Java Weekly #9: Money, retired DTOs, JSR for MVC, JDK tools aand more...

The Java world is evolving at a rapid pace and it can be challenging to keep track of it. Fortunately lots of great resources are created every week, explaining new features or looking at existing stuff from a different angle.

I am using the Java Weekly series to collect the most interesting links I found during the last week and present them to you all in one place. I hope you find it useful and that it makes it easier for you to keep up-to-date. If you like to suggest a resource or something I can improve on, please leave me a comment.

Java

Everyone who had to deal with money in Java knows, that it is not as easy as it seems. The JSR 354 - Money and Currency API has the goal to solve this by defining a standardized and easy to use API. The work on this JSR is still in progress and it might be part of Java 9.
If you like to get an overview about the API, you should have a look at Java 9 is coming with money api by Otávio Santana.

Java EE

As announced a few days ago, there will be a separate JSR for the Model-View-Controller Specification. It will be lead by Santiago Pericas-Geertsen and Manfred Riem from Oracle.
Joshua Wilson will join the expert group and explained the general idea and his goals for MVC JSR in a blog post.


The usage of Data Transfer Objects (DTOs) gets discussed quiet often. Some say they are essential to implement a Java EE application, others say you should never use them.
Last week, Adam Bien added two blog postings to the discussion. Java EE 7 Retired The DTO explains why DTOs are no longer needed with Java EE 7 and DTO: The Exceptions From The Rule shows the exceptions when you should use them.


There are lots of different tools to monitor your application in production. But do you really need them, if you only want to get an email if a certain error occurs?
Roberto Cortez shows in his blog post Monitoring and Filtering Application Log to Mail with log4j how to use log4j to trigger an email based on a certain log message.


Abhishek Gupta posted the second part of his great series about lifecycle and concurrency models for EJB 3.x:

• EJB 3.x : Lifecycle and Concurrency models (part 1)
• EJB 3.x : Lifecycle and Concurrency models (part 2)

After explaining the lifecycle and concurrency model for Stateful and Stateless Session Beans in Part 1, he now describes it for Singleton EJBs in Part 2.

Tools

The JDK ships with lots of useful command line tools. Oleg Shelajev describes 6 build-in JDK tools the average developer should learn to use more in his current blog post and even more in the bonus section.

Microservices

Microservices are the current hot topic in software development. Developing smaller services without a huge amount of legacy code shall result in a better modularity, scaleability and more fun during development. But there is no free lunch! Martin Fowler describes the consequences for your operations team and the required competencies in his post MicroservicePrerequisites.

This and that

Staying relevant as an IT professional is a challenge we all have to face. If you are wondering how to do this, Petri Kainulainen gives you the 5 things he does to stay relevant.
I completely agree with his list and I do the same. But I would like add one additional thing, if you want to stay relevant, you should also read my Java Weekly every Monday! (Sorry, couldn't resist ;-))

Done!

These were the most interesting resources I found this week. I hope you find them useful and I see you next Monday for the next issue. You can subscribe below to get an email notification for every issue.

If you like to suggest a link for next weeks issue or something i can improve on, please write me a comment.