Change a class constructor depending on other parameters

Question

I am doing an UML diagram for my Java Application, and I came across with the following doubt:

I have a class called Information, its attributes depends on what kind of Node it is.

For example:

If Node = TrafficLight , Information will contain the color of the light.
But if Node = Signal , it will contain the maximum speed.

How can I implement that, both in UML and code?

---

Thank you all for your answers, I will try some of them and I will post the solution!

Answer 1

I'm going to assume that Node is a child of the Information object. In this case, you would need an object for each of the possible outcomes which Node could be. The best way I can explain this is...

package.name.Node
  |
  |_package.name.Node.Information
     |
     |_Information.TrafficLight(String color)
     |
     |
     |_Information.Signal(Double speed)

I hope that helps. Keep in mind that I've not programmed in Java in a long while but I happened across this and remembered doing something similar in college ^_^; since it's just UML you should be able to get an idea of where to go with your project from his, assuming I'm not just making a fool of myself. Like I said, just trying to help.

Answer 2

You can invoke method overloading on constructors in java.

public class myClass{
    public myClass(){
       //do something
    }
    public myClass(String someInput){
        this.someInput=someInput;     
    }
 }

Answer 3

That is what I finally did:

Create a method called addNode(nodeType)

addNode(nodeType){

   switch (nodeType){
      case trafficlight:
         new TrafficLight //call one constructor
      case signal:
         new Signal //call other constructor
   }  
}

Thanks for your help!