如何重写一个对象的if？

public class MyClass {
    private int value;
    
    public MyClass(int value) {
        this.value = value;
    }
    
    @Override
    public String toString() {
        if (value > 0) {
            return "Positive";
        } else if (value < 0) {
            return "Negative";
        } else {
            return "Zero";
        }
    }
}

public class Main {
    public static void main(String[] args) {
        MyClass obj1 = new MyClass(10);
        MyClass obj2 = new MyClass(-5);
        
        if (obj1.toString().equals("Positive")) {
            System.out.println("obj1 is positive");
        }
        
        if (obj2.toString().equals("Negative")) {
            System.out.println("obj2 is negative");
        }
    }
}