I ran
into a cute trick while coding a unit test on a Spring application the other
day that I'd like to share.
Consider
these lines of Java code.
The first
line requires a cast. the reason is that the method returns an Object. While the cast
isn't the most labor intensive construct, but it makes code less clear and is
inconvenient to developers.
Note that
the second line does *not* require the cast making it much more convenient for
developers. the secret is that Spring's ReflectionTestUtils uses generics.
take a peak at how invokeMethod is defined.
In
effect, Java infers the type of the value returned by the definition of the
variable it is assigned to. In this case, it's a String.
This is convenient
for developers in that there's less to type, but also more easily read.
You
should not that the developer is required to know what type of value is
returned. The following statement will generate a ClassCastException.
This
might seem like a disadvantage to using generics in this way. I don't think so.
In either case, the developer needs to understand the data type that will
actually be returned.
Just
thought I'd pass this tid bit along. I'll certainly think more about using
generics in this way in APIs I write.
