J2ee Hierarch

[Former Member]

I am a beginner with Java. Would some one just guide me in what Hierarchy I have to approach the J2EE from the following list

1) EJB 2) Servlets and 3) Web Service 4) J2ee 5) Core Java 6) JSP 7) Java Proxies

And also if you would tell me the Important areas I have to cover in the above list would be greatly appreicated.

I dont need any material or Blogs.

Thanks

[Former Member · Accepted solution]

Hi Jenni,

For beginners the best is to begin with Tomcat installation.You can configure and install Apache Tomcat 6.0 for use as standalone webserver.The basic steps that are required for running servlets are -

<i><b>1) Install JDK</b></i>

Your first step is to download and install Java. Tomcat 6.0 requires JDK 1.5 Standard Edition (Java 5) or JDK 1.6 Standard Edition (Java 6). See the following sites for download and installation information.

Once you've installed Java, confirm that everything including your PATH is configured properly by opening a DOS window and typing "java -version" and "javac -help".

<i><b>2) Configure Tomcat</b></i>

Go to http://tomcat.apache.org/download-60.cgi and download and unpack the zip file for the current release build of Tomcat 6. You specify the top-level directory (e.g., C:\) and the zip file has embedded subdirectories (e.g., apache-tomcat-6.0.10).

Next, you must set the JAVA_HOME environment variable to tell Tomcat where to find Java

<b>Enable the Invoker Servlet</b>

The invoker servlet lets you run servlets without first making changes to your Web application's deployment descriptor (i.e., the WEB-INF/web.xml file). Instead, you just drop your servlet into WEB-INF/classes and use the URL http://host/servlet/ServletName (or http://host/webAppName/servlet/ServletName once you start using your own Web applications.

<i><b>3) Setup Development Environment</b></i>

The server already knows about the servlet classes, but the compiler (i.e., javac) you use for development probably doesn't. So, if you don't set your CLASSPATH (either via an environment variable, an operating system setting, or an IDE setting), attempts to compile servlets, tag libraries, filters, Web app listeners, or other classes that use the servlet and JSP APIs will fail with error messages about unknown classes. Here are the standard Tomcat locations:

install_dir/common/lib/servlet-api.jar

install_dir/common/lib/jsp-api.jar

You need to include both files in your CLASSPATH.

<i><b>4) Test Server</b></i>

Before trying your own servlets or JSP pages, you should make sure that the server is installed and configured properly. For Tomcat, click on install_dir/bin/startup.bat (or execute install_dir/bin/startup.sh on Unix/Linux). Next, enter the URL http://localhost/ in your browser and make sure you get the Tomcat welcome page, not an error message saying that the page could not be displayed or that the server could not be found.

The steps mentioned here are explained in DETAIL in the following document

http://www.coreservlets.com/Apache-Tomcat-Tutorial/

[Former Member · Accepted solution]

Thank you Friends. I really appreciate all your advises and suggestions.

[former_member186016 · Accepted solution]

Something very useful to you:

http://www.eclipse.org/webtools/community/tutorials/BuildJ2EEWebApp/BuildJ2EEWebApp.html

Regards,

Ashwani kr Sharma

[Former Member]

Hi,

I would suggest first be strong in core java and then move towards servlets and JSP and then to EJB, Webservices.

Having good skills in core java is a must.

regards

Vivek Nidhi

[former_member186016]

You should do in following order:

5->2->6->1->3->7 J2EE will be covered in this process.

You should be good in core java. And then 2,6,1 are mandatory.

Regards,

Ashwani Kr Sharma

[Former Member]

Thanks Ashwani. I belive this is the order you are recommending me, sure I will follow that.

1) Core Java 2) Servlets 3) JSP 4) EJB 5) Web Service 6) Java proxies

Now coming to Servlets , if I want to install the necessary components , where can I download and if there is any guide that will give step by step procedure to do that?

Thanks.

[former_member186016]

For working with servlets, you need a App/Web Server with Servlet container.

You can download SAP AS, or even JBoss.

JBoss is freely available and SAP AS has trial version available freely.

This might be useful for you while doing installation for JBoss:

http://www.purposesolutions.com/Resources/EclipseJ2EE.html

http://today.java.net/pub/a/today/2005/03/01/InstallingJBoss.html

And then start working on it.

Regards,

Ashwani Kr Sharma

[Former Member]

I would recommend using Tomcat, for reasons of being freely available, a lightweight download (max 50 MB) and you need not know tweaky administrative stuff....using WebAS for learning servelets would be overkill...