Generic methods returning dynamic object types

Question

Possibly a question which has been asked before, but as usual the second you mention the word generic you get a thousand answers explaining type erasure. I went through that ph

Answer 1

You could try type tokens:

public  T getValue(Class cls) {
    if (valVal == null) return null;
    else {
        if (cls.isInstance(valVal)) return cls.cast(valVal);
        return null;
    }
}

Note, that this does not do any conversion (i.e., you cannot use this method to extract a Double, if valVal is an instance of Float or Integer).

You should get, btw., a compiler warning about your definition of getValVal. This is, because the cast cannot be checked at run-time (Java generics work by "erasure", which essentially means, that the generic type parameters are forgotten after compilation), so the generated code is more like:

public Object getValVal() {
    return valVal;
}