COP 3331 Object Oriented Analysis and DesignChapter 8 – Object-Oriented Application Framework Jean Muhammad Reference – Object Oriented Software Development Using Java - Jia
Overview • Application Frameworks • Collections Frameworks • AWT and SWING • Input/Output Framework Reference – Object Oriented Software Development Using Java - Jia
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. Reference – Object Oriented Software Development Using Java - Jia
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. Reference – Object Oriented Software Development Using Java - Jia
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 Reference – Object Oriented Software Development Using Java - Jia
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->. They are also known as functions, dictionaries, or associated arrays. Keys must be unique {k1->v1, k 2->v2, k3->v3, k4->v4, .. kn->vn} • Sort Maps: Elements are sorted by keys. Reference – Object Oriented Software Development Using Java - Jia
Applications Frameworks • Interface Collections • Common aspects of a class should be handled in a uniform manner. Collection Map Set List Sortedmap SortedSet Reference – Object Oriented Software Development Using Java - Jia
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 Reference – Object Oriented Software Development Using Java - Jia
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. Reference – Object Oriented Software Development Using Java - Jia
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) Reference – Object Oriented Software Development Using Java - Jia
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() Reference – Object Oriented Software Development Using Java - Jia
Concrete Collections - Discussion • HashSet IdentifyHashMap • LinkedHashSet LinkedHashMap • TreeSet TreeMap • ArrayList HashTable • LinkedList • Vector • HashMap Reference – Object Oriented Software Development Using Java - Jia
Methods of Interface Iterator • hasNext() • next() • remove() Reference – Object Oriented Software Development Using Java - Jia
Methods of Interface ListIterator • add(o) • hasNext() • hasPrevious() • next() • nextIndex() • previous() • previousIndex() • remove() • set(o) Reference – Object Oriented Software Development Using Java - Jia
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). Reference – Object Oriented Software Development Using Java - Jia
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 Reference – Object Oriented Software Development Using Java - Jia
Swing Components Component Container * JComponent JButton JPanel Window JLabel JCombBox JApplet Frame Dialog JCheckBox JList JFrame JDialog JScrollBar JWindow JTextComponent JTextField JTextArea Reference – Object Oriented Software Development Using Java - Jia
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. Reference – Object Oriented Software Development Using Java - Jia
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 Reference – Object Oriented Software Development Using Java - Jia
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. Reference – Object Oriented Software Development Using Java - Jia
