Re: How much efficient is Java 6 to Java 1.3?

Roedy Green wrote:


To me, one reason is Occam's Razor, loosely speaking. Vector is retrofitted
to the collections class, and contains methods and uses helper types not
supported in the rest of collections. I prefer to use a type that lacks the
redundancies. This gives better control over the code, and increases the
likelihood that the code will play nicely with maintenance, enhancement and
refactoring down the road.

Another factor is that Vector is implicitly synchronized. Uses that
synchronize ArrayList (or other List types) are explicitly synchronized,
increasing the degree to which the source code documents itself. Some people
use Vector without knowing that it synchronizes all its methods. ArrayList
more openly supports a good impedance match between what you see in the source
and the semantics of the resulting program.

Likewise, I prefer to declare variables that point to Lists as Lists rather
than as a specific subtype. Of course there are times when you must specify a
narrower variable type, but one should use the widest type appropriate to the
algorithmic purpose of the variable.

The intuitive summary of this is that ArrayList and the other "true" List
implementations are more elegantly expressive concrete types than Vector for
most use cases.

--
Lew