when to use beans

pigsie · Jun 22, 2002

Hi

I am new to JSP and am trying to figure out when to use beans. Basically I have a system where i would like to have some objects held in ram but instead of using beans i can use objects is there any reason to use one method over the other? Does one perform better than the other?

Thanks

wushutwist · Jun 22, 2002

Are you referring to JavaBeans or Enterprise JavaBeans. A standard JavaBean is just a plain Java class with getter and setter methods. This definitely suffices for most web only applications.

joelmac · Jun 23, 2002

What would an Enterprise JavaBean be?? ________________________
JoelMac
ICQ#:48144432

pigsie · Jun 23, 2002

I was referring to java beans for a web application

I cant see any advantages to using beans
over classes are there any?

Thanks

jbruggeman · Jun 24, 2002

JavaBeans are just plain classes !!! jou only put some set and get methods in it to fill or read it's variables from your jsp.

As far as I know, Enterprise JavaBean (which came with J2EE) are classes that sit over a database connection, or maintain process information. You use them to get an extra level of structure (abstraction) in your application.

Kindon · Jun 24, 2002

Yeah. A JavaBean IS a class. It is a specialized class. If you follow the rules for making JavaBeans it will make your life easier that just making the class your way. It does things for you. Example JavaBean:

public class MyString {

String str1;

public void setStr1(String s){str1 = s;}
public void getStr1(String s) {return str1;}
}

Now in your JSP you can use this:

<html><body>
<jsp:useBean name="MyString1" class="MyString">
<jsp:setProperty name="MyString1" property="str1" value="I">
Here is my string: <jsp:getProperty name="MyString1" property="str1">
</body></html>

Notice that I never call the methods getStr1() or setStr1() in the JSP. How does it know which method to call? Simple. If you follow the pattern of making your metod names set + " capped variable name" or get + "capped variable name", the JSP will know what to do. It knows because you put in jsp:getProperty or jsp:setProperty. It puts two and two together for you. If you do not do this, things will get more difficult for you. Much more difficult. This is one advantage to creating a class in a JavaBean format.

Remember, a JavaBean IS a class. It is just a class that follows certain rules as to how it is written. Those rules help it do its specific role in a MVC environment.

Enjoy!

pigsie · Jun 24, 2002

Thanks for the reply. SO are you saying that the rules
of javabeans make it easier for a developer to know what methods are needed to set/get properties?

Also should beans be used to hold state information? for example if i have an application which has logged in users would it be better to use a bean to hold the user session info short term(given that it may be updated) or place a user object in the session scope?

thanks

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when to use beans

pigsie

Programmer

wushutwist

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joelmac

Programmer

pigsie

Programmer

jbruggeman

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Kindon

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pigsie

Programmer

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