java – 何时为构造函数抛出异常

public Neocortex(Region rootRegion,ConnectionInterface functor) {
this.rootRegion = rootRegion;
this.currentRegion = this.rootRegion;
this.functor = functor;
}

嘿上面我有一个类的构造函数.我的问题是我应该在构造函数中添加空指针异常还是不必要？老实说,我只是不明白何时应该为我的代码添加例外.但在这种情况下,我应该使用哪个构造函数？

public Neocortex(Region rootRegion,ConnectionInterface functor) {
    if (rootRegion == null) {
    throw new NullPointerException("rootRegion cannot be null");
} else if (functor == null) {
        throw new NullPointerException("functor cannot be null");
    }
this.rootRegion = rootRegion;
this.currentRegion = this.rootRegion;
this.functor = functor;
}