Preview of Java 1.5
gafter writes "An early access prototype implementation of
the proposed new J2SE 1.5 language features is
available. The prototype includes
generics (JSR 14),
typesafe enums, varargs,
autoboxing, foreach loops, and static import
(JSR 201). In other words, all the new language features
planned for 1.5 except
metadata (JSR 175). The
prototype includes full sources for the compiler,
written in the extended language. You can download the prototype from
java.sun.com.
It requires J2SE 1.4.1 and provides some examples of how to use the new language constructs. The prototype includes an experimental type
system (variant type parameters)
for Generic Java that is being considered
for Tiger (1.5) based on a paper by
Igarashi and
Viroli at ECOOP 2002 .
Comments and votes for the new type system are
being gathered at
bugParade."
While, as a java developer, I'm looking forward to most of these changes, I'm a bit afraid that java may lose it's positions as simple OO language which can be used for teaching in schools. Java was originally built with idea that you can read every java program in the world without problems. A lot of expresive power was sacrificed because of that - most notable preprocessor (to avoid people designing their own 'languages' for each project and library, as it is done in C).
Anonymous inner classes was first major ugliness which came into language - not very clear, hard to explain to a newcomer. But with all these new proposals, significant complexity is added to code in terms of visual overview. This is not critical for developers - perl hackers are faring very well, despite of having language 10 times as complicated as java as far as syntax is concerned - but pure-OO, java-is-new-pascal-for-algorithms academic society will probably start looking for a new language soon... (ok, maybe not really 'academic', I'm thinking more about secondary-level school programming basics).
...because there's nothing like running a 2kb calculator and a 2kb notepad and both have them run on separate 10-15mb VMs. That is a real drag for any non-monolithic use of Java (yes I do know of servlets etc.)
Kjella
Live today, because you never know what tomorrow brings
These additions seems to put Java on par with C#, but to make a quantum leap in expressiveness you need a dynamically typed scripting language.
Most applications these days can be written in higher-level languages, resulting in 5-10 times less source code compared to Java/C#, and making them correspondingly simpler to code and maintain.
Java doesn't really have a kick-ass companion scripting language. In MS world, VB plays this role. VB is really popular, but (I think most people would agree) a crap language and not really that high level. JavaScript just doesn't seem to cut it (pretty much only used in browsers).
Why doesn't Sun take a hint and phase JavaScript out in favor of a powerful multi-purpose high-level language like Python or Ruby? That'll put them miles ahead of Microsoft in terms of increasing programmers' productivity... and programmers' quality of life.