Difference between simple beans and EJB

Anybody knows... the difference between the simple beans and EJB... Pls share with all. thanks a lot.

The Verrrrrrrrry short scoop is that JavaBeans pretty much just adhere to a standard format, mostly getters and setters. EJBs work only within a specific framework - an EJB container, and have access to J2EE support. For a detailed look at EJBs, see my tutorial Getting Started with Enterprise JavaBeans Technology at the developerWorks Java zone:
http://www-106.ibm.com/developerworks/edu/j-dw-java-gsejb-i.html
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Similar Messages

What is the difference between Java Beans and EJBs ?

Hi,
Can someone tell me that ? Kind of confused... Thanks !
Philip

Hmm, I'm gonna have a go at this - hopefully someone will build on it with more differences or requirements:
A Java Bean is merely a Java class written to conform to some simply rules for construction and method naming eg:
public class MyBean
private String myField;
public MyBean()
public void setMyField(String myField)
this.myField = myField;
public String getMyField()
return myField;
}Applications can use Java Beans without having to know about the class in advance - a typical situation might be their use in visual GUI editors where the properties of the bean can be exposed and manipulated by the editor through examination of the method names or an accompanying descriptor.
An Enterprise Java Bean doesn't have all that much in common with a Java Bean. An EJB is a small set of classes meeting a single (usually) business requirement written to conform to the EJB specification. This enables them to be used by J2EE Application servers to perform enterprise business functions (data storage, manipulation, business logic etc.). The whole idea is that by writing to the specification the server can automatically provide support for transaction management, concurrent access, scaleability, etc that a mission-critical system might require without the programmer having to understand the workings of the application server.
Essentially an EJB can either
1) maintain the permanent state of a business object (eg, hold the data for a single product in a catalogue)
2) perform a small set of business operations (eg, place an order for a customer)
3) act in response to messages passed around the system (eg, send a mail to the user when the items have been shipped)
I would have a look at the following two pages to get a better overview:
http://java.sun.com/products/javabeans/
http://java.sun.com/products/ejb/
Hope this helps.

What is difference between Managed Bean and Backing Bean?

What is difference between Managed Bean and Backing Bean? Please guide me how to create them and when to use them?
Please post sample for both beans.

Hi,
managed beans and backing beans are quite the same in that the Java object is managed by the JavaServer Faces framework. Manage in this respect means instantiation. The difference is that backing beans contain component "binding" references, which managed beans usually don't. Do backing beans are page specific versions of managed beans.
Managed beans are configured either in the faces-config.xml file, or using ADF Faces and ADFc, in the adfc-config.xml file
Frank
Edited by: Frank Nimphius on Jan 31, 2011 8:49 AM

Question about main difference between Java bean and Java class in JSP

Hi All,
I am new to Java Bean and wonder what is the main difference to use a Bean or an Object in the jsp. I have search on the forum and find some post also asking the question but still answer my doubt. Indeed, what is the real advantage of using bean in jsp.
Let me give an example to illustrate my question:
<code>
<%@ page errorPage="errorpage.jsp" %>
<%@ page import="ShoppingCart" %>

<jsp:useBean id="cart" scope="session" class="ShoppingCart" />
<html>
<head><title>Shopping Cart</title></head>
<body bgcolor="#FFFFFF">
Your cart's ID is: <%=cart.getId()%>.
</body>
<html>
</code>
In the above code, I can also create a object of ShoppingCart by new operator then get the id at the following way.
<code>
<%
ShoppingCart cart = new ShoppingCart();
out.println(cart.getId());
%>
</code>
Now my question is what is the difference between the two method? As in my mind, a normal class can also have it setter and getter methods for its properties. But someone may say that, there is a scope="session", which can be declared in an normal object. It may be a point but it can be easily solved but putting the object in session by "session.setAttribute("cart", cart)".
I have been searching on this issue on the internet for a long time and most of them just say someting like "persistance of state", "bean follow some conventions of naming", "bean must implement ser" and so on. All of above can be solved by other means, for example, a normal class can also follow the convention. I am really get confused with it, and really want to know what is the main point(s) of using the java bean.
Any help will be highly apprecaited. Thanks!!!
Best Regards,
Alex

