Java - 实例变量依赖于构造函数参数

Question

I want to set a variable which is dependent on the argument passed to the constructor. At the moment my code looks something like this. Is calling a method here bad practice and is there a better way of doing this? I have searched for an answer but haven't been able to find anything. All help appreciated.

public class Test {
    int num;

    public Test(int num) {
        this.num = prime(num);
    }

    public int prime(int num) {
        //code to get a prime number
    }   
}

Answer 1

Calling a method from constructor is bad practice if it is an overridable method. With overridable methods you get into initialisation order troubles. See this question .

You should make your prime() method private, static or final.