Wednesday, October 09, 2013

TigerTeam TRIMM - Model Driven Generator just went Open Source

TigerTeam TRIMM – Model Driven Generator is just Open Sourced in July 2013. I myself never heard of this product before and found this product by coincidence as I tried to find a JPA 2 standalone cartridge / generator available in Internet. I know that AndroMDA has some cartridges to persist Java objects but as far as I know AndroMDA only support persistence in the context of EJB 3 not as standalone JPA.

After I found this product I began to analyze the code at Bitbucket.org and found out that the idea with the Events and Listeners as Extensions is a very good idea. TRIMM also uses Maven completely and does not have any dependencies to Eclipse plugins, so you are Eclipse independent. Special to this framework is that it uses its own metamodel and does not use UML2 metamodel for the generators. TRIMM should work for MagicDraw and Enterprise Architect and it can read the files directly from those UML tools. It also uses its own Java code generator which is basically based on String outputs. A very good thing is that TRIMM offers some ready to use cartridges like Java, JPA 2 and Webservice.

It seems that TRIMM does not suffer the problems I mentioned in my older Java article at Java Lobby post and uses almost the same approach of KissMDA. Following are the differences I can see in a glance:

(1) TRIMM is using its own Java generator which is basically based on String outputs and this is not the best way to generate Java codes. Using Eclipse JDT is a lot more easier and you always get syntactically correct Java codes which can be easily unit tested like this KissMDA example.

(2) Interesting to compare the transformers for Java code generation. In TRIMM you have the class JavaGenerator.java. In KissMDA you use the class SimpleJavaTransformer.java. They both are the main entering point for the generation of Java codes. Both classes look quite similar from the way of doing the works they need to do. Using DI framework like Guice in KissMDA makes the code more readable and easier to understand.

(3) Unit tests are crucial in KissMDA. The simple Java cartridge has in the mean time about 35 test cases. This is possible because we use Mockito extensively. TRIMM Java cartridge has also some unit tests which are not many in comparison with the available implementation classes.

I really like the idea of using Events and Listeners to plug the extensions. In this context I will try to write the next KissMDA cartridge which will be a JPA 2 cartridge using Events, Event Bus and Listeners. As a foundation I will use this easy and simple Event Binder framework: GWT Event Binder. In the mean time I found some Open Source Event Bus implementations like Guava and MBassador. This is a good blog which compares those Event Bus frameworks: Java Event Bus Library Comparison. My choice is MBassador because it supports Weak References in Event Bus.

Congratulation to the team of TRIMM and I  think, it is a very good move to Open Source TRIMM. I wish all the best for the future of TRIMM!

Monday, July 01, 2013

CDI vs. Spring Framework Core

Another question I got in my Spring Framework training is: is it worthwhile to switch from Spring Framework 3.x to CDI with JBoss Weld or Apache OpenWebBeans implementation?

After googling around I found some good articles and blogs about this topic. These two articles are the best in my opinion:
Luckily I had a chance to take a CDI course intensively for two days to be able to see what we actually could do with CDI. After doing two days intensive course of CDI I can sum up this topic as following:
  • CDI takes a lot of good idea of Spring Framework, this is for sure.
  • Anything you can do with CDI (I used JBoss Weld in the course I followed) is not new and you can have those stuffs in Spring Framework as well.
  • In CDI 1.0 (JEE 6) there is still a lot of things which is not supported natively such as "scanning of classes and packages" to turn on the dependency injection. Sure you can use CDI portable extensions to support such a functionality but the problem with those extensions is just like Eclipse plugins: you never know whether all of the plugins can work smoothly together if they are not written by one person or one vendor.
Additionally to the articles and blogs above I found following extensions for Spring Framework to support following CDI mechanism:
(1) Events with @Observes: take a look at this Open Source project which extends Spring capability: spring-event-annotations.

(2) Decorator with @Decorator and @Delegate: take a look at this blog and Open Source project: JSR-299 CDI Decorators for Spring beans.