Hi All,
I am new to Java Bean and wonder what is the main
difference to use a Bean or an Object in the jsp. The first thing to realize is that JavaBeans are just Plain Old Java Objects (POJOs) that follow a specific set of semantics (get/set methods, etc...). So what is the difference between a Bean and an Object? Nothing.
<jsp:useBean id="cart" scope="session" class="ShoppingCart" />
In the above code, I can also create a object of
ShoppingCart by new operator then get the id at the
following way.
ShoppingCart cart = new ShoppingCart();
out.println(cart.getId());
...Sure you could. And if the Cart was in a package (it has to be) you also need to put an import statement in. Oh, and to make sure the object is accessable in the same scope, you have to put it into the PageContext scope. And to totally equal, you first check to see if that object already exists in scope. So to get the equivalant of this:
<jsp:useBean id="cart" class="my.pack.ShoppingCart"/>Then your scriptlet looks like this:
<%@ page import="my.pack.ShoppingCart %>
<%
ShoppingCart cart = pageContext.getAttribute("cart");
if (cart == null) {
    cart = new ShoppingCart();
    pageContext.setAttribute("cart", cart);
%>So it is a lot more work.
As in my mind, a normal class can also
have it setter and getter methods for its properties.True ... See below.
But someone may say that, there is a scope="session",
which can be declared in an normal object.As long as the object is serializeable, yes.
It may be
a point but it can be easily solved but putting the
object in session by "session.setAttribute("cart",
cart)".Possible, but if the object isn't serializable it can be unsafe. As the point I mentioned above, the useBean tag allows you to check if the bean exists already, and use that, or make a new one if it does not yet exist in one line. A lot easier than the code you need to use otherwise.
I have been searching on this issue on the internet
for a long time and most of them just say someting
like "persistance of state", "bean follow some
conventions of naming", "bean must implement ser" and
so on. Right, that would go along the lines of the definition of what a JavaBean is.
All of above can be solved by other means, for
example, a normal class can also follow the
convention. And if it does - then it is a JavaBean! A JavaBean is any Object whose class definition would include all of the following:
1) A public, no-argument constructor
2) Implements Serializeable
3) Properties are revealed through public mutator methods (void return type, start with 'set' have a single Object parameter list) and public accessor methods (Object return type, void parameter list, begin with 'get').
4) Contain any necessary event handling methods. Depending on the purpose of the bean, you may include event handlers for when the properties change.
I am really get confused with it, and
really want to know what is the main point(s) of
using the java bean.JavaBeans are normal objects that follow these conventions. Because they do, then you can access them through simplified means. For example, One way of having an object in session that contains data I want to print our might be:
<%@ page import="my.pack.ShoppingCart %>
<%
ShoppingCart cart = session.getAttribute("cart");
if (cart == null) {
    cart = new ShoppingCart();
    session.setAttribute("cart", cart);
%>Then later where I want to print a total:
<% out.print(cart.getTotal() %>Or, if the cart is a JavaBean I could do this:
<jsp:useBean id="cart" class="my.pack.ShoppingCart" scope="session"/>
Then later on:
<jsp:getProperty name="cart" property="total"/>
Or perhaps I want to set some properties on the object that I get off of the URL's parameter group. I could do this:
<%
ShoppingCart cart = session.getAttribute("cart");
if (cart == null) {
    cart = new ShoppingCart();
    cart.setCreditCard(request.getParameter("creditCard"));
    cart.setFirstName(request.getParameter("firstName"));
    cart.setLastName(request.getParameter("lastName"));
    cart.setBillingAddress1(request.getParameter("billingAddress1"));
    cart.setBillingAddress2(request.getParameter("billingAddress2"));
    cart.setZipCode(request.getParameter("zipCode"));
    cart.setRegion(request.getParameter("region"));
    cart.setCountry(request.getParameter("country"));
    pageContext.setAttribute("cart", cart);
    session.setAttribute("cart", cart);
}Or you could use:
<jsp:useBean id="cart" class="my.pack.ShoppingCart" scope="session">
<jsp:setProperty name="cart" property="*"/>
</jsp:useBean>The second seems easier to me.
It also allows you to use your objects in more varied cases - for example, JSTL (the standard tag libraries) and EL (expression language) only work with JavaBeans (objects that follow the JavaBeans conventions) because they expect objects to have the no-arg constuctor, and properties accessed/changed via getXXX and setXXX methods.
>
Any help will be highly apprecaited. Thanks!!!
Best Regards,
Alex

