A Simple EJB 3.0 Example With JSP and Servlet
January 14, 2011 8 Comments
Yesterday I was trying to begin with EJB. There are lots of resources in web, but I found very less for EJB 3.0 in Netbeans. Among all tutorials, a video in Utube was easy to follow and very effective for understanding. Just few changes was required for me, because that tutorial is in Netbeans 6.1 and I am using Netbeans 6.9.
Here are those steps that I followed for a Stateless Session Bean program to combine with JSP and Servlet.
File -> New Project -> Java EE -> EJB Module
Next, provide the Project Name
Select Webserver and J2EE version, Finish.
Right click on the Project -> New -> Session Bean..
Provide a Bean Name
Assign a Package Name
Select Session Type as Stateless
And set the Interface as Remote, Finish
Open SessionBean.java
Press <alt + insert>, From the list select Add Business Method
Provide Menthod Name
Define a Return Type
Add Parameter by clicking on Add Button
Change the given method body to following code.
@Stateless
public class SessionBean implements SessionBeanRemote {
public String businessMethod(String name) {
return "Welcome " + name;
}
}
Right Click on project and click on Build
Now the componenct is created and we have to use that component in Web Container. Here in this example we are going to use the EJB component via Servlet.
File -> New Project -> Java Web -> Web Application
Next, Provide Project Name
Next, Select Web Server and J2EE version, Finish.
Right Click on Web Pages -> New -> Servlet..
Provide Servlet Name and Package location
Next, Provide a URL pattern for the Servlet, Finish.
In Servlet Page, remove comment from processRequest method body.
Press <alt + insert>, From the list Select Call Interprise Bean
Go to index.jsp and create a form with a textbox and button and action to be use_ejb.do (servlet url pattern)
<%@page contentType="text/html" pageEncoding="UTF-8"%>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"
"http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>EJB Example</title>
</head>
<body>
<form action="use_ejb.do" method="post">
<input type="text" name="nm">
<input type="submit" value="OK">
</form>
</body>
</html>
Then go to Servlet and send the received value from textbox to the RemoteBean method to get result from the RemoteBean.
protected void processRequest(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
String str1=request.getParameter("nm");
String str2=sessionBean.businessMethod(str1);
response.setContentType("text/html;charset=UTF-8");
PrintWriter out = response.getWriter();
try {
out.println("<html>");
out.println("<head>");
out.println("<title>Servlet UseBean</title>");
out.println("</head>");
out.println("<body>");
out.println("<h1>" + str2 + "</h1>");
out.println("</body>");
out.println("</html>");
} finally {
out.close();
}
}
Output :
public class SessionBean implements SessionBeanRemote {
public String businessMethod(String name) {
return “Welcome ” + name;
}
}
Its very useful for Beginners…it toooo good…
It would be useful if there is such a demo program using stateful,msg driven etc..etc..
good
Its very useful.thanx a lot ….. need more examples
Its really a good example for beginner .. to knw the BIG term EJB
it is good guide.
but i have problem at picture #5, I cannot choose drop down list of Remote option
why?
I worked the same example with netbeans 6,9.1 ,i got this error after MyEJB has been successfully deployed….
In-place deployment at C:\Documents and Settings\student\My Documents\NetBeansProjects\WebEJBExample\build\web
deploy?path=C:\Documents and Settings\student\My Documents\NetBeansProjects\WebEJBExample\build\web&name=WebEJBExample&force=true failed on GlassFish v3
C:\Documents and Settings\student\My Documents\NetBeansProjects\WebEJBExample\nbproject\build-impl.xml:586: The module has not been deployed.
BUILD FAILED (total time: 0 seconds)
Pls anyone reply me for this problem……Thanks in advance
While Executing Im getting an error like GlassFish Server Failed, why? pls anyone help me