(3) Interceptor with @Interceptor, @InterceptorBinding, @AroundInvoke and @Nonbinding: take a look at this article: JSR-299 CDI Interceptors for Spring Beans.

(4) Custom bean scope: take a look at this article: Custom scopes in CDI 1.0 and Spring 3.1.

(5) Type-safe injection: take a look at this blog: Type-safe dependency injection in Spring 3 IoC-Container.

At the end I have to admit that you won't miss anything if you are using Spring Framework. It is definitely more mature than any other Context and Dependency Injection containers available on the market. So if you ask me whether it is worthwhile to switch from Spring Framework Core to CDI implementation like JBoss Weld I would say: no.There is also no economically reasons to switch to CDI implementation if you are already use Spring Framework. Try explain to your management that you want to switch to CDI just because it is standard, no other advantages and also with less functionality and maturity. Surely you should use the standard Annotations within Spring Framework, so instead of @Autowired you should use @Inject for example. In some ways I see Spring Framework Core as "the" reference implementation of CDI specification.

Cheers,
Lofi.

Tuesday, June 18, 2013

Creating Spring Bean dynamically in the Runtime

In my training someone asked me whether it is possible to create an object (a Spring Bean) dynamically so you can choose which implementation you want to have in the runtime. So at the compile time you don't know what object actually should be created yet. The application should decide what object to be created based on a property file.

1. We create an annotation so we can mark the method which should be able to create the object dynamically:

...
package your.package;
...
@Retention(RetentionPolicy.RUNTIME)
public @interface InjectDynamicObject {
}
...

2. Use the new created annotation in your method which should be able to create the object dynamically:

...
@Named("customerBo")
public class CustomerBoImpl implements CustomerBo {
...
    @Override
  @InjectDynamicObject
  public Customer getDynamicCustomer() {
        return this.dynamicCustomer;
}
...

3. Write an aspect with Pointcut and Advise which change the object returned by the method in the step 2:

...
@Named
@Aspect
public class DynamicObjectAspect {

    // This comes from the property file 
@Value("#{objects.object}")
private String object;

@Inject
private ApplicationContext applicationContext;

@Pointcut("execution(@your.package.InjectDynamicObject * *(..))")
public void beanAnnotatedWithInjectDynamicObject() {
}

@Around("beanAnnotatedWithInjectDynamicObject()")
public Object adviceBeanAnnotatedWithInjectDynamicObject(
ProceedingJoinPoint pjp) throws Throwable {
Object returnResult = pjp.proceed();
       // Create the bean or object depends on the property file
Object createdObject = applicationContext.getBean(object);
return createdObject;
}
}
...

4. Write your unit test to test the method:

...
    @Test
public void testCustomerOnlineOrOffline() {
// Dynamic object creation
System.out.println("DYNAMIC CUSTOMER: "
+ customerBo.getDynamicCustomer().getName());
}
...

OK, there is another easier way to do this ;-) Without Aspects and AspectJ, just pure Spring:

Just inject all your component implementations into a Map and get the correct implementation out of it. Just like what we have done in eXTra Client application. Please take a look at our implementation of PluginsLocatorManager as an example: http://goo.gl/itpcb. Spring injects the Map with Bean name as String and the Bean itself automagically. "... Even typed Maps can be autowired as long as the expected key type is String. The Map values will contain all beans of the expected type, and the keys will contain the corresponding bean names" (see Spring documentation for details).

...
@Named("customerBo")
public class CustomerBoImpl implements CustomerBo {
...
    // We inject the customer implementations into a Map
    @Inject
    private Map<String, Customer> customerDynamicMap;


    // This comes from the property file as a key for the Map
@Value("#{objects.object}")
private String object;
    
    @Override
  public Customer getDynamicCustomer() {
        return this.customerDynamicMap.get(object);
}
...

Have fun!
Lofi

Thursday, April 25, 2013

Software Development Macro and Micro Process

If you think that in year 2012 all companies which produce software and IT divisions in our world have already their optimized software development process, you are wrong. It seems that we - software architects, software developers or whatever your title is - still need to optimize the software development process in many software companies and IT divisions.

