.println(new GreetingService().greet("Java 学习者"));
    }
}