Record类与数据封装：什么是Record？如何在JDK 16+中减少样板代码？

public class Person {
    private final String name;
    private final int age;

    public Person(String name, int age) {
        this.name = name;
        this.age = age;
    }

    public String getName() { return name; }
    public int getAge() { return age; }

    @Override
    public boolean equals(Object o) {
        if (this == o) return true;
        if (o == null || getClass() != o.getClass()) return false;
        Person person = (Person) o;
        return age == person.age && Objects.equals(name, person.name);
    }

    @Override
    public int hashCode() {
        return Objects.hash(name, age);
    }

    @Override
    public String toString() {
        return "Person{name='" + name + "', age=" + age + "}";
    }
}

public record Person(String name, int age) {}

public record Person(String name, int age) {}

public class Main {
    public static void main(String[] args) {
        Person person1 = new Person("猫头虎", 25);
        Person person2 = new Person("猫头虎", 25);

        System.out.println(person1.name());  // 调用getter方法，输出：猫头虎
        System.out.println(person1);         // 自动生成toString()，输出：Person[name=猫头虎, age=25]
        System.out.println(person1.equals(person2)); // 比较对象，输出：true
    }
}

public record Person(String name, int age) {
    // 自定义构造方法，验证数据
    public Person {
        if (age < 0) {
            throw new IllegalArgumentException("年龄不能小于0");
        }
    }
}

Person person = new Person("猫头虎", 25);
// person.name = "新名字"; // 编译错误，字段是final的，无法修改。

public record Pair<K, V>(K key, V value) {}

public class Main {
    public static void main(String[] args) {
        Pair<String, Integer> pair = new Pair<>("年龄", 25);
        System.out.println(pair); // 输出：Pair[key=年龄, value=25]
    }
}