如何创建为参数类型字段创建默认值的构造函数

public class MyClass {
    private String name;
    private int age;

    public MyClass(String name, int age) {
        if (name == null) {
            this.name = "Default Name";
        } else {
            this.name = name;
        }

        if (age <= 0) {
            this.age = 18;
        } else {
            this.age = age;
        }
    }

    // 其他方法和逻辑...

    public static void main(String[] args) {
        MyClass obj1 = new MyClass(null, -1);
        System.out.println(obj1.getName());  // 输出：Default Name
        System.out.println(obj1.getAge());   // 输出：18

        MyClass obj2 = new MyClass("John", 25);
        System.out.println(obj2.getName());  // 输出：John
        System.out.println(obj2.getAge());   // 输出：25
    }
}