by Mary Campione
This trail covers the fundamentals of programming
in the Java language including discussions of several of the core classes
shipped with the Java environment. Like the rest of the tutorial, the Java
trail was designed so that you can skip around. As Java has many similarities
with C and C++, if you are an experienced C or C++ programmer, you may want to
skim the first few lessons to orient yourself to Java then dive into the later
lessons as you are interested in them. Also, feel free to jump to other trails
in the tutorial as you see fit. The lessons in other trails will provide links
to any lessons in this trail if they contain pre-requisite information.
The book version of this tutorial breaks this trail in two:
Writing Java Programs
Object-Oriented Programming Concepts: A Primer
cuts through the hype surrounding object-oriented technology and teaches you
its core concepts: objects, messages, classes, and inheritance. It's important to
understand these key concepts before delving into the specifics of the Java language.
This lesson also contains a bibliography for further reading on the subject.
Feel free to skip this lesson if you are already familiar with
object-oriented programming.
The Nuts and Bolts of the Java Language
introduces you to several components of the Java language
by explaining a simple Java application line by line. You will learn
about the syntax and semantics of the Java language, plus several features
of the Java programming environment.
Because Java's syntax is similar to that of other programming languages, particularly
C and C++, much of this material will be familiar to seasoned programmers. You may wish
to skim this lesson for its main points and use it as a reference source.
Objects, Classes, and Interfaces
takes the concepts you learned in the first lesson of this trail
and shows you how to make use of those concepts in the Java language. You will
learn how to create, use, and destroy objects, how to write your own classes, including information
about writing methods and creating subclasses, and how to create and use
interfaces. And finally, this lesson shows you how to manage your classes and interfaces
within packages. This lesson is a complete do-it-yourself "Object-Oriented Programming in Java" lesson.
Again, programmers experienced in other object-oriented languages may wish
to skim this lesson and use it later as a reference source.
Using the Core Java Classes
The String and StringBuffer Classes
illustrates how to manipulate character data using
the String and StringBuffer classes. Through this lesson you will
also learn about accessor methods and how the compiler uses Strings and
StringBuffers behind the scenes.
Setting Program Attributes
describes how you can set attributes for your Java programs through
the use of properties and command line arguments. Use properties to
change attributes for every invocation of your program; use command-line
arguments to change attributes for only the current invocation of your program.
Using System Resources
shows you how your Java programs can access system resources (such as standard I/O,
array copying, and property management) through the
System class. The System class provides a system-independent programming interface
to system resources, allowing your programs to use them without compromising portability.
Handling Errors using Exceptions
explains how you can use Java's exception mechanism to handle
errors in your programs. In this lesson you will learn what an exception is,
how to throw and catch exceptions, what to do with an exception once you've
caught it, and how to best use the exception class hierarchy provided by the
Java development environment.
Threads of Control
discusses in detail the use of threads that enable your Java
applications or applets to perform multiple tasks at
the same time. This lesson describes when and why you might
want to use threads, shows you how to create and manage threads
and thread groups in your Java program, and shows you how to
avoid common pitfalls such as deadlock and race conditions.
Input and Output Streams
begins with a description of your likely first encounter with Java input and output
(I/O) streams. Then this lesson provides an overview of the InputStream
and OutputStream
family of classes. From there, this lesson provides many examples of how you to use the
most popular I/O streams, including two examples on how to write your own filtered
streams.
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