1. Java 1.5 New Features

2. java.applet, java.awt, java.io, java.lang, java.net, java.util java.math, java.rmi, java.security, java.sql, java.text, java.beans javax.accessibility, javax.swing, org.omg javax.naming, javax.sound, javax.transaction java.nio, javax.imageio, javax.net, javax.print, javax.security, org.w3c javax.activity, javax. management Java 1.0 8 packages 212 classes Java 1.1 23 packages 504 classes Java 1.2 59 packages 1520 classes Java 1.3 77 packages 1595 classes Java 1.4 103 packages 2175 classes Java 1.5 131 packages 2656 classes New Events Inner class Object Serialization Jar Files International Reflection JDBC RMI JFC/Swing Drag and Drop Java2D CORBA JNDI Java Sound Timer Regular Exp Logging Assertions NIO

3. New Features Scanner Printf Autoboxing Enumerated Types Foreach loop Generic Types

4. Other New Features Static import: import static java.Math.*; Variable length argument lists. Semaphores Metadata

5. java.util.Scanner Scanner stdin = Scanner.create(System.in); int n = stdin.nextInt(); String s = stdin.next(); boolean b = stdin.hasNextInt()

6. printf method Similar to C style printf Handles –strings –native types –numeric types –java.util.Date See java.util.Formatter for details

7. Autoboxing/Unboxing Wrap ints into Integers Extract ints from Integers This is now legal: Integer x = 6;//6 is boxed Integer y = 2*x + 3;//x is unboxed, 15 is boxed You could hide primitives entirely!

8. Object Only Performance int x = 6; int y = 2*x; Code: 0:bipush6 2:istore_1 3:iconst_2 4:iload_1 5:imul 6:istore_2

9. Object Only Performance Integer x = 6; Integer y = 2*x; Code: 0:bipush6 2: invokestatic#2; //Method java/lang/Integer.valueOf:(I)Ljava/lang/Integer; 5:astore_1 6:iconst_2 7:aload_1 8:invokevirtual#3; //Method java/lang/Integer.intValue:()I 11:imul 12:invokestatic#2; //Method java/lang/Integer.valueOf:(I)Ljava/lang/Integer; 15:astore_2

10. Object Only Performance Integer x = Integer.valueOf(6); Integer y = Integer.valueOf(2 * x.IntValue); Generates the same byte code.

11. Type-safe enum enum Day { SUNDAY, MONDAY, TUESDAY, WEDNESDAY, THURSDAY, FRIDAY, SATURDAY } //used Day today = Day.WEDNESDAY; switch(today){ case SUNDAY: break; //… }

12. More Complex Enum enum Suit { CLUBS(Color.BLACK), DIAMONDS(Color.RED), HEARTS(Color.RED), SPADES(Color.BLACK); private Color color; Suit(Color color) { this.color = color; } public Color getColor() { return color; } }

13. Generics ArrayList list = new ArrayList (); list.add(new Integer(5)); list.add(6); list.add(new Double(3.14159/2)); list.add(new BigInteger("123456789012301234567890")); list.add(new Long(127L)); Number n = list.get(i);

14. Defining Generics public class GenericStack implements Iterable { private T[] data; … public GenericStack() { data = (T[])new Object[MIN_SIZE]; … } public T pop(){ … } public void push(T item) { … } public Iterator iterator(){ … } //since it is iterable }

15. Defining Generic Iterator //inner class of GenericStack private class GenericStackIterator implements Iterator { int index; GenericStackTestIterator() { index = top; } public boolean hasNext() { return index >= 0; } public T next() { if(index < 0) { throw new java.util.NoSuchElementException(); } T item = data[index]; index--; return item; } public void remove() { throw new UnsupportedOperationException( ) }

16. For each loop (arrays) double[] array = {2.5, 5.2, 7.9, 4.3, 2.0}; for(double d: array) { System.out.println(d); } Iterate (forward) through the array without paying attention to indices.

17. For each loop (Collections) ArrayList list = new ArrayList (); list.add(7); list.add(15); list.add(-67); for(Integer number: list){ System.out.println(number); }

18. For each loop enums for( Suit s: Suit.values()){ System.out.println(s.getColor()); } values() returns an Iterator for enum types

19. Wish list Preprocessor –Embedded languages: SQL, Regular Expression syntax. Operator Overloading –Assignment –Equality –[ ] for Lists

20. Classroom Incorporation Investigate use with undergrad. Example: Servlets/JSP in Databases JavaCard in Architecture. Metadata for Generating Code in Compilers

21. References Calvin Austin. J2SE 1.5 in a Nutshell. http://java.sun.com/developer/technicalArticles/releases/j 2se15 http://java.sun.com/developer/technicalArticles/releases/j 2se15 Gilad Bracha. Generics in the Java Programming Language. http://java.sun.com/j2se/1.5/pdf/generics- tutorial.pdfhttp://java.sun.com/j2se/1.5/pdf/generics- tutorial.pdf David Flanagan. Java in a Nutshell. O’Reilly. 1 st, 2 nd and 3 rd editions. Cay Hortsmann and Gary Cornell. Core Java 2. Prentice Hall.

22. Examples online http://cs.gettysburg.edu/~cpresser/java The latest additions will be made next week Including this presentation. email: cpresser@gettysburg.edu

23. The End….

24. No, really. Stop clicking.

25. Java History –New event model –Inner classes –Object Serialization –JAR files –Internationalization –Reflection –Java Database Connectivity (JDBC) –Remote Method Invocation (RMI) Java 1.0 8 Packages, 212 Classes Java 1.123 Packages, 504 Classes

26. Java History –JFC (Swing) –Drag and Drop –Java 2D Java 1.2 59 Packages, 1520 Classes –Java Naming and Directory Interface (JNDI) –Java Sound –Timer class Java 1.3 77 Packages, 1595 Classes

27. Java History –Regular Expressions –Assertions –Logging –New I/O (NIO) Java 1.4 103 Packages, 2175 Classes –What, and ruin the surprise? Java 1.5 131 Packages, 2656 Classes