My first Wicket Web Application

There are many frameworks available today for creating dynamic web applications, some of which are extremely complicated and hard to use. Wicket is one of the few, easy to use tools out there that works well with Java programming. What makes Wicket different from most other web application tools is that it effectively separates the logic of the actual program from the simple HTML markup of a web page.

This week I set out to learn how to use Wicket in order to create a small web application for a simple stack Java program. With this program, a user can push items onto a stack, pop items from a stack, as well as clear the entire stack. Although the functionality of the program was quite simple, creating a web application for it did turn out to be more of a challenge.

Final Distribution Package for the Web App: stack-wicket-wolfft-1.0.1123.zip

final view of the stack web application

THE DEVELOPMENT PROCESS:

After reading some of the chapters of Wicket in Action as well as reviewing some actual examples provided by Dr. Johnson,  I started to grasp some of the basic principles of using Wicket. To my surprise creating an HTML page to interface a Java program is an extremely easy and clean process. Since there is no logic in the markup, the HTML page is left as simple as possible, and can be stylized and viewed all on its own.

On the other hand, creating a Java application that works with this HTML page is a bit more complicated. I wanted to create a stack application that would employ the use of forms, basic text output, as well as table output. In addition, I wanted to give each user of the application their own session in order to store their personal stack object and data. Luckily with Wicket, this task was not too daunting either. 

To do it all, I had to create an application class, then a page class, and then finally a sessions class. All of these components essentially run together to create the stack web application. Creating the page class was probably the most challenging out of all the classes since all sorts of different HTML elements were being updated on the one page at once. 

Another thing worth mentioning is the applications use of Jetty, a web server implementation that enables Java applications to run on a server. This was used to create a fully-working web application, though I more or less just reused code to get it to run.

DEVELOPMENT PROBLEMS:

I had a good time creating this stack application. I get real satisfaction from creating something that anyone can go out and use without having to run through a console. However, I did run into some small problems while developing it all. For one I had to figure out how to alert the user when they were trying to pop an empty stack. I fixed this by creating an error response text field in the page that would alert the user if they were popping an empty stack. Something else I could have done with this was only make the pop button visible when there were items in the stack.

Something else that I ran into was that initially the stack was presented in the table in list form, not stack form. This means the first item pushed was always the top item in the table. The way I like to thing of stack is the opposite of this and I wanted to make that clear on the page. I ended up creating a method in the Stack class that would put the stack in the right visual order right before updating the data to to table. It worked out quite nicely.

Also, one of the funny errors I kept getting was from CheckStyle on the basic Stack package classes. It simply stated:

Got an exception - java.lang.RuntimeException: Unable to get class information for @throws tag 'EmptyStackException'.

This was extremely confusing because I did not even alter the classes that the error was from. I was really stumped with this one and searched all over to try and figure it out. The problem ended up stemming from the build.xml file, which was not compiling all the classes, namely the EmptyStackException class. It was something small that I missed and when it was fixed it all worked nicely together.

LESSONS LEARNED

Creating this simple web app was more challenging than I initially anticipated. I spent a lot of time looking at the Wicket examples, trying to figure out the best way to create the application page, and still it wasn't working for me. Yet, now that it is all done, I feel I have a fairly good understanding of the Wicket framework. All the work spent on figuring out different ways to do things resulted in more knowledge of how things work. I do feel comfortable with Wicket and I know I will be using it in the future to create even more extensive web applications.

ICS Industry Day at UH Manoa

Today was the ICS Industry day at UH Manoa, an event I've been waiting to go to for awhile now. High tech companies from all over Hawaii come in and do presentations on what their company does, while showing some of the real life jobs that are available to a newly graduated student. Since I am a senior computer science student, I was extremely interested in seeing these presentations. I was also interested into seeing what sort of internships are available currently. Sadly though, I was not able to stay the entire time due to a 12:00 class I had (which I left early in order to get back to the presentations). 

All in all I was able to see the following presentations:

• Oceanit - A company based on Oahu, Kauai, and Maui that works on a wide range of 'innovative' projects for the government. They do a lot of Research and Development work.
• Alion Science - A larger company that also does a wide range of things, including software modeling for the military. 
• Concentris Systems - A company whose primary focus is on developing technology for the military. They developed the 'Indestructible Instant Network' system.

I have to say that I was really impressed by all the presentations. Growing up in Hawaii but traveling around the world, I never really saw Hawaii as an innovative place with high standards. However these companies are doing really innovative things! And in Hawaii nonetheless! It was really cool for me to see this.

