A little bit overwhelming.

A lot of good material but it is way too much to digest in just 4 days.

I wish training companies would offer scheduling alternatives to these straight X days hellish setup. I think that offering 2 half days a week for a month would be easier to digest.

After taking this course I have a voucher to go try the exam. I will take it and to prepare I received a few advices that I like:

1. Set a date for the exam so you have the deadline motivation working for you
2. Use the study guide questions from Spring Source
3. Write all the answers on a cheat sheet and carry it with you every where you go to read it over and over
4. Redo all the labs and test alternative solutions

So by Monday I will have my schedule written down and I will start on my certification path. I know that it will be a lot of work but I see all the benefits from it and that motivates me more than the deadline.

Today I saw this site to create sequence diagrams which not only offers you a quick way to create your sequence diagram but offers a very simple API so you can embed it in your own site or application.

Good idea, well delivered.

One thing that I learned on this one was how to create the assembly file. This is very useful to bundle the project and be ready to deploy. This project is not a purely web app so we have all sorts of other files to bundle to be ready for deployment.

Maven has good documentation but when you are new to everything it takes a little while to sometimes find the right syntax to do what you want.

There was good documentation in this blog entry from Andrew E. Bruno to give me some basic understanding of what I needed to do. The key thing was that the assembly file needs to be in src/assemble and can be named as you wish. It also tells you what to add to your pom.xml to make this work.

I also had to read the Maven documentation about all the keywords that can be used in the assembly file. I wanted to remove the project name from the path in my tar.gz file. I simply needed to add:

<includeBaseDirectory>false</includeBaseDirectory>

right after the formats and everything was clean for my assembly process.

There is probably a few other things I will want to complete with other plugins but this is a good start to simplify the deployment of this project.

I found this other reference to add it to the pom.xml as a build section under the dependencies. That worked like a charm within seconds.

So here is my pom.xml with the Main-Class addition:

 <project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
 xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
 <modelVersion>4.0.0</modelVersion>

<groupId>com.cinq.test</groupId>
<artifactId>project1</artifactId>
<version>0.1.0</version>
<packaging>jar</packaging>

<name>project1</name>
<url>http://maven.apache.org</url>

<properties>
<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
</properties>

<dependencies>
<dependency>
<groupId>junit</groupId>
<artifactId>junit</artifactId>
<version>3.8.1</version>
<scope>test</scope>
</dependency>
</dependencies>
<build>
<plugins>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-jar-plugin</artifactId>
<version>2.3.1</version>
<configuration>
<archive>
<manifest>
<mainClass>com.cinq.test.App</mainClass>
</manifest>
</archive>
</configuration>
</plugin>
</plugins>
</build>
</project>

References:

http://maven.apache.org/guides/getting-started/index.html#How_do_I_add_resources_to_my_JAR

http://www.avajava.com/tutorials/lessons/how-do-i-specify-a-main-class-in-the-manifest-of-my-generated-jar-file.html

Note:

I initially forgot to specify the version for the maven-jar-plugin and maven gave me a detailed message to get it fixed:

[WARNING]
[WARNING] Some problems were encountered while building the effective model for com.cinq.test:mvntest:jar:0.1.0
[WARNING] ‘build.plugins.plugin.version’ for org.apache.maven.plugins:maven-jar-plugin is missing. @ line 28, column 15
[WARNING]
[WARNING] It is highly recommended to fix these problems because they threaten the stability of your build.
[WARNING]
[WARNING] For this reason, future Maven versions might no longer support building such malformed projects.
[WARNING]

We have an application that can list all items tracked in a table. The convenience is for users to quickly do global searches or to import this data in excel to do the manipulation they need.

When the table reached 1500 elements I received emails asking me what I changed to make it so slow in IE.

After some testing I realized that IE was rendering that web page in “quirks mode” which is not very efficient with large table.

After looking for a few minutes on Google I found an MSDN article talking about adding this header to tell IE to use the latest rendering engine for this page:

It is now applied across the site and IE9 performs fine but IE8 still shows some signs of slowness. Maybe more a computer issue that an IE issue but I can’t verify.

During my search on this IE issue I certainly came across a fair amount of displeased programmer with how IE does things (even in newer version) and I can see why. Hopefully I won’t be bitten too often.

No reason to doubt an experienced programmer so I changed my code.

