If you can change addY() to "return this" then you're in business.
Since it is a third party API maybe you just need a helper function:
Vector makeAndSetupVector(float f1, float f2, float f3, int y) {
Vector vect = new Vector(f1, f2, f3);
vect.addY(y);
return vect;
}
Now you can do:
setLocation(makeAndSetupVector(0f, 4f, 0f, 3));