Summary

1
Summary

• We have barely scratched the surface, both in
  terms of Java as well as OO

2
Java

• Not covered
• C.21 applets
• C.22 network programming ( 312 next year)
• Java 2
• Improved Collection class stuff
• Swing in addition to AWT
• Better graphics Java2D, Java3D
• Internationalization
• Java beans
• JNI java native interface
• Sound
• JDBC connect to SQL databases
• RMI remote method invocation
• Servlets

3
Java development

• Java 1.3
• Lots of improvement to libraries
• (HotSpot)
• Reflection
• Corba
• Applet caching/jar indexing
• Java 1.4
• NIO New IO API
• XML
• Better Swing performance
• Assertion facility
• AWT full-screen mode, headless support, better
  focus architecture
• Java 1.5
• Generics (templates)

4
Object-oriented concepts

• Multiple inheritance
• Not just interface, but also implementation (
  code)
• Need conflict resolution
• Inherit same names (fields or methods) along
  multiple pathes
• C user must specify explicitly
• Dylan, Common Lisp automatic, use a
  class-precedence list

5
Prototypes

• No distinction between Class and Instance
• Every instance can be used as the Prototype
  (class) for other instances, use socalled
  delegation instead of methods
• Usually rather dynamic
• SELF system (was also important milestone for JIT
  research)
• NewtonOS

6
Generic functions (Dylan, CL)

• All parameters influence method selection (cf.
  parametric overloading 2step process)
• Generic functions all arguments runtime types
  influence choice (theoretically slower)
• Not directly attached to a single class
• defeats(Object a, Object b) return false
• defeats(Paper a, Rock b) return true
• defeats(Rock a, Scissors b) return true
• defeats(Scissors a, Paper b) return true

7
Predicate dispatch
public int f(A x, B y) when x.df1() instanceOf C
or not(y instanceOf D)
Predicate dispatch Multiple dispatch Single
dispatch
Cecil, Dylan, CL, Java, C, Smalltalk,
Delphi,
8

• Keep (having fun)
• learning about Java (and possibly other
  programming languages)
• practising by writing more and more complex
  programs
• How
• 3rd/4th year papers
• Books (library)
• Internet (WWW, newsgroups, mailing-lists)