OCEANIT

The Software Manager of Oceanit, Scott Libert, was an extremely friendly fellow. Even before the presentations had begun he had introduced himself and was telling me about what they do at the company, as well as what types of internships they have, etc. I learned that Oceanit likes to be on, as Scott put it, 'the bleeding edge,' constantly pushing the limits of technology. They've done some really cool stuff there, like use nano technology to make building structures more robust, as well as create technology that can check and see if people are in a building before entering (for military usage). It's really cool stuff to say the least. 

After Scott did his presentation, I went and had a talk with him about their internship they have for the summer. He was really nice about everything and gave me a bunch of information on what the interns do, as well as how to go about getting the internship. What's nice about their internship is its project based, so at the start you are given some project which you complete over the course of the internship. A recent intern just developed an iPhone application for the company. 

ALION SCIENCE

This was a pretty fun presentation put on by two guys who work for the company in Hawaii. They basically work on making simulations for the military, sort of like video games. What was great about their presentation was that they presented some of the facts about working as a software developer in the real world. I believe one of them stated that "you spend 80% of your time looking at other people's code or old code, rather than creating your own." He was making a point about how having good documentation is essential. They also mentioned a lot of the things we use in ICS413 like SVN, Continuous Integration, and JUnit. It felt pretty good to know all about those things and they stressed how important these technologies are to any project.

CONCENTRIS SYSTEMS

After initially leaving the presentations and going to my math class, I found myself extremely uninterested in what was going on, so I decided to pack up and go see some more presentations. I really wanted to see the Ikayzo (makers of techhui.com) presentation but I was too late. What I did get to see though was the presentation by Concentris Systems, which develops wireless technology primarily for the military. The presenter seemed really informed on just about everything and it was nice to actually see some of their physical technology there (he brought in a portable network module).

Concentris does some really cool stuff with their Indestructible Instant Network devices. What this basically does is set up network nodes on these little portable modules, which then all connect automatically in the most efficient way possible, thus enabling solid communication. What makes it indestructible is the fact that if one node goes down, the network is still in tact and running. Very cool stuff. They've developed all sorts of things that can use this technology, like land mine robots, or submarine docking communication. I was really surprised to see their plans for the future which were really large. For instance, with their network nodes, they are creating a user interface that links up to google earth and displays exactly where each node is on a map. This is integral for military units.

FINAL THOUGHTS

Overall I realized that there are in fact some really great technology companies in Hawaii that I could definitely see myself working at in the future. I've always planned on doing the big mainland move to get work elsewhere. However, there is a lot of stuff going on here now. Its really great for Hawaii. It's also good to see that these companies are still hiring workers all the time in light of the current state of the economy. I would recommend all ICS students go to presentations like this.

The Release of Due Dates Version 1.2 [team gold]

This week marks the release of Due Dates version 1.2 [Project Homepage]. With this new version comes two new features: an email reporting service, as well as a timer-based reporting function that allows the user to automatically have the program run at some specified interval of time. Both functions have been integrated into the Team Gold release of Due Dates and everything functions well.

This release also builds upon many fundamental changes to the source code. Classes have been stripped down and simplified. More checks have been added to ensure program robustness and a more exhaustive test suite has been created with well over 90% coverage. Due Dates v1.2 is definitely an upgrade from Due Dates v1.1.

GROUP PROCESS

This weeks development process was much the same as it has been the past few weeks. Although I had time to meet up, Scheller was really busy and so we were only able to meet up a couple times. Otherwise, we communicated via email, IM, or phone. Initially, we talked over program design and test design. We set up a bunch of issues that we thought would be the most useful in modifying the system. This was all good.

However, I found that Scheller and I have two different development styles. I like to get started on things early and he does stuff later. This can be attributed to Schellers heavy workload, but it really is hard to collaborate efficiently like this. Most of the time I felt like I was working alone on the project. I would just keep him updated with what was going on. Scheller did create some good code for the project though. He implemented the self-timer for running Due Dates on a schedule. 

Overall, the development of Due Dates v1.2 could have been better if Scheller and I had worked similarly on the project. Although the state of project meets my initially expectations for the program, things could have been done more efficiently. I would still like to meet up more in person, or at least communicate more on all things relating to the program. Hopefully on the next version of Due Dates, this can happen.

DEVELOPMENT

Development for Due Dates v1.2 went really great for me this week. I attribute this solely to starting early. I did not have to rush on anything the entire week, and I was able to really think out my ideas for the system. I felt like I was ahead most of the time which is not a usual thing for me. I hope to keep up this sort of development style with future developments of Due Dates.

