Java 1.5

Java 1.5
Ethan Bolker and Gabriel Rodriguez
Spring, 2004

The beta release of Java 1.5 is now available from java.sun.com/j2se/1.5.0/index.jsp

From our perspective, the most important features in that release are those that make collections much easier to use. In particular

Casts are no longer required when retrieving Objects from a Collection
Collection objects will automatically wrap primitive types when required - Sun calls this "autoboxing"
The Iterator idiom has been replaced by an enhanced for loop syntax that's much easier to use.

You can read about these new features (and others) at Sun's J2SE 1.5 in a Nutshell - scroll down to Generic Types.

To compile code using these new features, use the command

	javac -source 1.5 Whatever.java

Code that does not use the new features compiles with the ordinary javac command. If you compile old ArrayList or TreeMap code with the -source 1.5 option, you will see warning messages.

I have used the new features in TreeMap15Demo.java . It has the same functionality as the old TreeMapDemo.java

You can find lots of examples (and discussion) on the web. Just google java 1.5

If you would like to experiment with Java 1.5, you must do so on your home PC - updating the version in the lab in the middle of a semester is too risky. But we will probably allow you to use Java 1.5 for your homeworks if you wish, because we can safely make arrangements to compile what you turn in.

Prof. Cambpell and I will decide soon on how to update the JOI source code on line in a way that's as consistent as possible with what's in the book.