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Introduction to Advanced
Java Programming
Chapter 1
Java Programming: Advanced Topics
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Objectives
• Review what Java is and differences between
the three editions of the Java 2 platform: J2SE,
J2EE, and J2ME
• Explore the context in which Java and related
technologies are evolving
• See how Java supports object-oriented
programming and look at some popular design
patterns
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Objectives (Cont.)
• Learn how to use the basic tools that
version of Java 2 Software Development
Kit provides, especially javac, java,
javadoc, and jar
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Overview of the Java Platform
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The Java language is object-oriented
Java code is architecture-neutral and portable
Java is network-savvy
Java programs are secure
• Java is high performance
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Java Programs and Components
• JavaBeans: classes or program components
that conform to strict programming conventions
• Applets: components that can be launched from
HTML documents and run in a Web browser or
applet viewer utility
• Servlets: components that generate content for
Web pages at runtime
• Enterprise JavaBeans (EJBs): server-side
components used in distributed enterprise
environments
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The Three Editions of the
Java 2 Platform
• The Java 2 platform comes in three versions:
– Java 2 Standard Edition (J2SE)
– Java 2 Enterprise Edition (J2EE)
– Java 2 Micro Edition (J2ME)
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Containers in the n-Tier J2EE
Architecture
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A Brief History of the
Java Platform
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•
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•
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1995: Version 1.0 (Sun Microsystems)
1997: Version 1.1
1998: Java 2 platform
1999: J2SE, J2EE, and J2ME
2001: Version 1.3 of J2SE
2002: Version 1.4
2002: Version 1.3 of J2EE
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Object-Oriented Programming
in Java
• The key benefits of object-oriented
programming are:
– code reuse
– flexibility to respond to changing circumstances and
requirements
– ease of maintenance
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Object-Oriented Programming
in Java (Cont.)
• A program is a collection of objects that send
messages to each other
• Object-oriented analysis and design (OOAD):
– First stage: perform object-oriented problem analysis
– Second stage:
• Identify classes to be implemented
• Identify fields and methods the classes must contain to
model the behavior of real-life objects
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Object-Oriented Methodology
• Java lends itself to iterative and incremental
object-oriented development methodology
• In large projects, functionality is typically added in
stages and each identifiable stage is an increment
• An iteration is a short-term development cycle
within an increment
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Object-Oriented Features of Java
• Java supports the following fundamental
features of all object-oriented languages:
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Abstract data types
Encapsulation
Inheritance
Polymorphism
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Design Patterns and Frameworks
• Design pattern: proposed solution to common
design problem
• Frameworks: collections of reusable classes
• Popular design patterns:
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–
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Model-View-Controller design pattern
Singleton design pattern
Factory design pattern
Adapter design pattern
Façade design pattern
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Model-View-Controller Design
Pattern
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An Implementation of the
Singleton Design Pattern
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An Implementation of the
Factory Design Pattern
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Standard SDK Tools
•
•
The Java platform includes a tool set for
developing Java programs
The J2SDK tools run only in a commandline window and provide basic
functionality
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Standard SDK Tools
(Cont.)
•
Standard J2SDK tools:
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javac compiler
java launcher
javadoc documentation builder
jar packaging utility
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How the Launcher Finds Classes
• Java command locates bytecode files by
class name
• Launcher loads bytecode from the file with
the extension .class and with the casesensitive base filename that matches the
class name
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How the Compiler Finds Classes
• For public classes
– Source file must have the same name as the
class
– Every public class must be in a separate file
• javac command has a -sourcepath option to
specify the location of input source files
when different from the location of compiled
classes
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javadoc Comments
• The javadoc tool is a utility for generating
HTML documentation directly from comments
in Java source code
• Doc comments
– Start with a slash and two asterisks (/**)
– Terminate with one asterisk and a slash (*/)
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javadoc Comments
(Cont.)
• Doc comments can appear before the
following kinds of declarations:
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Class
Interface
Field
Method
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javadoc Comments
(Cont.)
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Creating HTML from javadoc
• To get HTML output in the standard format, run the
javadoc program
• Doclet: plug-in program for javadoc that formats and
outputs required documentation
• The javadoc tool
– Preprocesses doc comments into a data structure
– Delegates to a doclet conversion of data into output
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An index.html File Generated by
javadoc
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Packaging Programs for
Distribution
• The standard way to distribute J2SE is to
combine files into a Java archive file using
the jar tool
• Before running the jar tool, make sure your
files are in the proper folders
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Summary
• The Java 2 platform comes in three
versions: Java 2 Standard Edition (J2SE),
Java 2 Enterprise Edition (J2EE), and
Java2 Micro Edition (J2ME).
• You can write different kinds of programs
in Java including standalone applications,
applets, servlets and JSPs, JavaBeans
and Enterprise JavaBeans (EJBs).
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Summary (Cont.)
• Java is an object-oriented language and lends
itself to the creation of reusable components.
• Java language supports abstract data types,
encapsulation, inheritance, and polymorphism,
uses iterative and incremental methodology, and
implements design patterns.
• The SDK includes command line tools: the javac
compiler, java launcher, javadoc documentation
builder, and jar packaging utility.
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