COP 4331 OOD

1
COP 4331 OODP

• Lecture 3

2
TYJ Day 5 Creating Classes

• General structure of classes
• The Class Declaration
• The Class Body
• Constructors
• this and super
• Declaring Member Variables
• Method Declaration , Parameters, Method Body
• Implementing Methods
• Access Control

3
Some Classes

• Index of all classes
• class Object
• class Integer
• class String

4
TYJ Day 6 Packages

• Package
• Collection of related classes
• Default access privilege
• In a single directory
• Import eliminates need for full package
  qualification
• import java.util.Vector
• import java.awt.

5
TYJ Day 6 Interfaces

• Interface
• Workaround for multiple inheritance
• Specifies functions that must be defined in an
  implementing class
• A class implements an interface

6
TYJ Day 6 Inner Classes

• Inner class
• Defined inside another class
• Can only be used inside that class

7
TYJ Day 7 Exceptions.1

• Mechanism to handle
• Errors
• Unusual situations
• Exception classes
• Error (major errors)
• Exception (less serious)
• Runtime exceptions
• Other exceptions

8
TYJ Day 7 Exceptions.2

• classs Throwable
• class Error
• class Exception
• Exception handling
• try catch
• Methods that throw exceptions
• The throws clause documents that a method may
  throw a specified exception that must be caught
  or specified further

9
TYJ Day 7 Exceptions.3

• Throwing and defining exceptions
• The throw statement
• Creating exception subclasses

10
TYJ Day 7 Threads.1

• Threads allow several portions of a program to
  run concurrently
• Designing effective threaded programs can be
  quite complex
• Beyond the scope of this course
• But some Java programs use threads in a set way

11
TYJ Day 7 Threads.2

• Threads are implemented in class Thread
• Method start() starts thread
• Method sleep()
• Classes using threads implement the Runnable
  interface
• Must have run() method