Java多线程--两个线程同时对一个人的年龄进行增加和修改

public class Thread_A extends Thread {
    Human human;

    public Thread_A(String name, Human human) {
        super(name);
        this.human = human;
    }

    @Override
    public void run() {
        for (int i = 0; i < 100; i++) {
            human.setAge(human.getAge()+1);
            System.out.println(getName()+"线程实现Human的年龄+1，当前年龄："+human.getAge());
        }

    }
}

public class Thread_B extends Thread {
    Human human;

    public Thread_B(String name,Human human) {
        super(name);
        this.human = human;
    }

    @Override
    public void run() {
        for (int i = 0; i < 100; i++) {
            human.setAge(human.getAge()-1);
            System.out.println(getName()+"线程实现Human的年龄-1，当前年龄："+human.getAge());
        }
    }
}

public class TestThread {
    public static void main(String[] args) {
        Human human = new Human("张三", 10);
        Thread t1 = new Thread(new Thread_A("A",human));
        Thread t2 = new Thread(new Thread_B("B",human));
        t1.start();
        t2.start();
    }
}

@SuppressWarnings("all")
public class Human {
    private String name;
    private int age;

    public Human() {
    }

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

    public int getAge() {
        return age;
    }

    public synchronized void setAge(int age) {
        if (age>0){
            this.age = age;
        }else {
            this.age = 0;
        }
    }

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