Difference between Simple maintanence and Export mode and Organisation plan

Hi all,
Can any one please explain the difference between Simple maintanence and Export mode and organisational plan in SAP easy access.
Thanks & Regards,
Naga

Expert Mode Infotype Maintenance: This interfaces allows you to edit individually selected objects in OM (Org Units, Positions, Jobs) via infotypes.
Expert Mode: Simple Maintenance Interface (PPOM_OLD) is used to quickly create a new Organizational Plan. As a user, you can pretty much maintain large volumes of data very easily ( i.e create several objects simultaneously), without having to go through the more "Performance Intensive" Org and Staffing interface.
In accessing the Simple Maintenance interface to create your org structure, the initial screen requires you to specify which evaluation path you want to create your org structure.
Organizational Plan: This is what provides you with a complete picture of an enterprise's environment. It comprises elements (objects like Org Units, Positions, Jobs etc) which are used as building blocks for creating an Organizational structure.
Need more information? Let me know.

Differences between ejb2.0 and ejb 3.0

hi,
Can anybody tell me the differences between ejb2.0 and ejb3.0?
Thanks
Karimulla

http://www.theserverside.com/articles/article.tss?l=MonsonHaefel-Column1

The differents between Java Beans and Enterprise Java Beans

Please help me!
What is the differents between JavaBeans and Enterprise Java Beans (EJB) ?
Thank's for your answer

Enterprise Java Beans are special type of java beans.
EJBs invented to be used via remote VMs or remote computer
systems.They must be deployed on server to become accesible for remote
clients.

Difference between business components and EJB

hello guys, do anyone knows what is the core difference of using ADF Business components and EJB Session Beans ??

this blog might help http://blog.whitehorses.nl/2012/03/26/adf-11g-bc4j-or-ejb3/
Timo

Is there any difference between java Beans and general class library?

Hello,
I know a Java Bean is just a java object. But also a general class instance is also a java object. So can you tell me difference between a java bean and a general class instance? Or are the two just the same?
I assume a certain class is ("abc.class")
Second question is is it correct that we must only use the tag <jsp:useBean id="obj" class="abc.class" scope="page" /> when we are writng jsp program which engage in using a class?Any other way to use a class( create object)? such as use the java keyword "new" inside jsp program?
JohnWen604
19-July-2005

a bean is a Java class, but a Java class does not have to be a bean. In other words a bean in a specific Java class and has rules that have to be followed before you have a bean--like a no argument constructor. There are many other features of beans that you may implement if you so choose, but read over the bean tutorial and you'll see, there is a lot to a bean that is just not there for many of the Java classes.
Second question: I'll defer to someone else, I do way to little JSP's to be able to say "must only[\b]".

Difference between BI Beans and olap api

HI
is there anyone can tell me the difference between
BI and olap api ,
is BI a language or components ,why
when i build crosstab with BI beans it uses classes
different from olap pi classes (oracle.dss.*)
and olap api (oracle.express.*)
so BI is another language independent of olap api
or it uses olap api to connect to OLAP
BI works , OLAP api doesn't work
thanks

