Java Programming

[Background]
[Basics] (Hello World, IO, methods, types, arrays, objects, Inheritance, dynamic dispatch)
[More Java Features] (Interfaces, Exceptions, Swing GUIs, Applet, Collections, Graphics, Help API)
[GUI Builder] (tutorials using NetBeans)
[New features of Java 5]
[C++ / Java Comparison] (addresses, pointers, classes)

The assumption here is that you are already a proficient C/C++ programmer. Much of the information below is taken from Sun's Java tutorial site (indicated as sun.com). Other examples are taken from the CFX examples repository (indicated as CFX, see also a static version, or browse the examples directory). See the source code for the Horton Java book, or this local copy.

Background

Java is both a Language and a Platform (sun.com) (compiler, interpreter, jvm)
Java programs can be standalone applications, web-based applications, or web browser-based applets (see examples from sun.com)
As in C++, Java programs are made up of classes (CFX). (See illustration of creating classes using BlueJ)

Basics of the Language

These examples assume you already know a language such as C++. See Sun's introductory Java tutorial path.

• A basic program for Hello World (CFX)
• Input/Output (CFX) examples
• Calling Methods (CFX) examples, particular methods with reference parameters (CFX)
• Types (CFX)
• Arrays (CFX) in Java, Arraylist (CFX). Sun's arrays tutorial. Talha's arrays presentation (powerpoint).
  (Note: ArrayList is faster than the legacy class Vector, though Vector is well behaved when accessed concurrently from multiple threads (it is synchronized). ArrayList can be synchronized by wrapping it in Collections.SynchronizedList or Collections.synchronizedMap.)
• Java Objects (doc file, from Liskov notes)
• Inheritance explanation and examples, and mechanism used for Dynamic Dispatch (doc file)

More Java Features

• Interfaces explanation and examples. Examples in CFX. NoiseMaker example (CFX) shows how multiple classes can all implement the same method in an Interface.
• Exceptions motivation and mechanism, Issues (doc, based on Liskov's Lecture 11 notes (pdf))
• Swing GUI (Graphical User Interface) programming
• Applets examples: running your program in a browser
• Collections classes Framework (lists, sets, maps)
• Graphics examples to display geometric shapes and do simple animation
• Java Help API powerpoint by Paul Trzyna and Niral Shukla, Java Help jar files (zip)

GUI Builder

• NetBeans
  A NetBeans tutorial to concatentate strings.
  A simple tutorial on using the GUI Builder in NetBeans to make a "ColorSwitcher" application, another short tutorial.

New Features of Java 5

Sun has a description of new features in Java 5 (a.k.a. Java 1.5).

These features include generic types (like C++ templates), autoboxing (e.g. auto conversion to base types of objects stored in ArrayList), an enhanced for loop making it easier to iterate through Collections, enumerated types, static import, C style formatted input/output, and variable arguments.

On the CS lab machines, Java 5 is found at:
       /usr/java/jdk1.5.0/

Comparison of Java with C++

See this comparison that addresses, pointers, classes, and other differences.

[CS Dept.] [UIC] [Prof. Reed]