Elegant pattern for validating a set of input parameters in java

I'm struggling to find an elegant solution to a validation problem. the problem looks like this.

I have a set of input parameters: p1, p2, p3, p4 (They are received as key value pairs, type Object). Each parameter can have multiple predefined values and only a few combinations are valid. Examples of valid combinations:

• p1=Va, p2=Vb, p3=V123, P4=Vabc
• p1=Vb, p2=Vb, p3=V123, P4=Vabc
• p1=Vc, p2=Vb, p3=V123, P4=Vxyz (where all Values Vxxx are predefined constants)

If the valid combinations would be static, I would create a holder class and create of static collection with all possible combinations of parameters.

But, in some cases one of the parameter could vary, and still be a valid data set. For example: P1 could be predefined constant, or could be some arbitrary numeric ID. In this case a valid set of data would be:

• p1=[any numeric value], p2=Vn, p3=V123, P4=Vnnn

In this case, how can I validate such set of parameters, in which one could take any value and be valid.

I considered a few options but none I would like: 1. describing matching conditions with classic if else statement. not clear enough. Plus, At some point I need a mapping between my predefined combinations to an output constant. 2. I could have a custom equals method in my holder, but I don't like this approach. More, I'm trying to find a generic approach. What if the number of parameters would increase very much, and the number of variable parameters as well.

PS. I could separate the validation in half and do match first the constant parameters, but please remember that one of them can have either predefined constants either arbitrary numbers

Thank you!