CODEWITHSUNDEEP
javaclassgenericsextend
kalu
kalu

Reputation: 169

Java Generic Class with the Generic-Type extending multiple other classes

I can't wrap my head around it at the moment, maybe that's a stupid question but I give it a go.

Lets say I have these Classes: 

class CellType1 {

    public void doSomething(){
      // does something ClassType1 specific
    }
}

class CellType2 {

    public void doSomething(){
       // does something ClassType2 specific
    }
}

class CellType3 {

    public void doSomething(){
       // does something ClassType3 specific
    }
}

These classes share the same functions but the functions themselves work differently. Now I have this Class:

 class Map<CellTypes>{
   CellTypes cell;

    //...
        public void function(){
           cell.doSomething();
        }

    //...

    }

This Class' Generic Type will later be one of the three upper classes. And in this class I want to access the doSomething()-Function for this specific CellType-Object. I've tried doing

class Map<CellTypes extends CellType1, CellType2, CellType3> {
/*...*/
}

But this limits me to the function/s of CellType1. How can I use the functions from different Classes in a Generic class? Maybe someone has a better idea than me! I hope this was understandable.

Thank you in advance.

EDIT:

I need to have my Class Map as a Generic Class, because I need to create different objects of map and pass them the CellType-class they need to be working with.

Upvotes: 0

Views: 1146

Answers (3)

Ihor Dobrovolskyi
Ihor Dobrovolskyi

Reputation: 1241

You can create an interface:

interface CellType {
    public void doSomething();
}

And implement the interface like this:

class CellType1 implements CellType {

    public void doSomething(){
      // does something ClassType1 specific
    }
}

class CellType2 implements CellType {

    public void doSomething(){
       // does something ClassType2 specific
    }
}

class CellType3 implements CellType {

    public void doSomething(){
       // does something ClassType3 specific
    }
}

Map class:

class Map<T extends CellType> {
   T cell;

    //...
        public void function(){
           cell.doSomething();
        }
    //...
}

Upvotes: 1

Rachit Agrawal
Rachit Agrawal

Reputation: 735

interface CellType {
   void doSomething();   
}
class CellType1 implements CellType {
    public void doSomething(){
        //your logic
    }
}
//similar implementation logic for CellType2 and CellType3
class Map {
   private CellType cellType;
   public Map(CellType cellType){
       this.cellType = cellType;
   }
   public void someFunc(){
      cellType.doSomething();
   } 
}

Hope this helps

Upvotes: 0

Jim Garrison
Jim Garrison

Reputation: 86754

public interface CanDoSomething {
    public void doSomething();
}

Then all the other classes implement this interface. This works only if the method signature is the same in all cases.

Upvotes: 0

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