创建类型作为原始类型的包装器

Question

Quite often we have projects with a lot of entity types (Hibernate/JPA, ...). The entity types have a primitive type like an int, long or string for an ID. We have DAOs and Services that take and return this primitives.

long doSomething(long blubId, long blabId, long fooId, long barId, ...)

As you can see, it can be very confusing. I'd like to take advantage from the static type checking and have types for it.

long doSomething(BlubId blubId, BlabId blabId, FooId fooId, BarId barId, ...)

But this seems to be inefficient. Do you have any ideas how to solve this issue?

Note, handling with primitives is sometimes required in the JEE context (JSF backed beans, persistency, ...)

Answer 1

This seems like a prime candidate for the builder pattern where you have a DoSomethingOptions class with a DoSomethingOptionsBuilder which creates the options explicitly via named methods to avoid confusion of parameter order.

To be honest, I don't see your initial approach being terribly inefficient, but that really depends on how often your doSomething method is being called and how long the actual logic of the method takes. Obviously using wrappers to primitives will take more space and a marginal amount of time, but it's nearly inconsequential compared to any real computation.

Answer 2

据我了解，您可能会对查找已经编写的Java包装类Java原始包装类感兴趣