COP 3331 Object Oriented Analysis and Design Chapter 8

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COP 3331 Object Oriented Analysis and
DesignChapter 8 Object-Oriented Application
Framework

• Jean Muhammad

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Overview

• Application Frameworks
• Collections Frameworks
• AWT and SWING
• Input/Output Framework

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Applications Frameworks

• A framework is defined as a set of collaborating
  classes that represent usable designs of software
  systems that have some application for a
  particular domain. The main goal of an
  application framework is to support the reuse of
  designs.

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Applications Frameworks

• Characteristics
• Extensibility A framework consists of a set of
  abstract classes and interfaces to be extended
  and specialized.
• Inversion Control Frameworks represent a higher
  level of abstraction then we normally think of.
  Instead of the application controlling the flow
  of execution, it will be the framework.
• Design Patterns as Building Blocks Design
  patterns are a schematic description of reusable
  components while frameworks are executable
  programs.

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Applications Frameworks

• Design Requirements
• Completeness A framework must provide a family
  of classes.
• Adaptability All platform-specific aspects of
  the framework must be clearly identified and
  isolated.
• Efficiency Components must be easily identified
  and documented.
• Safety Each abstraction must bye type-safe to
  avoid behavior problems.
• Simplicity Must have clear and consistent
  organization.
• Extensibility Must be able to add new classes

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Applications Frameworks

• The Collections Frameworks An object that
  contains other objects.
• Bags A collection of unordered elements. May be
  duplicates. Least restrictive.
• Sets An unordered collection of elements. No
  duplicates are allowed e1, e2, e3, e4,.. en
• Lists An ordered collection of elements.
  Duplicates are allowed.
• Maps A collection of unordered collection of
  key-value pairs denoted by key-gt. They are also
  known as functions, dictionaries, or associated
  arrays. Keys must be unique
• k1-gtv1, k 2-gtv2, k3-gtv3, k4-gtv4, .. kn-gtvn
• Sort Maps Elements are sorted by keys.

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Applications Frameworks

• Interface Collections
• Common aspects of a class should be handled in a
  uniform manner.

Collection
Map
Set
List
Sortedmap
SortedSet
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Methods of Interface Collection

• add(o)
• addAll(c)
• clear()
• contains(o)
• containsAll(c)
• isEmpty)
• iterator()
• remove(o)
• removeAll(c)
• retainall(c)
• size()
• o is an object , c is a type collection

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Methods of Interace set

• This extends the Collection interface
• add(o) adds the elements, checks to make sure
  there are no duplicates.
• addAll(c) Adds elements if they are not already
  present.

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Methods of Interface List

• List interface also extends Collection interface
• add(i,o) - remove(i)
• add(o) - remove(o)
• addAll(c) - set (i,o)
• addAll(i,c) - subList(i,j)
• get(i)
• indexOf(o)
• lastIndexOf(o)

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Methods of Interface Map

• Does not extend Collection or Set interface
• clear()
• containsKey(k)
• containsValue(v)
• entrySet()
• get(k)
• isEmpty()
• keySet()
• put(k,v)
• putAll(m)
• remove(k)
• size()
• values()

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Concrete Collections - Discussion

• HashSet IdentifyHashMap
• LinkedHashSet LinkedHashMap
• TreeSet TreeMap
• ArrayList HashTable
• LinkedList
• Vector
• HashMap

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Methods of Interface Iterator

• hasNext()
• next()
• remove()

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Methods of Interface ListIterator

• add(o)
• hasNext()
• hasPrevious()
• next()
• nextIndex()
• previous()
• previousIndex()
• remove()
• set(o)

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AWT and SWING

• GUI components Known as widgets. Examples
  include button, label, checkbox, scrollbar,
  frame, dialog
• Layout Managers Define strategies for laying out
  GUI components. Commonly used layout managers
  include FlowLayout and BorderLayout
• Events and event listeners Represent user input
  or actions. KeyEvent, MouseEvent are examples.
• Graphics and Imaging classes Allows components
  to be drawn. Graphics(Color, Font, Graphics,
  etc). Geomentry (Point, Rectangle, Dimension,
  etc), Imaging( Image, Icon, etc).

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GUI Component Classes in AWT
Component

Button
Container
Canvas
Panel
Window
CheckBox
Choice
Frame
Dialog
Label
FileDialog
List
Scrollbar
Java.applet.Applet
TextComponent
TextArea
TextField
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Swing Components
Component
Container

JComponent
JButton
JPanel
Window
JLabel
JCombBox
JApplet
Frame
Dialog
JCheckBox
JList
JDialog
JFrame
JScrollBar
JWindow
JTextComponent
JTextField
JTextArea
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Input/Output Framework

• Stream I/O Sequence of bytes. A stream may be
  opened for reading and writing but not both.
• Random Access I/O Random access I/O supports
  reading and writing data at any position in the
  file. A random access file may be opened for both
  reading and writing.

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Byte Streams

• Input Method Output Method Description
• read() write(b) Reads/Writes single byte
• read(ba) write(ba) Reads/Writes byte array
• read(ba,off,leng) write(ba,off,leng)
  Reads/Writes segment of
• byte array
• skip(n) Skips over n bytes
• close () close() Closes the stream

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Random Access Files

• Constructor
• RandomAccessFile(filename,mode) Creates a
  random-access file that reads from, and
  optionally writes to, the file name filename. The
  mode argument is a strng whose value must be
  either r, for ready only, or rw, for
  read-write.
• seek(L) Move the read/write position to the L-th
  byte.
• skipBytes(i) Moves the read/write position I
  bytes relative to the current position. Moves
  forward or backward.