Command pattern with too many classes

Question

Our legacy code has a long code of if else blocks that depend on events and object type

if(event == A && objectType == O1){
.....
}
else if (event == A && objectType == O2){
 ....
}
else if (....)
....
....

With more and more conditions introducing, I was thinking of replacing this logic with Command pattern for each condition. But the number of classes required would be (no. of events) * (no. of object types). Is there any simpler way to refactor this code?

Answer 1

Create a class enclosing event and objectType, make it implement .equals() and .hashCode(). Create a generic class for each execution block too.

Then you'll be able to use a Map and a simple lookup will return what is needed to execute.