Solved

Replacement for using instanceOf operator

Posted on 2006-06-28
5
669 Views
Last Modified: 2006-11-18
I am using the instanceof operator in the following manner:

      if (data instanceof ScoringActionData){
            ScoringActionData scoringActionData = (ScoringActionData)data;
            execute(scoringActionData);      
      } else if (data instanceof AggregationActionData){
            AggregationActionData aggregationActionData = (AggregationActionData)data;
            execute(aggregationActionData);
      }

Both the ScoringActionData and the AggregationActionData objects extend ActionDataImpl which in turn implements ActionData.

I would like to find a way to get away from using the instanceof operator, but haven't been able to find a suitable replacement.  I have looked in several places, but haven't been able to find anything. Does anyone have any ideas?  A code example would be appreciated.  Thanks.
0
Comment
Question by:jbcarrico
[X]
Welcome to Experts Exchange

Add your voice to the tech community where 5M+ people just like you are talking about what matters.

  • Help others & share knowledge
  • Earn cash & points
  • Learn & ask questions
  • 2
  • 2
5 Comments
 
LVL 10

Expert Comment

by:mukundha_expert
ID: 17003747
get the class name

for e.g,

String classname = data.getClass() . getName () ;

it will give the fully qualified name of the class ( including package )

if your data is of type Hashtable,
you will get java.util.HashTable in your classname.
0
 
LVL 10

Expert Comment

by:mukundha_expert
ID: 17003757
if you want only the class nam,

String className = c.getName() .substring( c.getName().lastIndexOf(".") + 1 ,c.getName() .length() ) ;

get the className and check for the condition using className.equals()
0
 

Author Comment

by:jbcarrico
ID: 17003858
Is there any way I can cause the code to branch to the appropriate  'execute()' method by using the superclass, ActionData or something like that?  What I'm trying to do is get away from any type of branching statement.  I want to implement something that will branch to the appropriate 'execute()' without casting the 'ActionData' object directly to a ScoringActionData or AggregationActionData object.  Can that be done?  I hope this is clear enough.  
0
 
LVL 16

Accepted Solution

by:
imladris earned 250 total points
ID: 17003892
I don't know the overall structure and requirements of what is going on.

If it's possible, the nicest way to deal with this would be to have the execute method be part of the ActionData or ActionDataImpl class. Any derived class could (or would have to if you made it abstract) override the execute method to provide functionality appropriate for its data.

Then the branches are simply replaced with:

data.execute();

0
 

Author Comment

by:jbcarrico
ID: 17003939
Thanks to both of you, mukunda_expert and imladris, for the great answers.  I did get the answer I was looking for, and I appreciate all of the effort you put into answering my question.
0

Featured Post

PeopleSoft Has Never Been Easier

PeopleSoft Adoption Made Smooth & Simple!

On-The-Job Training Is made Intuitive & Easy With WalkMe's On-Screen Guidance Tool.  Claim Your Free WalkMe Account Now

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

Go is an acronym of golang, is a programming language developed Google in 2007. Go is a new language that is mostly in the C family, with significant input from Pascal/Modula/Oberon family. Hence Go arisen as low-level language with fast compilation…
Java functions are among the best things for programmers to work with as Java sites can be very easy to read and prepare. Java especially simplifies many processes in the coding industry as it helps integrate many forms of technology and different d…
The viewer will learn how to implement Singleton Design Pattern in Java.
This tutorial explains how to use the VisualVM tool for the Java platform application. This video goes into detail on the Threads, Sampler, and Profiler tabs.

695 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question