Implementation using JAVA

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Implementation using JAVA

• DCA-FEEC-UNICAMP

Ricardo Gudwin
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From Design to Implementation

• Design Phase
• development of a logical solution to the problem
• Implementation Phase
• start the process of program construction
• Main Implementation Steps
• Constructive Design
• Coding
• Testing
• Documenting
• Main Results
• Constructive Design Documentation
• Program Code
• Program Manual

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From Design to Implementation

• Constructive Design
• Object reuse
• from older projects
• from development tools APIs and frameworks
• Based on the selected encoding language and
  development tool
• Follows the same basic principles from design
  phase
• Constructive Design Documentation
• Based on design documentation
• Interaction Diagrams
• Software Class Diagrams
• Details the parts of diagrams including reused
  objects and classes
• Contracts are substituted by Method code

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Constructive Design

• Some care with the Constructive Design Diagrams
• Software Class Diagram
• Set of Navigability in associations
• Set of Role Names in associations
• Set of Multiplicity in associations
• Extraction of unnecessary associations
• Interaction Diagram
• Use of extended message notation, when required
• Decomposition to avoid bloated diagrams
• Condition to start Constructive Design
• understanding the objects/classes available from
  the development tool/language APIs and
  frameworks
• mixing reused objects and new objects in a
  consistent way

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Java APIs and Frameworks

• Java Frameworks
• Java Applet Framework - basics for Java applets
• Java Commerce Framework - secure monetary
  transactions
• Java Enterprise Framework - object and
  database-access services for distributed systems
  (includes CORBA)
• Java Server Framework - development of servers
• Java Media Framework - graphics, video, audio and
  animation
• Java Security Framework - authentication, digital
  signatures, encryption
• Java Beans Framework - Java native component
  model
• Objects are distributed within packages
• imported to source code using the import
  instruction

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Java Platform Packages
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Java Platform Packages
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Java Foundation Classes

• Java Foundation Classes (JFC)
• AWT
• Abstract Window Toolkit
• Java 2D
• Java 2D is a graphics API based on technology
  licensed from IBM/Taligent
• Accessibility
• provides assistive technologies, like screen
  magnifiers, for use with the various pieces of
  JFC
• Drag and Drop
• part of the next JavaBean generation, "Glasgow,"
  also available with the Java 2 platform.
• Swing
• set of well-groomed widgets and a framework to
  specify how GUIs are visually
  presented, independent of platform.

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Swing

• Swing widgets
• simply extend AWT by adding a new set of
  components, the JComponents, and
  a group of related support classes.
• are all JavaBeans and participate in the
  JavaBeans event model.
• Subset of Swing widgets
• analogous to the basic AWT widgets.
• lightweight components
• Lightweight component architecture
• introduced in AWT 1.1.
• allows components to exist without native
  operating system widgets
• participate in the Model/View/Controller (MVC)
  architecture
• New widgets
• trees, tabbed panes, and splitter panes

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Swing Widgets
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Creating and Managing Windows

• Panels
• JPanel - The basic container
• Layout Manager
• Organizes widgets within a container
• BorderLayout, GridLayout, FlowLayout, etc
• The Main Window
• JFrame - a window with decorations
• has content panel - JPanel
• Events and Listeners
• Application listeners implement standard listener
  interfaces, based on the desired events
• are further added to the desired component

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Creating and Managing Windows
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Drawing on a Window

• All JComponent (including JPanels) can be drawn
  over
• overriding the method paint
• public void paint(Graphics g)
• The Graphics object
• provide a full set of methods for drawing,
  filling, etc.
• Graphics2D
• extends the Graphics class to provide more
  sophisticated control over geometry,coordinate
  transformations, color management, and text
  layout
• fundamental class for rendering 2-dimensional
  shapes, text and images
• public void paint(Graphics g) Graphics2D g2
  (Graphics2D) g

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Basics on Java

• The starting object
• implements the method main
• public static void main(String args)
• callable from the o.s. environment
• Exceptions
• the try-catch/throws mechanism
• Special objects
• super and this
• Inner Classes
• used to derive specialized listeners and adapters
• Interfaces, Classes and Abstract Classes

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Basics on Java

• Listeners and Adapters
• Listener - interface (need to be implemented)
• Adapter - basic class implementing a listener
  (need to be extended)
• Class Modifiers
• public, abstract, final
• Field Modifiers
• static, final, transient, volatile
• Method Modifiers
• public, protected, private, abstract, static,
  final, synchronized, native
• Special statements
• throw, synchronized

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Basics on Java

• Thread Programming
• The Java Virtual Machine allows an application to
  have multiple threads of execution running
  concurrently
• Priorities
• Daemons and Non-Daemons Threads
• Two ways to create a new thread of execution
• declare a class to be a subclass of Thread
• override the run method of class Thread
• instance of the subclass can then be allocated
  and started by calling its method start
• declare a class that implements the Runnable
  interface
• implements the run method
• instance of the class can then be allocated and
  passed as an argument when creating a Thread
  object that is further started

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Converting Diagrams to Code
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Converting Diagrams to Code