try/catch vs null check in java

Question

Sometimes I face I must write a piece of code like this (usually it have more nested if and more complex structure but for the example is enought)

public voi         


        

Answer 1

public void printIt(Object1 a){
    if(a==null){
        throw new IllegalArgumentException("a was null, but this is not allowed here."),
    }
    [...]

Fail fast and fail hard. If a shoud not be null, throw an Exception. This will make your code more stable and reliable.

So if I would have to decide between your a) and your b), I would choose a). But if a mustn't be null there, you would hide an error-situation.