I never trusted anyone when I did troubleshooting before. I always need to see the evidence for myself. So I decided to do this code to check the validity of the data I was given:

/**
 * Testing the performance of different ways to go through a list of items
 */
package com.cinq.test;

import java.util.ArrayList;
import java.util.Iterator;
import java.util.NoSuchElementException;

/**
 * @author mc
 * @version 0.1.0
 *
 * last updated on 2011-11-27
 *  initial release of these tests
 */
public class Performance {

    /**
     * @param args
     */
    public static void main(String[] args) {

        long dstart = 0;
        long dend = 0;

        // Allocate an ArrayList
        ArrayList<String> data1 = new ArrayList<String>();
        ArrayList<String> data2 = new ArrayList<String>();
        for ( int i = 0; i < 10000; i++ ) {
            data1.add("abc" + String.valueOf(i));
            data2.add("xyz" + String.valueOf(i));
        }

        // Start going through all the elements with a get index method
        dstart = System.currentTimeMillis();
        for ( int j = 0; j < data1.size(); j++ ) {
            data1.get(j);
            for ( int k = 0 ; k < data2.size(); k++) {
                data2.get(k);
            }
        }
        dend = System.currentTimeMillis();

        System.out.println("Get Index for " + data1.size() + " by " + data2.size() + " elements took " + (dend - dstart) + " ms.");

        dstart = System.currentTimeMillis();
        for ( String s1 : data1 ) {
            for ( String s2 : data2 ) {
                // nothing
            }
        }
        dend = System.currentTimeMillis();

        System.out.println("For each for " + data1.size() + " by " + data2.size() + " elements took " + (dend - dstart) + " ms.");

        dstart = System.currentTimeMillis();
        Iterator<String> it1 = data1.iterator();
        try {
            while ( it1.next() != null ) {
                try {
                    Iterator<String> it2 = data2.iterator();
                    while ( it2.next() != null ) {
                        //nothing
                    }
                } catch ( NoSuchElementException e0 ) {
                    //ignore
                }
            }
        } catch ( NoSuchElementException e1 ) {
            // ignore
        }
        dend = System.currentTimeMillis();

        System.out.println("Iterator for " + data1.size() + " by " + data2.size() + " elements took " + (dend - dstart) + " ms.");
    }

}

The output I get from this is:

Get Index for 10000 by 10000 elements took 12 ms.
For each for 10000 by 10000 elements took 271 ms.
Iterator for 10000 by 10000 elements took 166 ms.

This makes no sense. I should see the performance of the Iterator way of doing things to be faster than my get(index) way. I will have to ask my co-worker tomorrow why I am getting this bad performance. Conclusion to follow in the next few days.

I just completed some code and I was wondering if using the return code for errors was a good idea or if I should have used exceptions everywhere.

After reading a few articles I think that I did the right thing.

One key sentence that I like is: exceptions are for exceptional conditions. So you should see an exception if the failure is not expected and abnormal to the working of your application. A good point.

Others are saying that you should crash loudly. They are saying to use exceptions as much as possible so that it gets your attention and you fix the issue sooner than later.

The argument that return code makes the application more stable seems to be a bit simplistic because you might be hiding issues that will be more difficult to identify later.

There is room for both approach and I think that experience tells you what to do. Always using one or the other does not seem to make sense. Balance.

Return code makes sense right now because this Java code needs to integrate with some Bash code. If the solution was purely Java I think that I would need to change this strategy.

I may start using more checked exceptions since it gives me a better sense of balance and allows to have more information about the failure.

Continuous improvements.

It was great help to find the documentation/code for the library I was using. They only claim to have index for Java, JBoss and Eclipse but the F5 library was there as well.

I installed the Eclipse plugin because that could save some time when searching why I am getting a certain error or why some code is not working as expected.

You find new things every day.

http://marxsoftware.blogspot.com/2011/10/javaone-2011-definitive-set-of-hotspot.html

It is also funny that the small, almost irrelevant, option is the one that will relieve a serious pain for me:

-XX:+PrintGCDataStamps If this works as I expect we will be able to read GC logs and easily figure out when events have happened


How to be an exception photographer

This article highlights the fact that you need to focus on something you like and you are good at. You keep working on it and you become better. This is the way to plan your future compared to trying to being good at everything which will fail you sooner than later.

I have read enough of these articles to know these simple principles. What they also admit in the article is that it is not always easy to find where you are and where you should go. They have a few questions that you should ask yourself and answer honestly to be able to find where you want to go.

They key to success is having a realistic plan and actioning it. Keep working at it. Wishing for results is not enough.