Maybe this session sounds like old hat, but I’m looking for more ammo to add to the list of reasons we should jump to Java 5 from either 1.3 or 1.4, and sooner rather than later. Already on the list is that we’d like to get to Tomcat 5, and introduce Hibernate. In introducing Hibernate, I’d prefer to go straight to H3 with annotations rather than do a double effort of implementing Hibernate with typical mappings or XDoclet, and then moving to annotations. Venkat Subramaniam is presenting.
I’m going to go about this session a bit different and actually post the entry now, and update it as the session progresses.
- Autoboxing – the nice syntax cleanup that turns a bunch of casting from primitives to objects (int to Integer and back). I know that it’s just Java doing all the casting behind the scenes, but I like the way it takes some of the ugly and tedious code out of Java source. The gotcha I wasn’t aware of is that if you write “int myInt = myArray;” on an Integer, and the element in the array has a null value, you get a NullPointerException. Ouch.
- Happier for loops – for(int i=0; i
- enums – nice to finally see a sane way of expressing enums in the Java language. Once again, it’s little more than magic hand-waving behind the scenes, but it’s a real improvement to readability, and short-circuits the constants-as-static-final-variables-in-an-interface anti-pattern, with type-safety as a bonus. Some folks have a real beef with Java shoe-horning these features into the language, I give them a ton of credit for accomplishing their magic in the compiler rather than mangling the runtime with all of these features. I also haven’t seen this magic of adding a method to an enum – very interesting. EnumSet and EnumMap are also news to me.
- varargs – I hadn’t even heard of this until today. More nifty syntax sugar that allows you to supply a variable number of arguments to a method, with type safety. Declare your method public static void doStuff(String…), and you can call it with doStuff(“one”), doStuff(“one”, “2”, “three”) – Java will, behind the scenes, make your method accept a Sttring, and bundle up your method call parameters into a String. Very cool.
- Annotations – one of my favorite new features in Java 5, based on the headache it relieves in creating Hibernate mappings. Defining an interface is quite wacky, but I think far more people will be using annotations than defining them.
- Static Import – Venkat isn’t a fan of this feature, and neither am I. Static import lets you import all of another class’ static methods and call them without even naming the class they belong to. The methods are called just as if they were defined inside the class. This looks like it has major confusion potential, with a minimal value-add.