faster way to create object lombok builder vs manually declaration

Question

Between these 3 way to create an object, which one is the faster in time of execution?

Amount.builder().categoryCode("A").coveredAmount(new 
BigDecimal(100)).build();

or

Amount cva1 = new Amount();
cva1.setCoveredAmount(new BigDecimal(100));
cva1.setCategoryCode("A");

or

Amount cva1 = new Amount(new Bigdecimal(100), "A");

And the number of fields can be made difference?

Answer 1

Lets evaluate how many stack frames each syntax has (just a rough diagram, excuse my brevity):

1) builder() ->returns -> categoryCode() -> return this -> coveredAmount() -> return this
-> new BigDecimal() -> return BigDecimal -> return this -> finally build() -> returns Amount

So total 6 function calls.

2) ctr call -> return Amount -> setter -> bigdecimal -> return bigdecimal -> return setter -> (same again as last step)

So total 5 calls

For 3) only 2 function calls

By above analysis 3rd syntax wins but your compiler might optimize in such manner that all three would have similar execution time.

Answer 2

Beyond the performance comparison (peanuts btw...) you should not use a object-creation strategy based on his execution time but merely on your real need, requirements and best practices.

1. Fluent Builder pattern

   • Better for readability
   • Optional attributes
   • Construction in multiple step

Remark : don't use this pattern to hide the fact that your class defines too many fields... use pattern like extract class instead of going through a builder construction.

2. Javabean style . This type of construction is (IMO) a bad practice because the time between the no-arg construction and calls to setters to initialize it, the object stills in an inconsistent state.

3. Primary constructor . You prefer this way when all fields are required .