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abstract classes

Andrew Lit
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Joined: Jul 01, 2002
Posts: 135
where could i read about usage of abstract classes? i couldn't find nothing suitable for me on java.sun.com.
could you suggest me something?
thanx
Cindy Glass
"The Hood"
Sheriff

Joined: Sep 29, 2000
Posts: 8521
If you do a google search on this site for +abstract+class you will find alot of reading material on the subject.


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Andrew Lit
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Joined: Jul 01, 2002
Posts: 135
of course i will but i thought that someone could suggest something here
but thanx anyway
Dan Chisholm
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Joined: Jul 02, 2002
Posts: 1865
The Java Language Specification has a good description of abstract classes and how to use them.
Java Language Specification section 8.1.1.1, Abstract Classes
[ July 24, 2002: Message edited by: Dan Chisholm ]

Dan Chisholm<br />SCJP 1.4<br /> <br /><a href="http://www.danchisholm.net/" target="_blank" rel="nofollow">Try my mock exam.</a>
Anthony Villanueva
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Joined: Mar 22, 2002
Posts: 1055
Basically, an abstract class is a class that cannot be instantiated. If you like, you can treat it as an interface. An abstract class is normally expected to be subclassed and its methods overriden/implemented by this subclass.
It doesn't matter if the abstract class has abstract methods or not. You can have an abstract with all of its methods implemented. However, a class that implements an interface or extends an abstract class, and does not implement all of superclass's methods, must be declared as an abstract class.
Snigdha Solanki
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Joined: Sep 07, 2000
Posts: 128
From the Java API, jav.io.InputStream is an abstract class.It is the superclass of all classes representing an input stream of bytes.
InputStream has the following abstract method:
public abstract int read();
which a subclass must provide an implementation for.Some of the subclasses of InputStream are FileInputStream,ByteArrayInputStream and FilterInputStream.


Snigdha<br />Sun Certified Programmer for the Java™ 2 Platform
Andrew Lit
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Joined: Jul 01, 2002
Posts: 135
thank you very much
 
I agree. Here's the link: http://aspose.com/file-tools
 
subject: abstract classes