CODEWITHSUNDEEP
jspjavabeansrace-conditionstateless
JRR
JRR

Reputation: 6152

jsp and java beans

I am building jsp pages hosted on tomcat and am wondering if the bean instances referenced in each jsp are stateless / stateful? How do those bean instances come about? Are they (re-)created each time when the page is visited? Do I need to worry about two different users visiting the same page at the same time and getting hold of the same bean instance?

In general I find the interaction between jsp and beans quite confusing so I'd appreciate if someone can refer a tutorial / explanation of those concepts. Thanks!

P.S. How about static fields in the bean classes? Do those values have application scope by default?

Upvotes: 1

Views: 587

Answers (2)

ramsinb
ramsinb

Reputation: 2005

The life cycle of the bean is upto the developer or framework the developer choices to use. If you think about a request over multiple pages (or even the same page) unless after you create an instance of a class and store it somewhere then it will be stateless. This is where Java EE session management comes into place, so if you want stateful behavior you would create a instance of the bean and 'persist' it to the session.

If you do persist to a session you don't have to worry about multiple users hitting the application given a session is unique per user and Java EE tries to ensure this.

Upvotes: 0

KV Prajapati
KV Prajapati

Reputation: 94645

The bean is Plain Object Java Object and purpose behind development of bean is to store/persist data.

if the bean instances referenced in each jsp are stateless / stateful?

Stateless by default.

How do those bean instances come about? Are they (re-)created each time when the page is visited?

It depends upon the code you've used.

Do I need to worry about two different users visiting the same page at the same time and getting hold of the same bean instance?

Unless you've created a bean with application scope.

About JavaBeans and JSP

Upvotes: 3

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