DEVELOPMENT PROBLEMS 

The biggest problem we had in the development of this release was trying to get the DueDates.jar file to run correctly. The reason it was so challenging was because the program now uses JavaMail, and referencing these libraries is quite different than most libraries. They must be put directly in the system frameworks rather than referenced in the build classpath. It was especially confusing for me since my computer runs on soylatte 1.6 for its Java JRE, not the usual Java release.

Initially I had a lot of help from other students like Arthur Shum and Ronn Reeves. At one point, Arthur and I did a screen sharing thing through a messenger program called iChat, which allows him to control my computer. That was cool but it did not solve anything. We were copying the mail.jar file to the lib/ext of my Java framework, the right thing to do. However, it was still not working. 

Eventually I realized the only difference between my computer and Arthur's computer was that I was using soylatte. Thus it had to be a problem with that. Then it dawned on me (with the help of Arthur and Ronn). Instead of having the mail.java file in the system framework directory, I needed to put it in the soylatte directory on my system. This simple change fixed it all and the jar file ran fine after that. I was really stumped by this whole problem. I'm really glad it was eventually sorted out.

CONTINUOUS INTEGRATION AND SOFTWARE ICU

The development of Due Dates v1.2 was monitored by HackyStat, a software ICU program reviewed in my last blog post, In the Green With HackyStat. Essentially what this does is monitor all the vital signs of your program as well as monitor the development process. Due Dates had sensors sending data to HackyStat throughout the last week and it was great to visit the project page and see the results of this. It was nice to see current values and trends having to do with things like complexity, coupling, coverage, tests, development time, etc. I usually checked it a few times a day, just to see. I am happy to say Due Dates v1.2 is still all green.

What was cool about all this was that the Hudson continuous integration server ran a daily build that would send sensors back to the HackyStat sensorbase. This meant there was an automated build each day just for the software ICU. It was great to have the Hudson server do this.

FUTURE DUE DATES IDEAS

With Due Dates v1.2 there were a lot of improvements in functionality and there were many improvements in the source code. I am very satisfied with how it turned out. Yet, I know this program can be made even better! Something that will definitely be done in the next version of Due Dates is to create an online application for users to use. This will make it ten-fold easier for the average person to go and use Due Dates. We will be using Wicket to do this. It should turn out really good.

In the GREEN with HackyStat!

THE DEVELOPMENT OF A SOFTWARE ICU

A software 'Intensive Care Unit' is basically a set of tools for assessing and maintaining project health. It is very much like a hospital's ICU, as it monitors health via vital signs, except that it is monitoring a software project. Of these vital signs, some can give one a very clear idea of how a project is doing. Measures of this type include things like code coverage, complexity, coupling, code issues, and churn. For instance, if a project has bad code coverage, it is invariably lacking in some areas, thus being less 'healthy' than it should be. There are also measures like build counts, unit test counts, project size and development time, which give project health indications. However, with these measures, it is harder to say what is healthy and unhealthy since every project is different. They are there for one to manually interpret and analyze.

What's so interesting about a software ICU is its use in collaborative software. When there are projects being developed by multiple people all at once, its hard to know the current state of a project without manually running tests and doing analysis. When this is done, you then have to share these results with other teammates and that is another task in itself. With a software ICU, daily builds can send vital sign information to a central tool that analyses all the results in an effective way. This way, all project members are able to see the projects current status at any point, from anywhere. Everyone can see how everyone else is working on a project, as well as how consistent code is committed. A software ICU is a valuable tool for doing all of this.

Hackystat, developed by Philip Johnson, is one such tool for measuring a projects overall 'health.' Scheller and I decided to set it up to monitor our Due Dates project, along with the other teams working on their versions of Due Dates.

USING THE HACKYSTAT SYSTEM

Installing and using all the HackyStat sensors was a long, yet essentially easy task. Luckily, with the Due Dates project, Scheller and I were already using JUnit, Emma, CheckStyle, Findbugs, and PMD. This meant we only needed to install a few more tools on our system. These included SCLC, Javancss, and DependencyFinder. The eclipse plug-in worked seamlessly with the IDE. That took no time at all to install. Integrating the Ant sensor was just as easy.

The main problem I ran into was getting the svn sensor to work. When I initially went through the hackystat tutorial, I did not have to set up anything regarding username and passwords since everything was passed through the command line:

ant -Ddefault.account= -Ddefault.password= -Ddefault.sensorbase= -f svn.build.xml

I forgot about this when using it on the Due Dates system so I kept getting errors. Luckily hackystat provides an abundance of user wiki pages to help solve these types of problems. I realized I had to create a UserMap.xml file that held those parameters for me. 

