How to work with Numbers in Java
At first glance looks easy choose what kind of number use, but sometimes the system grow up and the first kind choose became useless.
So, let’s remember how many and best choice so far when you have to make a choice regarding the number.
Why should I use a number?
The answer looks easy sometimes, because my table has the PK (primary key) as int, long etc. But sometimes the choice is based on math operations, calculate, estimate and so on.
Let’s remember, is not a rule use a number for PK, since you can choice for instance work with UUID.
Difference between primitives and wrappers
There are some differences, such as: initialize the primitives, memory footprint.
Nowadays is not necessary convert to primitive to wrapper and vice-versa. This process is named as autoboxing/unboxing.
See below the primitive use and the current instance of each number.
Flavors of Number
In Java 11 there are 15 classes that extends Numbers, there classes are:
Let’s pass one by one and in the end you can choose the best for you.
Conclusion
Based on the good practice in know your domain and anticipate capacity problems so think about how the field/column can grow and if an number is correct to use instead of string type.
Prefer bigger types in doubt case.
References
https://docs.oracle.com/en/java/javase/11/docs/api/index.html. Accessed 24 June 2019.
Best regards,
Luiz
