ArrayList cars = vehicles.getExtras();
Iterator it = cars.iterator();
while(it.hasNext()){
Extra cExtra = (Extra)it.next();
if (cExtra.getExtraId()==INSURANCE)
insurance = cExtra.getExtra();
if (cExtra.getExtraId()==ROAD_ASSISTANCE_CODE)
roadAssCode = cExtra.getExtra();
if (cExtra.getExtraId()==TYPE)
replacementCarServiceType = cExtra.getExtra();
if (cExtra.getExtraId()==CATEGORY)
replacementCarCategory = cExtra.getExtra();
if (cExtra.getExtraId()==ASSISTANCE){
roadAssistanceCode = cExtra.getExtra();
}
我有更多这些'if'类型,我没有包括在内。 我怎么能重构这个,所以可以减少圈复杂度。
答案 0 :(得分:2)
Polymorphism is usually the key to reducing CC。如果你有一组类似的东西,它们做类似但不同的东西,那么也许这些东西可以从一个公共基类继承,但是覆盖某个方法来提供不同的行为。
有时你可能会听到人们宣称你可以使用多态来删除所有ifs,但是这两个极端之间通常存在很好的平衡。您通常希望首先努力满足SOLID principles并且将会降低CC。
本书重构:改进现有代码的设计是一本非常好的读物。显然重构模式也是如此,但我还没读过。
以下是一个如何重构代码以获得1的圈复杂度的示例(我不知道您的代码是如何设置的,但我想我重新创建了它的想法):< / p>
import java.util.ArrayList;
import java.util.List;
public class ExtraTest {
public static void main(String[] whatsUp) {
MyData myData = new MyData();
List<Extra> myExtras = new ArrayList<>();
myExtras.add(new ExtraInsurance("ReallyBadInsurance"));
myExtras.add(new ExtraCarCategory(CarCategory.really_big_truck));
System.out.println("Data before: " + myData);
myExtras.forEach(extra -> extra.applyExtra(myData));
System.out.println("Data after: " + myData);
}
public static enum CarCategory {not_a_truck, truck, big_truck, really_big_truck}
public static class MyData {
String insurance = "none";
CarCategory carCategory = CarCategory.not_a_truck;
@Override
public String toString() {
return insurance + " : " + carCategory.toString();
}
}
public abstract static class Extra<T> {
protected final T extraAttributeToProvide;
public Extra(T extraAttributeToProvide) {
this.extraAttributeToProvide = extraAttributeToProvide;
}
public abstract void applyExtra(MyData myData);
}
public static class ExtraInsurance extends Extra<String> {
public ExtraInsurance(String extraAttributeToProvide) {
super(extraAttributeToProvide);
}
public void applyExtra(MyData myData) {
myData.insurance = extraAttributeToProvide;
}
}
public static class ExtraCarCategory extends Extra<CarCategory> {
public ExtraCarCategory(CarCategory extraAttributeToProvide) {
super(extraAttributeToProvide);
}
public void applyExtra(MyData myData) {
myData.carCategory = extraAttributeToProvide;
}
}
}
输出:
之前的数据:无:not_a_truck
之后的数据:ReallyBadInsurance: really_big_truck