Other than that, I did not run into much trouble installing the system and its sensors. I set up a daily build task on hudson to build the system each day. I was really anxious to see how our system would hold up in the hackystat software ICU.

DUE DATES GOLD CURRENT HEALTH

After setting up everything to send data to the hackystat sensorbase, I was then able to check on the current health of our Due Dates system. I was relatively surprised by the results: 

Project View of Due Dates Gold in Hackystat Browser

All the vital signs are green, meaning our code is healthy. Our coverage is in the 90's and there are no code issues. In addition the complexity, coupling, and churn values are all very reasonable. I was pleased with these results, although there are many areas for health improvement. For one, our system could definitely add some more tests to the test suite. Although our coverage is good, our test case number is fairly low.

As more development goes into the Due Dates project these values are sure to change and there will be more trend history displayed. Hopefully our project will be able to stay in the green. I really think having a software ICU like HackyStat monitor a projects status is extremely valuable. It is a great way to see the overall health and status of a system, thus making it easier to make improvements. Software development on a whole is made more efficient.

The Release of Due Dates Version 1.1 [team gold]

For the last week and a half, my partner Scheller Sanchez and I have been working on Due Dates Version 1.1. This new version has many new features compared to the last one, including support for the Hawaii State Library, a sort option, as well as a within option. All in all what ended up happening to our original code was a lot of redesign, a lot of review, and then even more redesign. Visit the project homepage to check out how it turned out.

VERSION 1.1 DESIGN

A lot has changed in the design department of our Due Dates implementation. Some of the things we initially made for future extension, like the LibraryVault class, we found were obsolete for this version because they were not abstract enough. For this very reason, I redesigned the overall structure a lot, first by putting all the methods for every library in the LibraryVault class, and then by making the LibraryVault class an interface for each separate library to implement from. This, I think turned out to be quite efficient as one can now add libraries easily based on the interface.

Another big change in version 1.1 was the creation of the ItemDue object that holds information about a borrowed item. Using this object, we were able to create an overall List of all the items that were due, allowing the program to sort through them, as well as perform other functions on them.

Also, Due Dates version 1.1 uses the open source ArgParser libraries to parse the command line arguments. These libraries are super useful in specifying command line options and ranges of certain arguments. Using the argparser definitely added to the robustness of the overall system, and it will allow for future additions to the program as well.

TIME CONSTRAINTS WITH VERSION 1.1

Since the release of Due Dates 1.0, I have been loaded with huge amounts of school work. In the last week and a half I not only had two midterms, but two large midterm projects due, not including Due Dates. For me, this was the main thing that slowed progress down on developing the system. I really spent all my extra school time working on Due Dates and it still was not enough.

What I had to do to really get things done was reserve certain days for working on Due Dates, and just work extra hard on it during these times. Although it was not the best system for doing things, it worked out. It was also nice that the system was reviewed twice in this time, helping me to narrow down what the most important things were to do.

COMMUNICATION PROBLEMS AND GROUP PROCESS

Another thing that changed since the last release of Due Dates was communication between our group. It turned out to be much, much harder to meet up in person this week since Scheller and I both had huge amounts of other work to do. By last week wednesday, the original date for the release of the system, he was still unable to help out on Due Dates because he was stuck working on another project. It was hard to collaborate on things because of this.

When we met in person a few times we went over some issues to do as well as some design problems we had to solve. This was good, but it was far from planning everything out. At some point last week I realized I had to just start trying out my new design ideas for Due Dates version 1.1. This was not efficient since I was the only one doing things, and because of this I had to redesign the program a few times over. Things didn't run as smoothly as they did with the release of version 1.0.

Sometimes it took awhile to contact Scheller, but eventually I would get some sort of answer. Luckily we could communicate via instant messages, and luckily we were using configuration management software. It could have been worse. The truth is this version of Due Dates probably could have been better if we had worked more together on it. We did our best for the time period, and I tried my best to release the program up to specifications. I hope for the next release of the program I will be able to meet up with my group a lot more in person. That seems to be the best route for creating collaborative software.

WORKING WITH THE HUDSON SERVER (Continuous Integration)

For the development of version 1.1 we had access to the 'Hudson' server, which is used for the continuous integration of our system. This was, to say the least, really, really, really useful. I could not believe how many times a build would fail on there when I was positive I just checked it on my home machine. On one occasion, I would fix some problems that were found and that would cause even more problems (this had to do with declaring 'private final static' variables and the order of those words). I would commit thinking that everything was a-okay, but the build would fail and hudson let me know each time. Having a back up check using continuous integration is essential.