So what do you do if you enter a software company or IT division and you see following things:

1. There is a perfect project management process to handle all those development of software but it is a pure project management without a context to software development. So basically you only take care of cost, time, budget and quality factors. In the software development you still use the old fashioned waterfall process.

2. From the tooling point of view: you have a project management planning and controlling tool but you are still in the beginning of Wiki (almost no collaboration tool) and you don't use issues tracking system to handle all the issues for the development of your software components and applications. You use Winword and Excel to define your requirements and you cannot transform them to your software products since you don't have any isssues tracking system. No chance to have traceability from your requirements down to your issues to be done in your software components and applications.

3. Maven is already used but with a lot customization and not intuitively used. The idea of using a concrete already released version of dependencies was not implemented. Instead you always open all the dependently projects in Eclipse. You can imagine how slow Eclipse works since you need to open a lot of projects at once although you only work for one project. Versioning in Maven is also not used correctly e.g.: no SNAPSHOT for development versions.

4. As you work with webapp you always need to redeploy to the application server. No possibility to hot deploy the webapp. Use ctrl-s, see your changes and continue to work without new deployment is just a dream and not available.

Luckily as an experienced software architect and developer we know that we can optimize the two main software development processes:

1. Software Development Macro Process (SDMaP): this is the overall software development lifecycle. In this process model we define our requirements, we execute analysis, design, implementation, test and we deploy the software into production. Waterfall process model and agile process model like RUP and Scrum are examples of SDMaP.

2. Software Development Micro Process (SDMiP): this is the daily work of a software developer. How a software developer works to develop the software. A software developer codes, refactors, compiles, tests, runs, debugs, packages and deploys the software.

More information on SDMaP and SDMiP:
The picture below shows the SDMaP and SDMiP in combination. The macro (SDMaP) and micro (SDMiP) process meet at the implementation phase and activity. So changing and optimizing one has definitely side effects on the other one and vice versa.


At the example of organization mentioned above it is important that we optimize both processes since they work hand in hand. So how can the optimization for macro and micro process looks like?

1. SDMaP:
  • Introduce Wiki for IT divisions and software companies. You can use WikIT42 to make the structure of your Wiki and use Confluence as your Wiki platform.
  • Introduce Wiki with issue tracking like JIRA and combine both of them to track your requirements.
  • Refine the requirements into issues (features, tasks, bugs, etc.) to the level of the software components and applications, because at the end you will implement all the requirements using your software components and applications.
  • Introduce iterative software development lifecycle instead of waterfall process. This is a long way to go since you need to change the culture of the company and you need a full support from your management.
2. SDMiP
  • Update the Maven projects to use the standard Maven mechanism and best practices with no exception. Transform the structure of the old Maven to the new standard Maven using frameworks like MoveToMaven
  • Use Maven release plugin to standardize the release mechanism of all Maven projects.
  • Use m2e Eclipse plugin to optimize your daily work as a software developer under Eclipse and Maven.
  • Use Mylyn to integrate your issue tracking system like JIRA into your Eclipse IDE.
  • Introduce JRebel to be able to hot deploy quickly your webapps into the application server.
Optimizing macro and micro process for software development is not an easy task. In the macro process you need to handle all those relationships with other divisions like Business Requirements, Quality Assurance and Project Management divisions. You need to convince them that your SDMaP optimization is the best way to go. This is more an organizational challenge and changes than the micro process optimization.

The micro process is also not easy to optimize, since you need to convince all developers that they can be more productive with the new way of working than before. You need to show them that it is a lot more faster if you don't open a lot of Java projects within your Eclipse workspace. Also using JRebel to deploy your webapp to your application server is the best way to go. Normally developers are technical oriented, so if you can show them the cool things to make, they will join your way.


Friday, January 04, 2013

New Article about MDA at heise.de

Checkout my newest article about Model Driven Software Development with UML and Java at heise.de (in German language): Modellgetriebene Softwareentwicklung mit UML und Java - Besser als der Ruf.