我是java新手，我正在尝试创建一个方法来更新对象的示例变量age。我正在编译代码，但是我没有看到年龄值的变化。此代码是赋值的一部分，因此我无法更改构造函数。我编写的更新年龄的方法（不起作用）如下所示。我的全部代码如下所示。我也很好奇是否有一种方法可以只更新/更改我的一个对象，但是在我这样做之前，我需要一种方法来处理这两个对象。如果您能帮助正确编写此方法，我们将不胜感激！

public void setnewAge(int age) {
    dogAge += 1;
    this.dogAge = dogAge;
}

下面是我的全部代码（包括我为更新age而编写的方法）。

public class Dog {
    //Instance Varibles
    private String dogName; 
    private int dogAge;
    private int dogWeight;

    //Two Contructors (One Completely Empty)
    public Dog() {
    }  

    public Dog(String name, int age, int weight){
        dogName = name;
        dogAge = age;
        dogWeight = weight;
    }   

    //Getters
    public String getName() { return dogName;}
    public int getAge() { return dogAge;}
    public int getWeight() { return dogWeight;}

    //Setters
    public void setName(String theName) { dogName = theName;}
    public void setAge(int theAge) {dogAge = theAge;}
    public void setWeight(int theWeight) {dogWeight = theWeight;}

    //to(String) method
    public String toString() {
        return  "The dogs's name is " + getName() + ", the dogs's age is " +
                getAge() + ", " + "\n" + "the dogs's weight is " + getWeight() + ".";
    }

    public void setnewAge(int age) {
        dogAge += 1;
        this.dogAge = dogAge;
    }       

    //Main Method
    public static void main(String[] args) {
        Dog poodle = new Dog("Bob", 5, 26);
        System.out.println(poodle);
        Dog lab = new Dog();
        lab.setName("Steve");
        lab.setAge(8);
        lab.setWeight(43);
        System.out.println(lab);
    }
}