On the other hand, it was a bit much to always have the system build on Hudson. On many occasions I wanted to commit my code to the server for my partner to look over but the code did not pass verify due to QA errors that popped up. I would always end up spending a long time fixing these errors, when all I wanted to do was commit the code I had so far to show my partner, regardless of the errors. For a while I ended up committing code that would fail the build because of this. That's why we probably still have 'cloudy skies' on hudson.

FINAL THOUGHTS

Overall, working on Due Dates version 1.1 was a lot more of a challenge compared to version 1.0. There were a lot of factors that caused this (time constraints, group process, etc), but I still believe the final outcome turned out great. The program runs nicely now and has all the functionality needed. It is now very extendable too! Developing the next version of the system will be interesting.

Some of the other teams also did great implementations of Due Dates for version 1.1. One worth checking out is Due Dates (Team Silver). I did a review on their system and it is just really awesome. Watch out for the next version of Due Dates coming soon...

Software Review Part Deux

After much time was spent re-working and changing the Due Dates [Team Gold] system to include new standards, Scheller and I were assigned to do a software review on Team Silver's Due Dates program, as well as have our system reviewed by Team Orange. This turned out to be a real eye opening experience for me, as I saw what other groups were capable of and what could be improved on our teams implementation. Since last weeks software review, I didn't really know what to expect since I was reviewing a new groups system.

REVIEW TEAM SILVER

Ronn Reeves and Robin Raqueno were the developers of this Due Dates system and it really was a pleasure reviewing their system. My first impression after viewing just their homepage was WOW. 

I mean look at that page! Compared to what I saw last week in other projects and what my own project homepage looks like, I was blown away. This project was definitely portrayed in an informative and professional way. I loved this. But how did the actual code fair?

After downloading their source code and checking it all out, I was not surprised to see top notch code. Their package structure was organized nicely, as was their class structure. Everything functioned correctly and was done really well. I found their system could really be extended by anyone, even the user. This was because libraries were added through an xml file where the data for each library was held, and this could be updated. I was very impressed by this function. It really was a task to find anything serious to comment on in their code, but I found a few things here and there worth noting.

What was interesting was to see how this team implemented ArgParser, and open source command line parser, since we had also implemented that in our system. Not only did they implement the parser to work for correct arguments like -uhm 12345567 wolff, they made it work for arguments without the library declaration, something more like 12345567 wolff. This was a pretty cool thing I thought, since it would minimize user errors when adding command line arguments.

Overall, doing this review was really nice. It was intriguing to see how a top notch team implemented their system. I think I was able to help as well, if not with their actual code, but with their user/developer guides which were missing a few important things (Their results). In addition to all of this, I got some new ideas for our system.

TEAM ORANGE'S REVIEW ON OUR PROJECT

A review on our Due Dates system was really needed and luckily we had an excellent review team do it - Team Orange, Daniel Tian and Aric West. Our initial review page outlined everything we wanted to have reviewed and they responded to basically everything we asked for and more. I was expecting comments on our class structure, testing and a few other areas, but they found some things I would have never found on my own that were of equal importance. After refactoring our system to have the DueDates name instead of the DueDatesGold name, I forgot that this screwed up jar creation and basic building capabilities. They caught this. There were also some really great comments on the code itself. They gave some great suggestions on some general design issues that needed to be addressed.

I think it is so important to have others try to build and run your system, especially when your dealing with an Open Source Software development project. Many things like jar creation work perfectly on our computers where we've developed everything, but once someone else tries to do these things on another machine, there are errors. Having a review done like this is great for pointing out these errors.

GOOGLE PROJECT HOSTING REVIEW

Doing this review was fairly similar to doing it the last time. Adding comments to peoples code was easily done and check-out was easy. However, I found it much easier to read the comments on our system, as they are all logged on one overall page. Something funny that did happen though was when Daniel Tian did his review and half of his comments appeared on r39, while the others appeared on r40. We couldn't figure it out.

A function I would love google to implement is something that sends you the info about your review that you've done. I have no way of accessing the review I did on Team Silver's system. The only way would be to get a link from them. It could be made easier if that were automated, or if there was a dedicated page for it all.

Overall, this software review was a great experience for me. I sort of got inspired from looking at Team Silvers code, and Team Orange really gave our group some good ideas for improving our system.