JavaLanguage Section Index | Page 5

Date d = new Date(System.currentTimeMillis() + Timer.ONE_DAY);

Methods like printf allow you to pass multiple arguments to a method without having to explicitly declare versions for each "count" of arguments. For the final parameter type, use three periods, a...more

Add ... to the end of the top level package name, along with the required -ea / -enableassertions command line switch, as in java -ea:com.example.foo... FooClass.

Starting in Java 5, you can use the new enum keyword, where you would specify a class or interface. For instance, for a enumeration of suits from a deck of cards, you might use: public enum Suit {...more

Starting in Java 5, you can use the new enum keyword, where you would specify a class or interface. For instance, for a enumeration of suits from a deck of cards, you might use: public enum Suit {...more

If Suit is declared as an enum, named suit, then suit.values() will return an array of elements, one for each value in the enum set.more

It lets you avoid qualifying static members with class names. If you import static java.lang.Math.PI; you can then use PI without qualifications.

There are a number of annotations built in to the java 5.0 API. Within java.lang.annotations, there are a number of annotations that can be used when working with annotations ("annotation to ann...more

You can't directly by using wait and notify, but the can use a similar construct with the Lock interface of the java.util.concurrent.locks package, with its boolean tryLock(long time, TimeUnit uni...more

Any class that implements the Iterable interface can be used in a for-each statement: for (Datatype localvar : Iterable-instance). For instance, the following will print out each command-line argu...more

The best you can do is sign up as a contributor to Mustang, Sun's 6.0 release of Java SE. There is information on collaborating at https://mustang.dev.java.net/collaborate.html.more

As of JDK 5.0, the Java programming language now supports hexadecimal floating point literals. 0XfP3 = 120. The 0X prefix means what follows is hex. F = 15. P3 means 2 ^ 3 (2 raised to third power...more

The @Override annotation can be added to the javadoc for the new method. If you accidently miss an argument or capitalize the method name wrong, the compiler will generate a compile-time error.more

Autoboxing is not casting. Instead, it is the automatic conversion of a primitive data type to its wrapped Object type (boxing) and back (unboxing). For instance, Integer i = 3;, used to generate ...more

The TimeUnit class allows you to work with time quanities as both an amount and a unit of measurement. For instance, instead of always working with milliseconds when you want to put a thread to sl...more