And that’s how it’s done =)

I’ve finished my project… feels great. Got a lot of knowledge from it in JavaEE and I hope I will refine it soon. Question remain how do I access EJB in the JSP? Will try to use the same way that I did with Java Beans but looks like I failed because of database connectivity problems and not because of wrong methods. Any way feel much more confident in it.

A couple of days ago I came up with one dilemma: I asked myself how can I put a gradient on the page with HTML and CSS. The only solution that I found is to use gradient pattern (say 1px line witch present the actual gradient) and simply clone it with a CSS.
But I found today other good solution with HTML5.

The code in HTML is very simple:

Basically it is a normal rectangle.

Then you need to write the following javascript.

var d_canvas = document.getElementById(“d”);
var context = d_canvas.getContext(“2d”);
var my_gradient = context.createLinearGradient(0, 0, 300, 0);
my_gradient.addColorStop(0, “black”);
my_gradient.addColorStop(1, “white”);
context.fillStyle = my_gradient;
context.fillRect(0, 0, 300, 225);
What we’ve done is got the picture by id, assign the parameters and returned it back as a gradient.
I hope that was helpful, for more information check the website diveintohtml5.org, I’ve found it quite helpful and descriptive!

So I’ve spent a couple of hours looking such topics like “500 free tools for user design” etc. No I want to try Cacoo. As the official web site said, this tool is free and video showed that it’s quite convenient. I will post my experience some time later.

After some search was really upset because lots of web sites tries to promote Napkin feel&look but instead this program only gives the look of the mockups to the programs and windows. So for me it’s useless.

However, I found Mockingbird. It’s a web based tool for your mockups. Easy to use, free, with the ability to share with others simply by providing the link, saves as a PDF or PNG. I like the sticky edges, makes easier to create design. Must have tool!

Couple of issues for me are: not configurable interface and I found not that comfortable so scroll through all widgets (thanks for search and categories, without them it will be useless), inability to upload a picture and use it say for background.

The rest is fine! Check it!

What I’ve learned

I ‘ve learned how to implement EJB3 in my project. Let’s start from the beginning: the are 3 types of the EJB: Session Bean (Stateful, Stateless) which is used for business logic and state maintenance, Entity Bean which is used as a representation of the database object and Message-Driven Bean mainly used in asynchronous messaging environment.

In my assignment I will not use Message-Driven and Entity Beans (I don’t need first and second I’m going to replace with JPA), however, Session Beans are widely used. I came up with a question: how I’m going to implement my MVC model? The answer is obvious – for navigation is better to use Stateless beans because container allows to serve 100′s of clients with only one EJB what can give performance enhancement.

But I found other question: what if container itself requires resources such as memory and processing time? Maybe it would be better to implement the MVC without EBJ but normal Java Beans instead without the container? Probably this solution will give the better performance in case of 1000′s of users. Not sure about that so I will try to do a research or ask programmers from the industry.

After all, I have MVC skeleton ready! Work on design now, also I think about implementing the search by tag system… if I will have a time.

Issues

One big issue. I’ve created from the beginning the Enterprise Application in the NetBeans. Basically, it is the same Web Application + EJB Module but the addition is the Ant script which puts everything into one Enterprise Archive (EAR). Unfortunately, it’s sort of bug of the GlassFish server, after I execute the program, NetBeans can’t deploy my application on server. So I’ve spent half a day trying to find the solution, but almost without good results. One suggestion that I’ve found is the problem of interpretation of the localhost on my laptop. People say that if the address looks like 127.0.0.1/Application it works but not when localhost/Application. They say that in Vista this issue occurs because the host file contains :::1 localhost and the solution is to put standard loopback address.

I’ve checked my etc/hosts but everything was just fine. I believe the problem is in the GlassFish configuration. Anyway, I don’t want to spend my time on it anymore, so I just deleted the enterprise script and going to read how to assemble it manually later.

That’s all for today, stay with us.

Sorry for long delay in posting, I was too busy with my Project Management assignment.

So, last week we had extremely good tutorial about CSS2! Also I’m so impressed by HTML5 and going to spend more time on learning it. I’m not new in PHP and MySQL so today’s tutorial shouldn’t be a problem.

I want to share one good link with people who think that configuring Apache, php and MySQL/Postgre is a pain, here is nice WAMP package made by one crazy russian developer, called DENWER (short from Russian: web developers dgentlemen’s kit). This package is very easy to install and it provides you server+database from the scratch. Moreover, you can install it even on your USB stick!

Enjoy:

DENWER

The link is Tutorial, it’s only the first video from the 5.

The only issue that I’ve found is the auto-generated code that the lecturer uses: he type session and press auto-fill combination of buttons. His exact code is:

int count;

if (request.getSession().getAttribute(“count”) == null){ count = 0; }

else { count = (Integer) request.getSession().getAttrib­ute(“count”); }

request.getSession().setAttrib­ute(“count”, ++count);

out.println(“Accessed: ” + request.getSession().getAttrib­ute(“count”));

http://australianheadhunters.com/DMT/LearningProposal.html