Hi,
This is a great question. The OLAP API is an Oracle published Java API for access to Oracle OLAP. This exposes the OLAP cube/dimension model via Java. The OLAP API documentation can be found on the OLAP secion of OTN, see the link on the BI Beans section of OTN. Within the documention section there is a link to the acle9i OLAP Release 2 - Developer's Guide to the OLAP API:
http://otn.oracle.com/products/bi/pdf/OLAPIguide.pdf
Customers can write their own Java code directly against this public API to display and manage OLAP objects. The OLAP API documentation explains how to do this.
As users typically will want to present OLAP data in either a crosstab and/or graph Oracle created a pre-packaged set of components to help customers to quickly and easily create powerful OLAP applications. BI Beans are a set of fully J2EE compliant java beans that provide major components such as:
- presentation beans (graph/crosstab/table)
- OLAP beans
- catalog services beans
These components have extensive APIs to allow developers to comprehensively customize an application, both Java client and thin client (HTML/JSP and UIX).
By default BI Beans connect to an Oracle database using the OLAP API as a primary data source (although users can create their own non-OLAP data sources). This allows developers and end-users to directly access dimensions and measures created to the OLAP specification.
This is explained in more detail in the Oracle BI Beans Technical Whitepaper:
http://otn.oracle.com/products/bib/htdocs/collateral/bi_beans_white_paper.pdf
Hope this helps
Business Intelligence Beans Product Management Team
Oracle Corporation

Difference Between java bean And POJO

Hi,
What is the difference between the POJO the plain old javaobject and java bean ,
in my sense what is the basic difference between POJO and the object of a java bean class
Thanks
Arun

http://en.wikipedia.org/wiki/POJO
http://java.sun.com/products/javabeans/

Difference between BI beans and Oracle Discoverer

My understanding is that
BI beans and Discoverer are used for displaying data in tables, crosstab reports and graphs, Discoverer is meant for end users and BI beans is meant for use within a Java application.
Please let me know if my understanding is correct.

Hi
You are quite right.
If put in simple language Disc. Reports are just the outcomes of the Repotiing Tool and BIBeans is just a
component that can be used through Jdeveloper that
allows us to create various reports on the OLAP database objects.
Happy Working.

Diff between java beans and EJB

What is Java Bean

http://www.google.co.uk/search?hl=en&q=What+is+Java+Bean&btnG=Google+Search&meta=

Difference between Java class and JavaBean?

What is the difference between a Java class and a JavaBean?
A class has variables which hold state.
A class has methods which can do things (like change state).
And if I understand a JavaBean it is rather like a BIG class...
i.e.
A JavaBean has variables which hold state.
A JavaBean has methods which can do things (like change state).
So, what's the difference between the two?
And in case it helps...What is the crossover point between the two? Is there a minimalist type JavaBean which is the same as a class? What is the difference between Java beans and Enterprise Java Beans?
Thanks.

Introspection, as I understand it is a bunch of
methods which allows me to ask what a class can do
etc. right? So, if I implement a bunch of
introspection methods for my class then my class
becomes a JavaBean?Introspection allows a builder tool to discover a Bean's properties, methods, and events, either by:
Following design patterns when naming Bean features which the Introspector class examines for these design patterns to discover Bean features.
By explicitly providing the information with a related Bean Information class (which implements the BeanInfo interface).
I understand now they are completely different.
Thanks. Very clear.
I do not understand how they are completely different.
In fact I don't have a clue what the differences are
other than to quote what you have written. In your
own words, what is the difference? This is the "New
to Java Technology" forum ;-) and I'm new to these
things.In that case ejbs are way too advanced for you, so don't worry about it.

Difference between connection pooling and simple connection

Anybody please tell me what is the Difference between connection pooling and simple connection and also where we define connection pooling and how.
Thanks
Please reply soon
amitindia

Creating and closing connection to the database is a relatively slow process. Equally connections use database resources so you can't just open as many as you want.
A connection pool maintains a number of open connections throughout the lifetime of the application. Instead of opening and closing the connections your application just "borrows" them from the pool when they're needed.
If the pool runs out of connections it will usually create new ones as needed until you reach some predefined upper limit.
A good connection pool will also manage connections which have failed for any reason, and report code which fails to return connections to the pool (ie connection leaks).
The number of connections created at startup is referred to as the "low water mark" and the maximum number that the pool will allow to be opened at any given time is the "high water mark". If no connections are available client code will generally block until one is released.
If by "defined" you mean where can you get a working implementation then your database or application server vendor is likely to provide one. Also the Apache Jakarta Commons includes [url http://jakarta.apache.org/commons/dbcp/]an implementation which you can use with any JDBC driver.
Dave.

Difference between simple beans and EJB

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